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Zhang W, Jiang J, Liu T, Wang X, Zhang W, Wang Y, Chu Z, Jin W. A rapid and ultrasensitive cardiac troponin I aptasensor based on an ion-sensitive field-effect transistor with extended gate. Talanta 2024; 277:126364. [PMID: 38861763 DOI: 10.1016/j.talanta.2024.126364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/27/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024]
Abstract
Acute myocardial infarction (AMI) is a life-threatening disease with a short course and a high mortality rate. However, it is still a great challenge to achieve the on-site diagnosis of this disease within minutes, meaning there is an urgent need to develop an efficient technology for realizing the rapid diagnosis and early warning of AMI in clinical emergencies. In this study, an ultrasensitive electrochemical aptasensor based on an extended-gate ion-sensitive field-effect transistor (EGISFET) was designed to achieve the quantitative assay of cardiac troponin I (cTnI), which is a highly sensitive and specific biomarker of AMI, within only 5 min. The EGISFET exhibits extremely high detection sensitivity due to its separated structure with a large sensing area and the surface-modified Prussian blue-gold nanoparticles (PB-AuNPs) composite, which serves as a signal magnifier and DNA loading platform for good electrocatalytic ability with a large specific area. Additionally, a target-induced strand-release strategy is proposed to shorten the recognition time of cTnI using a particular DNA strand. Under optimal conditions, the as-prepared aptasensor exhibits a wide linear range of 1-1000 pg/mL, an ultralow detection limit of 0.3 pg/mL, and reliable detection results in real serum samples. It is highly anticipated that this EGISFET-based aptasensor will have broad applications in the early warning and rapid diagnosis of AMI and other acute diseases in emergency treatment.
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Affiliation(s)
- Wei Zhang
- College of Electrical Engineering and Control Science, Nanjing Tech University, Nanjing, 211816, PR China
| | - Jidong Jiang
- College of Electrical Engineering and Control Science, Nanjing Tech University, Nanjing, 211816, PR China
| | - Tao Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; College of Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Xun Wang
- College of Electrical Engineering and Control Science, Nanjing Tech University, Nanjing, 211816, PR China
| | - Wei Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, PR China
| | - Yiqing Wang
- College of Electrical Engineering and Control Science, Nanjing Tech University, Nanjing, 211816, PR China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China.
| | - Zhenyu Chu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; College of Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Wanqin Jin
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; College of Chemical Engineering, Nanjing Tech University, Nanjing, 211816, PR China.
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2
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Dines B, Kellihan H, Allen C, Loynachan A, Bochsler P, Newbury S. Case report: Long-term survival in puppies assessed with echocardiography, electrocardiography and cardiac troponin I after acute death in littermates due to parvoviral myocarditis. Front Vet Sci 2023; 10:1229756. [PMID: 37645673 PMCID: PMC10462392 DOI: 10.3389/fvets.2023.1229756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 07/24/2023] [Indexed: 08/31/2023] Open
Abstract
Positive clinical outcomes of a group of surviving puppies from a litter affected by parvoviral myocarditis are detailed in this case report. Past reports focus on the negative outcomes of littermates of puppies who have died of parvoviral myocarditis. In this case, two puppies in a shelter setting, from a litter exposed to parvovirus, died suddenly with parvoviral myocarditis diagnosed at necropsy. The other seven puppies were screened for cardiac health with echocardiogram, electrocardiogram, and cardiac troponin I prior to adoption. All seven puppies had normal echocardiograms, electrocardiograms, and normal initial and recheck cardiac troponin I results. At recheck 2 years after the initial round of testing, two of the puppies were screened and continue to have normal cardiac diagnostics. All seven dogs are alive and thriving at 5 years old in homes with adopters who were given a complete medical history on the dogs prior to adoption. In summary, the outcomes for puppies in litters affected by parvoviral myocarditis are variable but they do not have to be grave. The use of cardiac diagnostics including echocardiogram, electrocardiogram and cardiac troponin I may serve as a prognostic basis for assessing the potential outcomes for the surviving puppies in affected litters.
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Affiliation(s)
- Brenda Dines
- Department of Medical Sciences, University of Wisconsin-Madison School of Veterinary Medicine Shelter Medicine Program, Madison, WI, United States
| | - Heidi Kellihan
- Department of Medical Sciences, University of Wisconsin-Madison School of Veterinary Medicine, Madison, WI, United States
| | - Carolyn Allen
- Department of Medical Sciences, University of Wisconsin-Madison School of Veterinary Medicine Shelter Medicine Program, Madison, WI, United States
| | - Alan Loynachan
- Department of Veterinary Science, University of Kentucky Veterinary Diagnostic Laboratory, Lexington, KY, United States
| | - Philip Bochsler
- Department of Pathobiological Sciences, Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin-Madison School of Veterinary Medicine, Madison, WI, United States
| | - Sandra Newbury
- Department of Medical Sciences, University of Wisconsin-Madison School of Veterinary Medicine Shelter Medicine Program, Madison, WI, United States
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3
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Wu C, Gao X, Li L, Jing Q, Li W, Xu H, Zhang W, Li S, Zhao Y, Wang Y, Li W, Wu Y, Hu F, Jin C, Qiao S, Yang J, Yang Y. Role of ST-Segment Resolution Alone and in Combination With TIMI Flow After Primary Percutaneous Coronary Intervention for ST-Segment-Elevation Myocardial Infarction. J Am Heart Assoc 2023:e029670. [PMID: 37449560 PMCID: PMC10382099 DOI: 10.1161/jaha.123.029670] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
Background To evaluate the role of ST-segment resolution (STR) alone and in combination with Thrombolysis in Myocardial Infarction (TIMI) flow in reperfusion evaluation after primary percutaneous coronary intervention (PPCI) for ST-segment-elevation myocardial infarction by investigating the long-term prognostic impact. Methods and Results From January 2013 through September 2014, we studied 5966 patients with ST-segment-elevation myocardial infarction enrolled in the CAMI (China Acute Myocardial Infarction) registry with available data of STR evaluated at 120 minutes after PPCI. Successful STR included STR ≥50% and complete STR (ST-segment back to the equipotential line). After PPCI, the TIMI flow was assessed. The primary outcome was 2-year all-cause mortality. STR < 50%, STR ≥50%, and complete STR occurred in 20.6%, 64.3%, and 15.1% of patients, respectively. By multivariable analysis, STR ≥50% (5.6%; adjusted hazard ratio [HR], 0.45 [95% CI, 0.36-0.56]) and complete STR (5.1%; adjusted HR, 0.48 [95% CI, 0.34-0.67]) were significantly associated with lower 2-year mortality than STR <50% (11.7%). Successful STR was an independent predictor of 2-year mortality across the spectrum of clinical variables. After combining TIMI flow with STR, different 2-year mortality was observed in subgroups, with the lowest in successful STR and TIMI 3 flow, intermediate when either of these measures was reduced, and highest when both were abnormal. Conclusions Post-PPCI STR is a robust long-term prognosticator for ST-segment-elevation myocardial infarction, whereas the integrated analysis of STR plus TIMI flow yields incremental prognostic information beyond either measure alone, supporting it as a convenient and reliable surrogate end point for defining successful PPCI. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01874691.
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Affiliation(s)
- Chao Wu
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Xiaojin Gao
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Ling Li
- Medical Research and Biometrics Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Quanmin Jing
- Department of Cardiology General Hospital of Shenyang Military Region Shenyang China
| | - Weimin Li
- Department of Cardiology The First Affiliated Hospital of Harbin Medical University Harbin China
| | - Haiyan Xu
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Wenbo Zhang
- Department of Epidemiology University Medical Center Groningen Groningen the Netherlands
| | - Sidong Li
- Division of Life Sciences and Medicine University of Science and Technology of China Hefei China
| | - Yanyan Zhao
- Medical Research and Biometrics Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Yang Wang
- Medical Research and Biometrics Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Wei Li
- Medical Research and Biometrics Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Yongjian Wu
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Fenghuan Hu
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Chen Jin
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Shubin Qiao
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Jingang Yang
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
| | - Yuejin Yang
- Department of Cardiology, Coronary Heart Disease Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease National Center for Cardiovascular Diseases Beijing China
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Ozturk O, Golparvar A, Acar G, Guler S, Yapici MK. Single-arm diagnostic electrocardiography with printed graphene on wearable textiles. SENSORS AND ACTUATORS. A, PHYSICAL 2023; 349:114058. [PMID: 36447633 PMCID: PMC9686048 DOI: 10.1016/j.sna.2022.114058] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/04/2022] [Accepted: 11/23/2022] [Indexed: 06/16/2023]
Abstract
Stimulated by the COVID-19 outbreak, the global healthcare industry better acknowledges the necessity of innovating novel methods for remote healthcare monitoring and treating patients outside clinics. Here we report the development of two different types of graphene textile electrodes differentiated by the employed fabrication techniques (i.e., dip-coating and spray printing) and successful demonstration of ergonomic and truly wearable, single-arm diagnostic electrocardiography (SADE) using only 3 electrodes positioned on only 1 arm. The performance of the printed graphene e-textile wearable systems were benchmarked against the "gold standard" silver/silver chloride (Ag/AgCl) "wet" electrodes; achieving excellent correlation up to ∼ 96% and ∼ 98% in ECG recordings (15 s duration) acquired with graphene textiles fabricated by dip-coating and spray printing techniques, respectively. In addition, we successfully implemented automatic detection of heartrate of 8 volunteers (mean value: 74.4 bpm) during 5 min of static and dynamic daily activities and benchmarked their recordings with a standard fingertip photoplethysmography (PPG) device. Heart rate variability (HRV) was calculated, and the root means successive square difference (rMMSD) metric was 30 ms during 5 min of recording. Other cardiac parameters such as R-R interval, QRS complex duration, S-T segment duration, and T-wave duration were also detected and compared to typical chest ECG values.
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Affiliation(s)
- Ozberk Ozturk
- Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Istanbul, Turkey
| | - Ata Golparvar
- Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Istanbul, Turkey
- Integrated Circuit Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002 Neuchâtel, Switzerland
| | - Gizem Acar
- Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Istanbul, Turkey
| | - Saygun Guler
- Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Istanbul, Turkey
| | - Murat Kaya Yapici
- Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Istanbul, Turkey
- Department of Electrical Engineering, University of Washington, 98195 Seattle, USA
- Sabanci University SUNUM Nanotechnology Research Center, 34956 Istanbul, Turkey
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5
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Kazama I, Kuwana R, Muto M, Nagano A, Fujimura R, Asada A, Tamada T, Shimoyama M. Subepicardial burn injuries in bullfrog heart induce electrocardiogram changes mimicking inferior wall myocardial infarction. J Vet Med Sci 2022; 84:1205-1210. [PMID: 35811132 PMCID: PMC9523291 DOI: 10.1292/jvms.22-0243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Using bullfrog hearts, we previously reproduced a ST segment elevation in electrocardiogram (ECG), mimicking human ischemic heart disease. In the present study, by inducing subepicardial
burn injuries on the inferior part of the frog heart ventricle, we could reproduce typical ECG changes observed in human inferior wall myocardial infarction, such as the marked elevation of
the ST segments in inferior limb leads (II, III, aVF) and their reciprocal depression in the opposite limb leads (I, aVL). Due to the decrease in Na+/K+-ATPase protein
expression, the resting membrane potential of injured cardiomyocytes shifted toward depolarization. Such induced electrical difference between the injured and intact cardiomyocytes was
thought to be responsible for the creation of “currents of injury” and the subsequent ST segment changes.
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Affiliation(s)
| | | | | | | | | | | | - Tsutomu Tamada
- Department of Respiratory Medicine, Tohoku University Graduate School of Medicine
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6
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Santilli R, Saponaro V, Carlucci L, Perego M, Battaia S, Borgarelli M. Heart rhythm characterization during sudden cardiac death in dogs. J Vet Cardiol 2021; 38:18-30. [PMID: 34710652 DOI: 10.1016/j.jvc.2021.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022]
Abstract
INTRODUCTION/OBJECTIVES Inherited or acquired arrhythmic disorders and cardiac disease have been associated with sudden cardiac death (SCD) in dogs. The electrical mechanism related to death in most of these cases is unknown. This retrospective study aimed to describe arrhythmic events in dogs that experienced SCD during Holter monitoring. ANIMALS, MATERIALS AND METHODS Nineteen client-owned dogs that experienced SCD during Holter examination were included. Clinical records from a Holter service database were reviewed, and both the rhythm preceding death and the dominant rhythm causing SCD were analysed. Clinical data, Holter diaries and echocardiographic diagnosis were also evaluated. RESULTS Structural heart disease was identified in 12/19 dogs (dilated cardiomyopathy in five dogs, arrhythmogenic right ventricular cardiomyopathy in four dogs, myxomatous mitral valve disease in two dogs, and suspected myocarditis in one dog), five of which had concurrent congestive heart failure. Sudden cardiac death was related to ventricular premature complexes or monomorphic ventricular tachycardia degenerating into ventricular fibrillation in 42% of dogs, polymorphic ventricular tachycardia, or torsade de pointes-like inducing ventricular fibrillation in 21%, and asystole or presumptive agonal pulseless electrical activity triggered by malignant bradyarrhythmias in 37%. CONCLUSIONS The most common rhythm associated with SCD in our population of dogs was ventricular tachycardia leading to ventricular fibrillation, although bradyarrhythmia-related SCD, possibly related to inappropriate vagal reflexes, was also a notable cause.
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Affiliation(s)
- R Santilli
- Clinica Veterinaria Malpensa, AniCura, Via G. Marconi 27, Samarate, Varese, 21017, Italy; Department of Clinical Sciences, Cornell University College of Veterinary Medicine, 930 Campus Road, Ithaca, NY, 14853, USA.
| | - V Saponaro
- Centre Hospitalier Universitaire Vétérinaire d'Alfort (CHUVA), Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, Maisons-Alfort, F-94700, France
| | - L Carlucci
- Scuola Superiore Sant'Anna, Istituto Scienze della Vita, Via Martiri della Libertà, 33, Pisa, 56100, Italy
| | - M Perego
- Clinica Veterinaria Malpensa, AniCura, Via G. Marconi 27, Samarate, Varese, 21017, Italy; Ospedale Veterinario I Portoni Rossi, Via Roma 57, Zola Predosa, Bologna, 40069, Italy
| | - S Battaia
- Clinica Veterinaria Malpensa, AniCura, Via G. Marconi 27, Samarate, Varese, 21017, Italy; Ospedale Veterinario I Portoni Rossi, Via Roma 57, Zola Predosa, Bologna, 40069, Italy
| | - M Borgarelli
- Virginia-Maryland College of Veterinary Medicine, 205 Duck Pond Dr, Blacksburg, VA, 24060, USA
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7
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Gottlieb LA, Dekker LRC, Coronel R. The Blinding Period Following Ablation Therapy for Atrial Fibrillation: Proarrhythmic and Antiarrhythmic Pathophysiological Mechanisms. JACC Clin Electrophysiol 2021; 7:416-430. [PMID: 33736761 DOI: 10.1016/j.jacep.2021.01.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/14/2021] [Accepted: 01/17/2021] [Indexed: 02/01/2023]
Abstract
Atrial fibrillation (AF) causes heart failure, ischemic strokes, and poor quality of life. The number of patients with AF is estimated to increase to 18 million in Europe in 2050. Pharmacological therapy does not cure AF in all patients. Ablative pulmonary vein isolation is recommended for patients with drug-resistant symptomatic paroxysmal AF but is successful in only about 60%. In patients in whom ablative therapy is successful on the long term, recurrence of AF may occur in the first weeks to months after pulmonary vein ablation. The early recurrence (or delayed cure) of AF is not understood but forms the basis for the generally accepted 3-month blinding (or blanking) period after ablation therapy, which is not included in the evaluation of the eventual success rate of the procedures. The underlying pathophysiological processes responsible for early recurrence and the delayed cure are unknown. The implicit assumption of the blinding period is that the AF mechanism in this period is different from the ablation-targeted AF mechanism (ectopy from the pulmonary veins). In this review, we evaluate the temporary and long-lasting pro- and antiarrhythmic effects of each of the pathophysiological processes and interventions (necrosis, ischemia, oxidative stress, edema, inflammation, autonomic nervous activity, tissue repair, mechanical remodeling, and use of antiarrhythmic drugs) occurring in the blinding period that can modulate AF mechanisms. We propose that stretch-reducing ablation scar is a permanent antiarrhythmic mechanism that develops during the blinding period and is the reason for delayed cure.
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Affiliation(s)
- Lisa A Gottlieb
- Electrophysiology and Heart Modelling Institute, University of Bordeaux, Pessac, France; Department of Experimental Cardiology, Amsterdam University Medical Centre, Academic Medical Centre, Amsterdam, the Netherlands
| | - Lukas R C Dekker
- Department of Electrical Engineering, University of Technology, Eindhoven, the Netherlands; Cardiology Department, Catharina Hospital, Eindhoven, the Netherlands.
| | - Ruben Coronel
- Electrophysiology and Heart Modelling Institute, University of Bordeaux, Pessac, France; Department of Experimental Cardiology, Amsterdam University Medical Centre, Academic Medical Centre, Amsterdam, the Netherlands
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Abstract
Hypermagnesemia occurs in elderly people or patients with renal insufficiency after
excessive ingestion of magnesium-containing laxatives. In addition to typical
electrocardiogram (ECG) findings caused by conduction defects, changes in the ST segments
and T waves are also observed in patients with severe hypermagnesemia. This suggested the
involvement of similar pathophysiology to acute myocardial infarction, as we previously
demonstrated using burn-induced subepicardial injury model in frog hearts. In the present
study, by exposing the bullfrog heart to high-magnesium solution, we reproduced prominent
ST segment changes in ECG as actually observed in patients with severe hypermagnesemia. In
addition to the great increase in the T waves, the ECG showed a marked elevation of the ST
segments and the cardiac action potential demonstrated a marked shift of the resting
membrane potential to the depolarized side. High-magnesium exposure did not affect the
abundance of Na+/K+-ATPase proteins. However, the pharmacological
stimulation of Na+/K+-ATPase activity by insulin quickly retrieved
the elevated ST segments in ECG. From these results, the functional blockade of
Na+/K+-ATPase activity by magnesium ions was thought to be
responsible for generating the potassium concentration gradient and the subsequent ST
segment changes.
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Affiliation(s)
- Itsuro Kazama
- School of Nursing, Miyagi University, Gakuen, Taiwa-cho, Kurokawa-gun, Miyagi 981-3298, Japan
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9
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He Z. The control mechanisms of heart rate dynamics in a new heart rate nonlinear time series model. Sci Rep 2020; 10:4814. [PMID: 32179768 PMCID: PMC7075874 DOI: 10.1038/s41598-020-61562-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/21/2020] [Indexed: 12/19/2022] Open
Abstract
The control mechanisms and implications of heart rate variability (HRV) under the sympathetic (SNS) and parasympathetic nervous system (PNS) modulation remain poorly understood. Here, we establish the HR model/HRV responder using a nonlinear process derived from Newton's second law in stochastic self-restoring systems through dynamic analysis of physiological properties. We conduct model validation by testing, predictions, simulations, and sensitivity and time-scale analysis. We confirm that the outputs of the HRV responder can be accepted as the real data-generating process. Empirical studies show that the dynamic control mechanism of heart rate is a stable fixed point, rather than a strange attractor or transitions between a fixed point and a limit cycle; HR slope (amplitude) may depend on the ratio of cardiac disturbance or metabolic demand mean (standard deviation) to myocardial electrical resistance (PNS-SNS activity). For example, when metabolic demands remain unchanged, HR amplitude depends on PNS to SNS activity; when autonomic activity remains unchanged, HR amplitude during resting reflects basal metabolism. HR parameter alterations suggest that age-related decreased HRV, ultrareduced HRV in heart failure, and ultraelevated HRV in ST segment alterations refer to age-related decreased basal metabolism, impaired myocardial metabolism, and SNS hyperactivity triggered by myocardial ischemia, respectively.
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Affiliation(s)
- Zonglu He
- Faculty of Management and Economics, Kaetsu University, 2-8-4 Minami-cho, Hanakoganei, Kodaira-shi, Tokyo, 187-8578, Japan.
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10
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11
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Kazama I, Takamura K, Yamada Y, Sugisaki Y, Suzuki M. Reciprocal ST segment changes reproduced in burn-induced subepicardial injury model in bullfrog heart. J Vet Med Sci 2019; 82:143-147. [PMID: 31827015 PMCID: PMC7041995 DOI: 10.1292/jvms.19-0597] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In our previous studies, by simply inducing burn injuries on bullfrog hearts or partially
exposing their surface to high-potassium (K+) solution, we could reproduce a ST
segment elevation in the electrocardiogram (ECG), which is a characteristic finding in
human ischemic heart disease. In the present study, using our burn-induced subepicardial
injury model, we could additionally reproduce “reciprocal” ST segment changes for the
first time in frog hearts, mimicking those observed in human acute myocardial infarction.
Immunohistochemistry demonstrated markedly decreased Na+/K+-ATPase
protein expression in the ventricular surface after the burn injury. The loss of this pump
expression in injured cardiomyocytes was thought to be responsible for the creation of
“currents of injury” and the subsequent ST segment changes observed in acute myocardial
infarction.
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Affiliation(s)
- Itsuro Kazama
- School of Nursing, Miyagi University, Gakuen, Taiwa-cho, Kurokawa-gun, Miyagi 981-3298, Japan
| | - Kano Takamura
- School of Nursing, Miyagi University, Gakuen, Taiwa-cho, Kurokawa-gun, Miyagi 981-3298, Japan
| | - Yukina Yamada
- School of Nursing, Miyagi University, Gakuen, Taiwa-cho, Kurokawa-gun, Miyagi 981-3298, Japan
| | - Yui Sugisaki
- School of Nursing, Miyagi University, Gakuen, Taiwa-cho, Kurokawa-gun, Miyagi 981-3298, Japan
| | - Mayu Suzuki
- School of Nursing, Miyagi University, Gakuen, Taiwa-cho, Kurokawa-gun, Miyagi 981-3298, Japan
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12
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High arrhythmic risk in antero-septal acute myocardial ischemia is explained by increased transmural reentry occurrence. Sci Rep 2019; 9:16803. [PMID: 31728039 PMCID: PMC6856379 DOI: 10.1038/s41598-019-53221-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 10/24/2019] [Indexed: 12/16/2022] Open
Abstract
Acute myocardial ischemia is a precursor of sudden arrhythmic death. Variability in its manifestation hampers understanding of arrhythmia mechanisms and challenges risk stratification. Our aim is to unravel the mechanisms underlying how size, transmural extent and location of ischemia determine arrhythmia vulnerability and ECG alterations. High performance computing simulations using a human torso/biventricular biophysically-detailed model were conducted to quantify the impact of varying ischemic region properties, including location (LAD/LCX occlusion), transmural/subendocardial ischemia, size, and normal/slow myocardial propagation. ECG biomarkers and vulnerability window for reentry were computed in over 400 simulations for 18 cases evaluated. Two distinct mechanisms explained larger vulnerability to reentry in transmural versus subendocardial ischemia. Macro-reentry around the ischemic region was the primary mechanism increasing arrhythmic risk in transmural versus subendocardial ischemia, for both LAD and LCX occlusion. Transmural micro-reentry at the ischemic border zone explained arrhythmic vulnerability in subendocardial ischemia, especially in LAD occlusion, as reentries were favoured by the ischemic region intersecting the septo-apical region. ST elevation reflected ischemic extent in transmural ischemia for LCX and LAD occlusion but not in subendocardial ischemia (associated with mild ST depression). The technology and results presented can inform safety and efficacy evaluation of anti-arrhythmic therapy in acute myocardial ischemia.
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Mott B, Ammi AY, Le DE, Davis C, Dykan IV, Zhao Y, Nugent M, Minnier J, Gowda M, Alkayed NJ, Kaul S. Therapeutic Ultrasound Increases Myocardial Blood Flow in Ischemic Myocardium and Cardiac Endothelial Cells: Results of In Vivo and In Vitro Experiments. J Am Soc Echocardiogr 2019; 32:1151-1160. [PMID: 31272838 DOI: 10.1016/j.echo.2019.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 04/30/2019] [Accepted: 05/16/2019] [Indexed: 12/23/2022]
Abstract
BACKGROUND Therapeutic ultrasound can reduce infarct size in a model of coronary thrombosis even when sonothrombolysis is ineffective. The aim of this study was to test the hypothesis that ultrasound-induced cardioprotection is mediated by molecules released from the vascular endothelium that increase myocardial blood flow (MBF) and also have direct tissue-salvaging effects. METHODS In vivo and in vitro experiments were performed using a 1.05-MHz transducer. For the in vivo experiments 10 control and 10 ultrasound-treated dogs undergoing occlusion of the left anterior descending coronary artery were studied. MBF was measured using myocardial contrast echocardiography. For the in vitro experiments, primary mouse cardiac endothelial cells were exposed to ultrasound at baseline or following oxygen-glucose deprivation and endothelial nitric oxide synthase phosphorylation as well as adenosine and the eicosanoids epoxyeicosatrienoic acids, dihydroxyeicosatrienoic acids, and hydroxyl-eicosatetraenoic acids were measured. RESULTS In vivo, ultrasound treatment caused higher MBF (20 ± 10 vs 10 ± 8, P = .03) and higher wall thickening (3 ± 3% vs 1 ± 0.4%, P = .01) in the collateral-derived border zone compared with control. Epicardial MBF in the left anterior descending coronary artery bed also tended to be higher (17 ± 17 vs 5 ± 4, P = .05) in ultrasound-treated versus control animals; however, endocardial MBF in this region was similar to that in controls (13 ± 14 vs 14 ± 7). In vitro, phosphorylated endothelial nitric oxide synthase and adenosine increased (by 129 ± 11% and 286 ± 63%, respectively, P < .01) with ultrasound compared with unstimulated cells. Similar results were obtained with epoxyeicosatrienoic acids. After oxygen-glucose deprivation, phosphorylated endothelial nitric oxide synthase decreased and was restored with application of ultrasound. Similar changes were noted with epoxyeicosatrienoic acids. Cell viability decreased with oxygen-glucose deprivation and returned to near baseline with ultrasound. CONCLUSIONS Ultrasound increases MBF in ischemic tissue in vivo. This effect is likely mediated by the release of a plethora of coronary vasodilators during ultrasound treatment that also have direct tissue-salvaging effects. Therapeutic ultrasound, therefore, has potential for treatment of acute and chronic myocardial ischemia independent of its effect on thrombolysis.
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Affiliation(s)
- Brian Mott
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon
| | - Azzdine Y Ammi
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon
| | - D Elizabeth Le
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon; Veterans Administration Portland Health Care System, Portland, Oregon
| | - Catherine Davis
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon; Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, Oregon
| | - Igor V Dykan
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon
| | - Yan Zhao
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon
| | - Mathew Nugent
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon
| | - Jessica Minnier
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon; Department of Biostatistics, Oregon Health and Science University, Portland, Oregon
| | - Mohanika Gowda
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon
| | - Nabil J Alkayed
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon; Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, Oregon
| | - Sanjiv Kaul
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon.
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Localization of the culprit artery in inferior myocardial infarction: Influence of the point of measurement of ST segment. J Electrocardiol 2019; 53:8-12. [DOI: 10.1016/j.jelectrocard.2018.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/03/2018] [Accepted: 12/13/2018] [Indexed: 11/23/2022]
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15
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Yang X, Jia X, Dong W, Wu S, Miller MR, Hu D, Li H, Pan L, Deng F, Guo X. Cardiovascular benefits of reducing personal exposure to traffic-related noise and particulate air pollution: A randomized crossover study in the Beijing subway system. INDOOR AIR 2018; 28:777-786. [PMID: 29896813 DOI: 10.1111/ina.12485] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 06/08/2018] [Indexed: 05/06/2023]
Abstract
To assess the cardiovascular benefits of protecting against particulate air pollution and noise, we conducted a randomized crossover study with 40 young healthy college students from March to May 2017 in the underground subway, Beijing. Participants each received 4 treatments (no intervention phase [NIP], respirator intervention phase [RIP], headphone intervention phase [HIP], respirator plus headphone intervention phase [RHIP]) in a randomized order during 4 different study periods with 2-week washout intervals. We measured personal exposure to particulate matter (PM), noise and electrocardiogram (ECG) parameters (heart rate variability (HRV), heart rate (HR) and ST segment changes), ambulatory blood pressure (BP) continuously for 4 hours to investigate the cardiovascular effects. Compared with NIP, most of the HRV parameters increased, especially high frequency (HF) [21.1% (95% CI: 15.7%, 26.9%), 18.2% (95% CI: 12.8%, 23.9%), and 35.5% (95% CI: 29.3%, 42.0%) in RIP, HIP, and RHIP, respectively], whereas ST segment elevation and HR decreased for all 3 modes of interventions. However, no significant differences were observed in BP among the 4 treatments. In summary, short-term wearing of a respirator and/or headphone may be an effective way to minimize cardiovascular risk induced by air pollution in the subway by improving autonomic nervous function.
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Affiliation(s)
- X Yang
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - X Jia
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - W Dong
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - S Wu
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - M R Miller
- University/BHF Centre for Cardiovascular Science, Queens Medical Research Institute, The University of Edinburgh, Edinburgh, UK
| | - D Hu
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - H Li
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - L Pan
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - F Deng
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - X Guo
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
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16
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Abstract
ST-segment elevation myocardial infarction is a major cause of morbidity and mortality worldwide. Reperfusion injury (RI) following the opening of an occluded coronary artery mitigates the effect of reperfusion by further accentuating ischemic damage and increasing infarct size. Experimental studies have shown that nearly 50% of final infarct size is attributable to RI, an elusive phenomenon that remains resistant to treatment. This review proposes a hypothesis to explain the failure of strategies that have been used in an attempt to prevent RI. This hypothesis suggests that, after a certain duration of myocardial ischemia in the affected myocardium, three phases of myocardial damage occur: reversible ischemia, irreversible ischemia, and necrosis. In the reversible ischemia phase, cellular adaptive responses remain functional, and cellular repair and thus recovery of cellular functions is possible, whereas in the irreversible ischemia phase protective maneuvers fail to confer cytoprotection. Preventive therapies for RI fail because they cannot prevent cell death once cells have entered the irreversible ischemia phase, although they may succeed in postponing cell death. Failure to salvage myocardium with irreversible ischemia in addition to postponement and change in the mode of cell death (mainly from necrosis to apoptosis) by various RI preventive strategies may be the key to understanding the failure of these strategies in the clinical setting, despite their success in the reduction of infarct size in the experimental setting. Early reperfusion before large amounts of myocardium at risk reach the stage of irreversible ischemia is the best strategy for reduction of RI-related myocardial damage.
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17
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Kon N, Abe N, Miyazaki M, Mushiake H, Kazama I. Partial exposure of frog heart to high-potassium solution: an easily reproducible model mimicking ST segment changes. J Vet Med Sci 2018; 80:578-582. [PMID: 29503350 PMCID: PMC5938182 DOI: 10.1292/jvms.18-0010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
By simply inducing burn injuries on the bullfrog heart, we previously reported a simple
model of abnormal ST segment changes observed in human ischemic heart disease. In the
present study, instead of inducing burn injuries, we partially exposed the surface of the
frog heart to high-potassium (K+) solution to create a concentration gradient
of the extracellular K+ within the myocardium. Dual recordings of ECG and the
cardiac action potential demonstrated significant elevation of the ST segment and the
resting membrane potential, indicating its usefulness as a simple model of heart injury.
Additionally, from our results, Na+/K+-ATPase activity was thought
to be primarily responsible for generating the K+ concentration gradient and
inducing the ST segment changes in ECG.
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Affiliation(s)
- Nobuaki Kon
- Department of Physiology, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Nozomu Abe
- Department of Physiology, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8575, Japan.,Department of Anesthesiology, Tohoku University Hospital, Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Masahiro Miyazaki
- Department of Physiology, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Hajime Mushiake
- Department of Physiology, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Itsuro Kazama
- School of Nursing, Miyagi University, Gakuen, Taiwa-cho, Kurokawa-gun, Miyagi 981-3298, Japan.,Department of Physiology, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8575, Japan
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18
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19
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Shanmugam G, Narasimhan M, Conley RL, Sairam T, Kumar A, Mason RP, Sankaran R, Hoidal JR, Rajasekaran NS. Chronic Endurance Exercise Impairs Cardiac Structure and Function in Middle-Aged Mice with Impaired Nrf2 Signaling. Front Physiol 2017; 8:268. [PMID: 28515695 PMCID: PMC5413495 DOI: 10.3389/fphys.2017.00268] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/11/2017] [Indexed: 12/18/2022] Open
Abstract
Nuclear factor erythroid 2 related factor 2 (Nrf2) signaling maintains the redox homeostasis and its activation is shown to suppress cardiac maladaptation. Earlier we reported that acute endurance exercise (2 days) evoked antioxidant cytoprotection in young WT animals but not in aged WT animals. However, the effect of repeated endurance exercise during biologic aging (WT) characterized by an inherent deterioration in Nrf2 signaling and pathological aging (pronounced oxidative susceptibility-Nrf2 absence) in the myocardium remains elusive. Thus, the purpose of our study was to determine the effect of chronic endurance exercise-induced cardiac adaptation in aged mice with and without Nrf2. Age-matched WT and Nrf2-null mice (Nrf2-/-) (>22 months) were subjected to 6 weeks chronic endurance exercise (25 meter/min, 12% grade). The myocardial redox status was assessed by expression of antioxidant defense genes and proteins along with immunochemical detection of DMPO-radical adduct, GSH-NEM, and total ubiquitination. Cardiac functions were assessed by echocardiography and electrocardiogram. At sedentary state, loss of Nrf2 resulted in significant downregulation of antioxidant gene expression (Nqo1, Ho1, Gclm, Cat, and Gst-α) with decreased GSH-NEM immuno-fluorescence signals. While Nrf2-/- mice subjected to CEE showed an either similar or more pronounced reduction in the transcript levels of Gclc, Nqo1, Gsr, and Gst-α in relation to WT littermates. In addition, the hearts of Nrf2-/- on CEE showed a substantial reduction in specific antioxidant proteins, G6PD and CAT along with decreased GSH, a pronounced increase in DMPO-adduct and the total ubiquitination levels. Further, CEE resulted in a significant upregulation of hypertrophy genes (Anf, Bnf, and β-Mhc) (p < 0.05) in the Nrf2-/- hearts in relation to WT mice. Moreover, the aged Nrf2-/- mice exhibited a higher degree of cardiac remodeling in association with a significant decrease in fractional shortening, pronounced ST segment, and J wave elevation upon CEE compared to age-matched WT littermates. In conclusion, our findings indicate that while the aged WT and Nrf2 knockout animals both exhibit hypertrophy after CEE, the older Nrf2 knockouts showed ventricular remodeling coupled with profound cardiac functional abnormalities and diastolic dysfunction.
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Affiliation(s)
- Gobinath Shanmugam
- Cardiac Aging and Redox Signaling Laboratory, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at BirminghamBirmingham, AL, USA
| | - Madhusudhanan Narasimhan
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences CenterLubbock, TX, USA
| | - Robbie L. Conley
- Cardiac Aging and Redox Signaling Laboratory, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at BirminghamBirmingham, AL, USA
| | - Thiagarajan Sairam
- PSG Center for Molecular Medicine and Therapeutics, PSG Institute of Medical Sciences and Research, PSG HospitalsCoimbatore, India
| | - Ashutosh Kumar
- Immunity, Inflammation, and Disease Laboratory, NIEHS/NIHRaleigh, NC, USA
| | - Ronald P. Mason
- Immunity, Inflammation, and Disease Laboratory, NIEHS/NIHRaleigh, NC, USA
| | - Ramalingam Sankaran
- PSG Center for Molecular Medicine and Therapeutics, PSG Institute of Medical Sciences and Research, PSG HospitalsCoimbatore, India
| | - John R. Hoidal
- Division of Pulmonary, Department of Medicine, University of Utah School of MedicineSalt Lake City, UT, USA
| | - Namakkal S. Rajasekaran
- Cardiac Aging and Redox Signaling Laboratory, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at BirminghamBirmingham, AL, USA
- PSG Center for Molecular Medicine and Therapeutics, PSG Institute of Medical Sciences and Research, PSG HospitalsCoimbatore, India
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah School of MedicineSalt Lake City, UT, USA
- Center for Free Radical Biology, University of Alabama at BirminghamBirmingham, AL, USA
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20
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Dwindling of cardio damaging effect of isoproterenol by Punica granatum L. peel extract involve activation of nitric oxide-mediated Nrf2/ARE signaling pathway and apoptosis inhibition. Nitric Oxide 2015; 50:105-113. [DOI: 10.1016/j.niox.2015.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/13/2015] [Accepted: 09/04/2015] [Indexed: 12/20/2022]
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21
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Kazama I. Burn-induced subepicardial injury in frog heart: a simple model mimicking ST segment changes in ischemic heart disease. J Vet Med Sci 2015; 78:313-6. [PMID: 26346747 PMCID: PMC4785125 DOI: 10.1292/jvms.15-0440] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
To mimic ischemic heart disease in humans, several animal models have been created, mainly in rodents by
surgically ligating their coronary arteries. In the present study, by simply inducing burn injuries on the
bullfrog heart, we reproduced abnormal ST segment changes in the electrocardiogram (ECG), mimicking those
observed in ischemic heart disease, such as acute myocardial infarction and angina pectoris. The “currents of
injury” created by a voltage gradient between the intact and damaged areas of the myocardium, negatively
deflected the ECG vector during the diastolic phase, making the ST segment appear elevated during the systolic
phase. This frog model of heart injury would be suitable to explain the mechanisms of ST segment changes
observed in ischemic heart disease.
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Affiliation(s)
- Itsuro Kazama
- Department of Physiology I, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8575, Japan
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22
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Tomala M, Miszalski-Jamka T, Zajdel W, Nawrotek B, Mazur W, Kereiakes DJ, Zmudka K. Angiographic result of index PCI determines the presence of right ventricular infarction in patients with acute inferior myocardial infarction. Int J Cardiovasc Imaging 2015. [PMID: 26208683 DOI: 10.1007/s10554-015-0717-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It is still a matter of debate which patients with acute inferior myocardial infarction are at increased risk of developing right ventricular (RV) myocardial infarction (RVMI). Cardiac magnetic resonance imaging (CMRI) with late enchancement (LE) is regarded as the gold standard for RVMI assessment. We aimed to determine the impact of initial angiographic status and salutary effect of primary percutaneous coronary intervention (PCI) on the presence of RVMI. In 114 patients undergoing emergency angiography and primary PCI of right coronary artery, 3-5 days after index PCI, LE CMRI was performed for assessing the RVMI. Forty-eight patients (42%) demonstrated RVMI. Multivariate regression analysis identified TIMI flow <2 in at least one RV branch after PCI as an independent angiographic predictor of RVMI [odds ratio (OR) 143.00, 95% confidence interval (CI) 18.10-1130.05, p < 0.001]. ST-segment elevation ≥ 1 mm in V4R was present in 83 (73%). TIMI flow <3 in at least one RV branch before PCI (OR 4.07, 95% CI 1.24-13.33, p = 0.02) was independent angiographic predictor of ST-segment elevation ≥ 1 mm in V4R. The only predictor of RVMI was TIMI flow <2 in at least one RV branch after PCI. ST-segment elevation ≥ 1 mm in V4R is caused by TIMI <3 flow in at least one RV branch before index PCI.
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Affiliation(s)
- Marek Tomala
- Department of Interventional Cardiology, John Paul II Hospital, Jagiellonian University Medical College, Prądnicka 80, 31-202, Kraków, Poland.
| | - Tomasz Miszalski-Jamka
- Department of Radiology and Imaging Diagnostics, John Paul II Hospital, Kraków, Poland.,Department of Clinical Radiology and Imaging Diagnostics, 4th Military Hospital, Wrocław, Poland
| | - Wojciech Zajdel
- Department of Interventional Cardiology, John Paul II Hospital, Jagiellonian University Medical College, Prądnicka 80, 31-202, Kraków, Poland
| | - Bartłomiej Nawrotek
- Department of Interventional Cardiology, John Paul II Hospital, Jagiellonian University Medical College, Prądnicka 80, 31-202, Kraków, Poland
| | - Wojciech Mazur
- The Lindner Center for Research and Education, The Christ Hospital Heart and Vascular Center, Cincinnati, OH, USA
| | - Dean J Kereiakes
- The Lindner Center for Research and Education, The Christ Hospital Heart and Vascular Center, Cincinnati, OH, USA
| | - Krzysztof Zmudka
- Department of Interventional Cardiology, John Paul II Hospital, Jagiellonian University Medical College, Prądnicka 80, 31-202, Kraków, Poland
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23
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Martí D, Mestre JL, Salido L, Esteban MJ, Casas E, Pey J, Sanmartín M, Hernández-Antolín R, Zamorano JL. Incidence, angiographic features and outcomes of patients presenting with subtle ST-elevation myocardial infarction. Am Heart J 2014; 168:884-90. [PMID: 25458652 DOI: 10.1016/j.ahj.2014.08.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 08/02/2014] [Indexed: 11/24/2022]
Abstract
BACKGROUND Borderline electrocardiograms represent a challenge in ST-segment elevation myocardial infarction (STEMI) management and are associated with inappropriate discharges and delays to intervention. OBJECTIVES To assess angiographic characteristics and outcomes of patients presenting with subtle ST-elevation (STE) myocardial infarction. METHODS A total of 504 consecutive patients with suspected STEMI treated by systematic primary percutaneous coronary intervention were prospectively included. Subtle STE was defined as a maximal preinterventional STE of 0.1 to 1 mm. Angiograms were interpreted by investigators unaware of the electrocardiographic data. RESULTS The proportion of patients with subtle STE was 18.3%, 86% of them presented with Thrombolysis In Myocardial Infarction flow grade 0/1 and 91% underwent percutaneous coronary intervention. Despite having smaller infarcts, subtle STE patients associated more frequent multivessel disease (57% vs 44%, P = .02) and larger delays to reperfusion. During a follow-up of 19.0 ± 4.9 months, the rates of death or reinfarction were similar among groups (10.0% vs 12.6%, P = .467). Subtle STE was not associated with better outcomes neither in univariate nor after adjustment in a multivariate analysis (adjusted hazard ratio 0.79, 95% CI 0.37-1.69, P = .546). CONCLUSIONS Subtle STEMI is frequent in clinical practice and is usually associated with acute total coronary occlusion. Therefore, it should be diagnosed and treated in the same expeditiously manner as marked STEMI.
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Prech M, Bartela E, Araszkiewicz A, Janus M, Kutrowska A, Urbanska L, Pyda M, Grajek S. Pre-angiography total ST-segment resolution is not a reliable predictor of an open infarct-related artery. Eur J Intern Med 2014; 25:826-30. [PMID: 25214008 DOI: 10.1016/j.ejim.2014.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 08/04/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND While the cutoffs of predictive value for ST-segment elevations resolution (STSR) following thrombolysis and/or primary PCI were well documented, the impact of pre-angiography STSR has not been established yet. OBJECTIVES The aim of this study is to assess prognostic utility of pre-angiography STSR to predict pre-procedural TIMI flow in the infarct-related artery (IRA) and infarct size in STEMI patients undergoing primary PCI. METHODS A prospective study was performed, including 310 patients, admitted within 12h of symptom onset and who underwent primary PCI. ST-segment elevations were measured in: (1) qualifying ECG, (2) ECG before angiography, and (3) ECG post PCI. STSR was defined as: total (≥70%), partial (between 70% and 30%) and none (<30%). Relationships between pre-angiography STSR, initial TIMI flow and troponin T level (TnT) were analyzed. RESULTS Pre-angiography STSR correlated with initial TIMI flow in the IRA (rS=0.619; p<0.001). Pre-angiography total STSR was observed in 23.2% patients. It was noted in 79.2% of patients with pre-procedural TIMI flow ≥2 and in 20.8% with TIMI flow ≤1 (p<0.001). Although the sensitivity of pre-angiography total STSR to detect pre-procedural TIMI flow ≥2 was 93%, its specificity was only 56% and the likelihood ratio was 2.1. Pre-angiography total STSR was associated with lower peak TnT level (2.2±2.5ng/ml vs. 6.4±5.0ng/ml, p<0.0001) when compared to the remaining patients. CONCLUSIONS 1. Pre-angiography STSR correlates with preprocedural TIMI flow. 2. The sensitivity of pre-angiography total STSR in detection of pre-procedural TIMI flow ≥2 is high, but low specificity of only 56% makes it an unreliable predictor of an open IRA.
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Affiliation(s)
- Marek Prech
- Department of Invasive Cardiology, Kiepury 45, 64-100 Leszno, Poland; I(st) Department of Cardiology, Poznan University of Medical Sciences, Dluga ½, 61-848 Poznan, Poland.
| | - Ewa Bartela
- Department of Invasive Cardiology, Kiepury 45, 64-100 Leszno, Poland.
| | - Aleksander Araszkiewicz
- I(st) Department of Cardiology, Poznan University of Medical Sciences, Dluga ½, 61-848 Poznan, Poland.
| | - Magdalena Janus
- I(st) Department of Cardiology, Poznan University of Medical Sciences, Dluga ½, 61-848 Poznan, Poland
| | - Aleksandra Kutrowska
- I(st) Department of Cardiology, Poznan University of Medical Sciences, Dluga ½, 61-848 Poznan, Poland
| | - Lidia Urbanska
- I(st) Department of Cardiology, Poznan University of Medical Sciences, Dluga ½, 61-848 Poznan, Poland
| | - Malgorzata Pyda
- I(st) Department of Cardiology, Poznan University of Medical Sciences, Dluga ½, 61-848 Poznan, Poland
| | - Stefan Grajek
- I(st) Department of Cardiology, Poznan University of Medical Sciences, Dluga ½, 61-848 Poznan, Poland.
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25
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Fernández-Cisnal A, Cid-Álvarez B, Álvarez-Álvarez B, Cubero-Gómez JM, Ocaranza-Sánchez R, López-Otero D, Souto-Castro P, Díaz de la Llera LS, Trillo-Nouche R, González-Juanatey JR. Real world comparison of the MGuard Stent versus the bare metal stent for ST elevation myocardial infarction (the REWARD-MI study). Catheter Cardiovasc Interv 2014; 85:E1-9. [PMID: 24905554 DOI: 10.1002/ccd.25563] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 05/13/2014] [Accepted: 05/25/2014] [Indexed: 11/10/2022]
Abstract
AIM The MGuard Stent (MGS) was designed to prevent distal embolization of thrombus and has been shown to improve microcirculation in ST-elevation myocardial infarction (STEMI). However, there are no real world data comparing it with the bare metal stent (BMS). The aim of this study is to determine the efficacy and safety of the MGS in STEMI in the real world compared to the BMS. METHODS AND RESULTS In total, 262 patients were included from a single centre, of which 35.9% had an MGS implanted. Two groups of 79 patients were established after propensity score matching, and they were similar in terms of baseline and periprocedural variables. The mean follow-up was 321 ± 12.94 days. There was no difference in mortality (7.6% in both groups), major adverse cardiac events (20.3% vs. 12.7%, P = 0.198), non-cardiac mortality, or non-fatal myocardial infarction (6.3% in both groups). Target lesion revascularization (TLR) was significantly higher in the MGS group (11.4% (9) vs. 1.3% (1) P < 0.01; RR 10.02 [1.23-81.16]). CONCLUSION Our study is the first to compare the MGS with the BMS in STEMI in the real world, and it also appears to confirm that although the MGS is a safe device in STEMI that is not associated with increased mortality, it is associated with a higher long-term TLR rate. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Agustín Fernández-Cisnal
- Haemodynamic and Interventional Cardiology Unit, University Hospital Virgen del Rocío, Seville, Spain
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26
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Di Diego JM, Antzelevitch C. Acute myocardial ischemia: cellular mechanisms underlying ST segment elevation. J Electrocardiol 2014; 47:486-90. [PMID: 24742586 DOI: 10.1016/j.jelectrocard.2014.02.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Indexed: 10/25/2022]
Abstract
The electrocardiogram (ECG) is an essential tool for the diagnosis of acute myocardial ischemia in the emergency department, as well as for that of an evolving acute myocardial infarction (AMI). Changes in the surface ECG in leads whose positive poles face the ischemic region are known to be related to injury currents flowing across the boundaries between the ischemic and the surrounding normal myocardium. Although experimental studies have also shown an endocardium to epicardium differential sensitivity to the effect of acute ischemia, the important contribution of this transmural heterogeneous response to the changes observed in the surface ECG is less appreciated by the clinical cardiologist. This review briefly discusses our current knowledge regarding the electrophysiology of the ischemic myocardium focusing primarily on the electrophysiologic changes underlying the ECG alterations observed at the onset of a transmural AMI.
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Bonomini MP, Arini PD, Gonzalez GE, Buchholz B, Valentinuzzi ME. The allometric model in chronic myocardial infarction. Theor Biol Med Model 2012; 9:15. [PMID: 22578057 PMCID: PMC3431992 DOI: 10.1186/1742-4682-9-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 05/11/2012] [Indexed: 11/10/2022] Open
Abstract
Background An allometric relationship between different electrocardiogram (ECG) parameters and infarcted ventricular mass was assessed in a myocardial infarction (MI) model in New Zealand rabbits. Methods A total of fifteen animals were used, out of which ten underwent left anterior descending coronary artery ligation to induce infarction (7–35% area). Myocardial infarction (MI) evolved and stabilized during a three month-period, after which, rabbits were sacrificed and the injured area was histologically confirmed. Right before sacrifice, ECGs were obtained to correlate several of its parameters to the infarcted mass. The latter was normalized after combining data from planimetry measurements and heart weight. The following ECG parameters were studied: RR and PR intervals, P-wave duration (PD), QRS duration (QRSD) and amplitude (QRSA), Q-wave (QA), R-wave (RA) and S-wave (SA) amplitudes, T-wave peak amplitude (TA), the interval from the peak to the end of the T-wave (TPE), ST-segment deviation (STA), QT interval (QT), corrected QT and JT intervals. Corrected QT was analyzed with different correction formulae, i.e., Bazett (QTB), Framingham (QTFRA), Fridericia (QTFRI), Hodge (QTHO) and Matsunaga (QTMA) and compared thereafter. The former variables and infarcted ventricular mass were then fitted to the allometric equation in terms of deviation from normality, in turn derived after ECGs in 5 healthy rabbits. Results Six variables (JT, QTB, QA, SA, TA and STA) presented statistical differences among leads. QT showed the best allometric fit (r = 0.78), followed by TA (r = 0.77), STA (r = 0.75), QTFRA (r = 0.72), TPE (r = 0.69), QTFRI (r = 0.68) and QTMA (r = 0.68). Corrected QT’s (QTFRA, QTFRI and QTMA) performed worse than the uncorrected counterpart (QT), the former scaling allometrically with similar goodness of fits. Conclusions QT, TA, STA and TPE could possibly be used to assess infarction extent in an old MI event through the allometric model as a first approach. Moreover, the TPE also produced a good allometric scaling, leading to the potential existence of promising allometric indexes to diagnose malignant arrhythmias.
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Affiliation(s)
- Maria P Bonomini
- Instituto de Ingeniería Biomédica, Facultad de Ingeniería, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Smrdel A, Jager F. Automatic classification of long-term ambulatory ECG records according to type of ischemic heart disease. Biomed Eng Online 2011; 10:107. [PMID: 22168286 PMCID: PMC3331855 DOI: 10.1186/1475-925x-10-107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 12/14/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Elevated transient ischemic ST segment episodes in the ambulatory electrocardiographic (AECG) records appear generally in patients with transmural ischemia (e. g. Prinzmetal's angina) while depressed ischemic episodes appear in patients with subendocardial ischemia (e. g. unstable or stable angina). Huge amount of AECG data necessitates automatic methods for analysis. We present an algorithm which determines type of transient ischemic episodes in the leads of records (elevations/depressions) and classifies AECG records according to type of ischemic heart disease (Prinzmetal's angina; coronary artery diseases excluding patients with Prinzmetal's angina; other heart diseases). METHODS The algorithm was developed using 24-hour AECG records of the Long Term ST Database (LTST DB). The algorithm robustly generates ST segment level function in each AECG lead of the records, and tracks time varying non-ischemic ST segment changes such as slow drifts and axis shifts to construct the ST segment reference function. The ST segment reference function is then subtracted from the ST segment level function to obtain the ST segment deviation function. Using the third statistical moment of the histogram of the ST segment deviation function, the algorithm determines deflections of leads according to type of ischemic episodes present (elevations, depressions), and then classifies records according to type of ischemic heart disease. RESULTS Using 74 records of the LTST DB (containing elevated or depressed ischemic episodes, mixed ischemic episodes, or no episodes), the algorithm correctly determined deflections of the majority of the leads of the records and correctly classified majority of the records with Prinzmetal's angina into the Prinzmetal's angina category (7 out of 8); majority of the records with other coronary artery diseases into the coronary artery diseases excluding patients with Prinzmetal's angina category (47 out of 55); and correctly classified one out of 11 records with other heart diseases into the other heart diseases category. CONCLUSIONS The developed algorithm is suitable for processing long AECG data, efficient, and correctly classified the majority of records of the LTST DB according to type of transient ischemic heart disease.
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Affiliation(s)
- Aleš Smrdel
- University of Ljubljana, Faculty of Computer and Information Science, Tržaška 25, 1000 Ljubljana, Slovenia.
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Varadan VK, Kumar PS, Oh S, Kegley L, Rai P. e-bra With Nanosensors for Real Time Cardiac Health Monitoring and Smartphone Communication. J Nanotechnol Eng Med 2011. [DOI: 10.1115/1.4003966] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Mortality due to cardiac related ailments has been consistently higher in women as compared with men since the early 1980s in the United States. Gender related differences in specificity of regular noninvasive diagnostic tools and the lack of a clear understanding of the effect of postmenopausal hormonal changes in women have been cited as the two main reasons for this disparity. Recent advances in secondary and tertiary diagnostic information extraction techniques from signals such as electrocardiogram (ECG) through heart rate variability (HRV) analysis and wavelet domain analysis techniques have revealed many differences in autonomic nervous-cardiovascular activity regulation, between men and women. Moreover, the diagnostic tests for cardiovascular diseases usually start upon the manifestation of chest pain or angina. At this stage, disease management is the only option as opposed to preventive treatments, which is also possible with early detection based on the diagnostic information extraction techniques as stated previously. In order to truly realize the potential of such techniques, continuous and long-term monitoring is an essential requirement. This, in turn, requires sensor systems to be seamlessly mounted on day to day clothing for women. This paper describes an e-bra platform for nanosensors toward cardiovascular monitoring. The sensors, nanomaterial, or textile based dry electrodes acquire electrocardiograph, which is sent to a textile mounted wireless module. A smartphone or a wireless Bluetooth enabled PC can receive these data and store or process the information as necessary. In this paper, we wirelessly acquire ECG from subjects with the e-bra and perform HRV analysis on a PC. The use of a Smartphone as a base station for receiving data offers the advantage of cellular network connectivity to internet and consequently cloud computing resources for more complex computations such as feature extraction and automatic diagnosis. To address this capability, we further propose a protocol for response to emergencies from both the cloud backend and the smartphone itself.
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Affiliation(s)
- Vijay K. Varadan
- Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701; Department of Neurosurgery, College of Medicine, Pennsylvania State University, Hershey Medical Center 500, University Drive, Hershey, PA 17033; Global Institute for Nanotechnology in Engineering and Medicine, 700 Research Center Boulevard, Fayetteville, AR 72701
| | - Prashanth S. Kumar
- Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701
| | - Sechang Oh
- Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701
| | - Lauren Kegley
- Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701
| | - Pratyush Rai
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR 72701
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Bonomini MP, Arini PD, Valentinuzzi ME. Probability of ventricular fibrillation: allometric model based on the ST deviation. Biomed Eng Online 2011; 10:2. [PMID: 21226961 PMCID: PMC3031271 DOI: 10.1186/1475-925x-10-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 01/13/2011] [Indexed: 12/03/2022] Open
Abstract
Background Allometry, in general biology, measures the relative growth of a part in relation to the whole living organism. Using reported clinical data, we apply this concept for evaluating the probability of ventricular fibrillation based on the electrocardiographic ST-segment deviation values. Methods Data collected by previous reports were used to fit an allometric model in order to estimate ventricular fibrillation probability. Patients presenting either with death, myocardial infarction or unstable angina were included to calculate such probability as, VFp = δ + β (ST), for three different ST deviations. The coefficients δ and β were obtained as the best fit to the clinical data extended over observational periods of 1, 6, 12 and 48 months from occurrence of the first reported chest pain accompanied by ST deviation. Results By application of the above equation in log-log representation, the fitting procedure produced the following overall coefficients: Average β = 0.46, with a maximum = 0.62 and a minimum = 0.42; Average δ = 1.28, with a maximum = 1.79 and a minimum = 0.92. For a 2 mm ST-deviation, the full range of predicted ventricular fibrillation probability extended from about 13% at 1 month up to 86% at 4 years after the original cardiac event. Conclusions These results, at least preliminarily, appear acceptable and still call for full clinical test. The model seems promising, especially if other parameters were taken into account, such as blood cardiac enzyme concentrations, ischemic or infarcted epicardial areas or ejection fraction. It is concluded, considering these results and a few references found in the literature, that the allometric model shows good predictive practical value to aid medical decisions.
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Affiliation(s)
- Maria P Bonomini
- Instituto de Ingeniería Biomédica, Universidad de Buenos Aires, Argentina
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Bouchard S, Jacquemet V, Vinet A. Automaticity in acute ischemia: bifurcation analysis of a human ventricular model. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:011911. [PMID: 21405717 DOI: 10.1103/physreve.83.011911] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 11/08/2010] [Indexed: 05/30/2023]
Abstract
Acute ischemia (restriction in blood supply to part of the heart as a result of myocardial infarction) induces major changes in the electrophysiological properties of the ventricular tissue. Extracellular potassium concentration ([K(o)(+)]) increases in the ischemic zone, leading to an elevation of the resting membrane potential that creates an "injury current" (I(S)) between the infarcted and the healthy zone. In addition, the lack of oxygen impairs the metabolic activity of the myocytes and decreases ATP production, thereby affecting ATP-sensitive potassium channels (I(Katp)). Frequent complications of myocardial infarction are tachycardia, fibrillation, and sudden cardiac death, but the mechanisms underlying their initiation are still debated. One hypothesis is that these arrhythmias may be triggered by abnormal automaticity. We investigated the effect of ischemia on myocyte automaticity by performing a comprehensive bifurcation analysis (fixed points, cycles, and their stability) of a human ventricular myocyte model [K. H. W. J. ten Tusscher and A. V. Panfilov, Am. J. Physiol. Heart Circ. Physiol. 291, H1088 (2006)] as a function of three ischemia-relevant parameters [K(o)(+)], I(S), and I(Katp). In this single-cell model, we found that automatic activity was possible only in the presence of an injury current. Changes in [K(o)(+)] and I(Katp) significantly altered the bifurcation structure of I(S), including the occurrence of early-after depolarization. The results provide a sound basis for studying higher-dimensional tissue structures representing an ischemic heart.
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Affiliation(s)
- Sylvain Bouchard
- Institut de Génie Biomédical, Department of Physiology, Faculty of Medicine, Université de Montréal and Centre de Recherche, Hôpital du Sacré-Coeur, Montréal, Canada,
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He F, Shaffer ML, Rodriguez-Colon S, Bixler EO, Vgontzas AN, Williams RW, Wu R, Cascio WE, Liao D. Acute effects of fine particulate air pollution on ST segment height: a longitudinal study. Environ Health 2010; 9:68. [PMID: 21059260 PMCID: PMC2989950 DOI: 10.1186/1476-069x-9-68] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 11/08/2010] [Indexed: 05/23/2023]
Abstract
BACKGROUND The mechanisms for the relationship between particulate air pollution and cardiac disease are not fully understood. Air pollution-induced myocardial ischemia is one of the potentially important mechanisms. METHODS We investigate the acute effects and the time course of fine particulate pollution (PM2.5) on myocardium ischemic injury as assessed by ST-segment height in a community-based sample of 106 healthy non-smokers. Twenty-four hour beat-to-beat electrocardiogram (ECG) data were obtained using a high resolution 12-lead Holter ECG system. After visually identifying and removing all the artifacts and arrhythmic beats, we calculated beat-to-beat ST-height from ten leads (inferior leads II, III, and aVF; anterior leads V3 and V4; septal leads V1 and V2; lateral leads I, V5, and V6,). Individual-level 24-hour real-time PM2.5 concentration was obtained by a continuous personal PM2.5 monitor. We then calculated, on a 30-minute basis, the corresponding time-of-the-day specific average exposure to PM2.5 for each participant. Distributed lag models under a linear mixed-effects models framework were used to assess the regression coefficients between 30-minute PM2.5 and ST-height measures from each lead; i.e., one lag indicates a 30-minute separation between the exposure and outcome. RESULTS The mean (SD) age was 56 (7.6) years, with 41% male and 74% white. The mean (SD) PM2.5 exposure was 14 (22) μg/m3. All inferior leads (II, III, and aVF) and two out of three lateral leads (I and V6), showed a significant association between higher PM2.5 levels and higher ST-height. Most of the adverse effects occurred within two hours after PM2.5 exposure. The multivariable adjusted regression coefficients β (95% CI) of the cumulative effect due to a 10 μg/m3 increase in Lag 0-4 PM2.5 on ST-I, II, III, aVF and ST-V6 were 0.29 (0.01-0.56) μV, 0.79 (0.20-1.39) μV, 0.52 (0.01-1.05) μV, 0.65 (0.11-1.19) μV, and 0.58 (0.07-1.09) μV, respectively, with all p < 0.05. CONCLUSIONS Increased PM2.5 concentration is associated with immediate increase in ST-segment height in inferior and lateral leads, generally within two hours. Such an acute effect of PM2.5 may contribute to increased potential for regional myocardial ischemic injury among healthy individuals.
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Affiliation(s)
- Fan He
- Department of Public Health Sciences, Penn State University College of Medicine, A210, 600 Centerview Dr. Suite 2200, Hershey, PA, 17033, USA
| | - Michele L Shaffer
- Department of Public Health Sciences, Penn State University College of Medicine, A210, 600 Centerview Dr. Suite 2200, Hershey, PA, 17033, USA
| | - Sol Rodriguez-Colon
- Department of Public Health Sciences, Penn State University College of Medicine, A210, 600 Centerview Dr. Suite 2200, Hershey, PA, 17033, USA
| | - Edward O Bixler
- Sleep Research & Treatment Center, Department of Psychiatry, Penn State University College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
| | - Alexandros N Vgontzas
- Sleep Research & Treatment Center, Department of Psychiatry, Penn State University College of Medicine, 500 University Dr., Hershey, PA, 17033, USA
| | - Ronald W Williams
- Exposure Measurements and Analysis Branch, Human Exposure and Atmospheric Sciences Division, U.S. EPA, MD-E205-04, Research Triangle Park, NC, 27711, USA
| | - Rongling Wu
- Department of Public Health Sciences, Penn State University College of Medicine, A210, 600 Centerview Dr. Suite 2200, Hershey, PA, 17033, USA
| | - Wayne E Cascio
- Department of Cardiovascular Sciences, Brody School of Medicine, and the East Carolina Heart Institute and East Carolina University, Ste C, 2315 Executive Cir, Greenville, NC, 27834, USA
| | - Duanping Liao
- Department of Public Health Sciences, Penn State University College of Medicine, A210, 600 Centerview Dr. Suite 2200, Hershey, PA, 17033, USA
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Franco LG, Fioravanti MCS, Damasceno AD, Borges AC, Soares LK, Rabelo RE, Silva LAFD. Assessment of serum enzymatic markers of cardiomyocytes injury in female dogs submitted to ketamine S(+), atropin and xylazine association. Acta Cir Bras 2010; 24:36-42. [PMID: 19169540 DOI: 10.1590/s0102-86502009000100008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Accepted: 11/19/2008] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To assessment of the aspartate aminotransferase (AST), creatine kinase (CK) and creatine kinase isoenzyme fraction MB (CK-MB) serum activity in female dogs anesthetized with ketamine S (+), atropine and xylazine in several associations. METHODS Twenty three healthy female dogs randomly distributed in four groups named as GI (n=6), GII (n=6), GIII (n=6) and GIV (n=5) were treated respectively with atropine and ketamine S(+) (0.04 mg/kg; 10 mg/kg); ketamine S(+) (10 mg/kg); atropine, xylazine and ketamine S(+) (0.04 mg/kg; 1.1 mg/kg; 10 mg/kg) and xylazine and ketamine S(+) (1.1 mg/kg; 10 mg/kg). AST, CK and CK-MB serum activity measurement before pre-medication (M0) and one, two, three, six, 12, 24, 36 hours after. RESULTS There was no significant change in AST, CK e CK-MB serum activity among groups. However, CK serum activity in relation to moments within the groups was increased in all groups over the time in spite of treatment, except GI. In relation to CK-MB activity, in the moments within the group, it was observed an increase compared to baseline in all groups. CONCLUSION Creatine kinase and creatine kinase fraction MB isoenzyme showed changes in their mean values remained higher than baseline for a longer time in GIII and GIV.
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Affiliation(s)
- Leandro Guimarães Franco
- Animal Science Post-Graduation Program, Veterinary College, Federal University of Goias, Goias, Brazil.
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Garcia-Rubira JC, Garcia-Borbolla R, Nuñez-Gil I, Manzano MC, Garcia-Romero MM, Fernandez-Ortiz A, Perez de Isla L, Macaya C. Distortion of the terminal portion of the QRS is predictor of shock after primary percutaneous coronary intervention for acute myocardial infarction. Int J Cardiol 2007; 130:241-5. [PMID: 18068246 DOI: 10.1016/j.ijcard.2007.08.051] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 07/02/2007] [Accepted: 08/03/2007] [Indexed: 11/29/2022]
Abstract
BACKGROUND Although invasive management of ST segment elevation myocardial infarction has improved the clinical outcome, cardiogenic shock (CS) remains an important issue. Our purpose was to asses the utility of the initial electrocardiogram in detecting patients who are at increased risk of CS after percutaneous coronary intervention for acute myocardial infarction. METHODS We evaluated 508 consecutive patients admitted in our Coronary Unit and treated by primary angioplasty within 12 h of an ST segment elevation myocardial infarction. Patients with cardiogenic shock at admission were excluded. Two groups were defined according to the presence of distortion of the terminal portion of the QRS in two or more adjacent leads (group 1) or the absence of this pattern (group 2). RESULTS There were 99 patients (20%) in group 1 and 409 (80%) in group 2. CS developed in 38 patients, 18 in group 1 (18%) and 20 in group 2 (5%), p<0.001. Seventeen patients died in hospital, 6 in group 1 (6%) and 11 in group 2 (3%), p 0.094. Multivariate analysis including clinical, electrocardiographic and angiographic variables showed distortion of the QRS as an independent predictor of cardiogenic shock (odds ratio 3.17, 95% confidence interval 1.44 to 6.96, p 0.004), together with Killip class at admission and TIMI 3 flow after revascularization. CONCLUSIONS Distortion of the terminal portion of the QRS complex is a strong predictor of cardiogenic shock in STEMI patients. Close hemodynamic monitoring should be warranted in patients showing this electrocardiographic pattern.
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Barnabei L, Marazìa S, De Caterina R. Receiver operating characteristic (ROC) curves and the definition of threshold levels to diagnose coronary artery disease on electrocardiographic stress testing. Part I: The use of ROC curves in diagnostic medicine and electrocardiographic markers of ischaemia. J Cardiovasc Med (Hagerstown) 2007; 8:873-81. [PMID: 17906471 DOI: 10.2459/jcm.0b013e3280126615] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A common problem in diagnostic medicine, when performing a diagnostic test, is to obtain an accurate discrimination between 'normal' cases and cases with disease, owing to the overlapping distributions of these populations. In clinical practice, it is exceedingly rare that a chosen cut point will achieve perfect discrimination between normal cases and those with disease, and one has to select the best compromise between sensitivity and specificity by comparing the diagnostic performance of different tests or diagnostic criteria available. Receiver operating characteristic (or receiver operator characteristic, ROC) curves allow systematic and intuitively appealing descriptions of the diagnostic performance of a test and a comparison of the performance of different tests or diagnostic criteria. This review will analyse the basic principles underlying ROC curves and their specific application to the choice of optimal parameters on exercise electrocardiographic (ECG) stress testing. Part I will focus on theoretical description and analysis along with reviewing the common problems related to the diagnosis of myocardial ischaemia by means of exercise ECG stress testing. Part II will be devoted to applying ROC curves to available diagnostic criteria through the analysis of ECG stress test parameters.
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Affiliation(s)
- Luca Barnabei
- Institute of Cardiology, G. d'Annunzio University, Ospedale San Camillo de Lellis, Via Forlanini 50, Chieti, Italy
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Dhote VV, Balaraman R. Gender specific effect of progesterone on myocardial ischemia/reperfusion injury in rats. Life Sci 2007; 81:188-97. [PMID: 17585947 DOI: 10.1016/j.lfs.2007.05.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 04/27/2007] [Accepted: 05/01/2007] [Indexed: 11/24/2022]
Abstract
The study was designed to investigate the effect of progesterone and its gender based variation on myocardial ischemia/reperfusion (I/R) injury in rats. Adult Sprague Dawley rats were divided into vehicle treated reperfusion injury group male (I/R-M), female (I/R-F), ovariectomised (I/R-OVR) and progesterone treatment (I/R-M+PG, I/R-F+PG, I/R-OVR+PG) groups, respectively. I/R injury was produced by occluding the left descending coronary artery (LCA) for 1 h and followed by re-opening for 1 h. Progesterone (2 mg kg(-1) i.p.) was administered 30 min after induction of ischemia. Hemodynamic parameters (+/-dp/dt, MAP), heart rate, ST-segment elevation and occurrence of ventricular tachycardia (VT) were measured during the I/R period. The myocardial infarct area, oxidative stress markers, activities of myeloperoxidase (MPO) and creatine kinase (CK) were determined after the experiment along with the assessment of the effect on apoptotic activity by using DNA fragmentation analysis. Histological observations were carried out on heart tissue. Treatment with progesterone significantly (P<0.05) reduced infarct area, lipid peroxidation (LPO) level and activity of MPO in females (I/R-F+PG) as compared to ischemic females (I/R-F). Progesterone significantly (P<0.001, P<0.05) inhibited serum CK activity and incidences of VT in female rats. Superoxide dismutase (SOD) activity, reduced glutathione (GSH) levels were significantly elevated (P<0.05) in I/R-F+PG group. Internucleosomal DNA fragmentation was less in I/R-F+PG group when compared to I/R-F group. The ischemic male and ovariectomised (I/R-M and I/R-OVR) counterparts did not show any significant change after progesterone treatment. In conclusion, the cardioprotective effect of progesterone on myocardial I/R injury induced damage is based on gender of the animal. The protective effect could be mediated by attenuation of inflammation and its possible interaction with endogenous estrogen.
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Affiliation(s)
- Vipin V Dhote
- Pharmacy Department, The M.S. University of Baroda, Faculty of Technology and Engineering, Kalabhavan, Vadodara, 390001, Gujarat, India
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Carrabba N, Parodi G, Valenti R, Shehu M, Migliorini A, Santoro GM, Antoniucci D. Significance of additional ST segment elevation in patients with no reflow after angioplasty for acute myocardial infarction. J Am Soc Echocardiogr 2007; 20:262-9. [PMID: 17336752 DOI: 10.1016/j.echo.2006.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Indexed: 11/17/2022]
Abstract
OBJECTIVES We sought to evaluate the incidence, timing, and clinical significance of additional increase in ST segment elevation (ST-SE) in patients showing no reflow after angioplasty for acute myocardial infarction. METHODS We studied 26 patients with acute myocardial infarction showing myocardial contrast echocardiography no reflow after successful angioplasty. Baseline and 6-month 2-dimensional echocardiograms were obtained in 21 surviving patients. RESULTS After angioplasty, 13 patients showed greater than 30% additional increase in ST-SE (group 1), whereas 13 did not (group 2). Baseline clinical, echographic, and angiographic characteristics, and 6-month patency and restenosis rate, were similar between the two groups. From baseline to 6 months, a similar global and regional systolic function was found between the two groups, whereas a higher increase in left ventricular end-diastolic volume occurred in group 1 (135 +/- 45 vs 168 +/- 42 mL, P = .033). The additional increase in ST-SE was not associated with more severe microvascular damage (myocardial contrast echocardiography score index: 0.14 +/- 0.26 vs 0.22 +/- 0.27), higher peak creatine kinase value (4888 +/- 2533 vs 3109 +/- 2055 U/L, P = .061), higher incidence of left ventricular remodeling (73% vs 60%, P = .537), or worse outcome (26 +/- 24 months) such as death (15% vs 23%, P = .619), hospitalization for heart failure (8% vs 23%, P = .277), or reinfarction (8% vs 0%, P = .308). CONCLUSIONS Our data show that in patients showing no reflow after angioplasty a transient additional increase in ST-SE occurs in half of patients. The prognostic value of additional increase in ST-SE remains uncertain in the era of primary angioplasty.
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Liu CB, Li RD. Electrocardiogram and heart rate in response to temperature acclimation in three representative vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2005; 142:416-21. [PMID: 16249112 DOI: 10.1016/j.cbpa.2005.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 08/30/2005] [Accepted: 09/09/2005] [Indexed: 10/25/2022]
Abstract
Comparisons of electrocardiogram (ECG) and heart rate characteristics of three representative species in response to temperature acclimation were studied. In toad (Bufo raddei), T wave had positive, negative and flat patterns, which was different from positive in lizard (Eremias multiocellata), blunt and broad in bird (Alectories magna). The duration of P-R interval, Q-T interval and QRS complex interval reduced with increasing temperature in toad, but the P-R and T-P intervals were affected mostly, the QRS and R-T intervals were relatively less affected in lizard. In the bird, the voltage of P, S and T wave scarcely changed, R wave increased slightly with temperature going up in the thermal neutral zone (20-35 degrees C), T and S waves tended to increase and P-S and S-T intervals shortened when temperature went below the neutral zone. Heart rate was high and relatively steady in bird, but changed linearly in relation to temperature in toad and lizard. The increasing of heart rate with temperature was mainly caused by the T-P interval shortened in lizard, but P-S and S-T intervals shortened in bird. Comparisons of ECG and heart rate characteristics of three representative species in response to temperature acclimation reflected phylogenetically based constraints on pacemaker rates, oxygen supply and modulatory mechanisms.
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Affiliation(s)
- Chong-Bin Liu
- School of Life Sciences, Lanzhou University, Gansu, Lanzhou 730000, PR China
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Stanley WC. Myocardial energy metabolism during ischemia and the mechanisms of metabolic therapies. J Cardiovasc Pharmacol Ther 2005; 9 Suppl 1:S31-45. [PMID: 15378130 DOI: 10.1177/107424840400900104] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The primary effect of ischemia is reduced aerobic adenosine triphosphate (ATP) formation in mitochondria. This triggers accelerated glycolysis and reduced cell pH, Ca(2+) accumulation, K(+) efflux, adenosine formation, and the clinical signs of ischemia: chest pain and a shift in the ST segment. Traditional therapies for angina are aimed at either decreasing the need for ATP by suppressing heart rate, blood pressure, and cardiac contractility, or at increasing oxygen delivery to the mitochondria, or both. An additional approach to treating angina is to suppress myocardial fatty acid oxidation, increase pyruvate oxidation, and reduce anaerobic glycolysis. High fatty acid levels result in oxygen wasting and inhibit the oxidation of pyruvate in the mitochondria. In experimental models, the partial inhibition of myocardial fatty acid oxidation with agents such as oxfenicine, ranolazine, and trimetazidine stimulates glucose oxidation and reduces lactate production during ischemia. Clinical studies demonstrate that this approach is as effective as traditional hemodynamic therapies at improving exercise tolerance and reducing the frequency of angina. Moreover, because these agents do not suppress heart rate, blood pressure, or contractility, they are effective as add-on therapy to Ca(2+)-channel and beta-adrenergic receptor antagonists.
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Affiliation(s)
- William C Stanley
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
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Abstract
We report a case of a 58-year-old man with Shoshin beriberi who demonstrated ST-segment elevation and myocardial damage without coronary artery stenosis. The patient subsequently recovered with thiamine treatment. We conclude that it is important to consider Shoshin beriberi as part of the differential diagnosis in patients with shock and ST-segment elevation.
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Affiliation(s)
- Hiroaki Kawano
- Department of Cardiovascular Medicine, Course of Medical and Dental Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto
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Sorajja P, Gersh BJ, Costantini C, McLaughlin MG, Zimetbaum P, Cox DA, Garcia E, Tcheng JE, Mehran R, Lansky AJ, Kandzari DE, Grines CL, Stone GW. Combined prognostic utility of ST-segment recovery and myocardial blush after primary percutaneous coronary intervention in acute myocardial infarction. Eur Heart J 2005; 26:667-74. [PMID: 15734768 DOI: 10.1093/eurheartj/ehi167] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS ST-segment recovery (SigmaSTR) and myocardial blush (MB) evaluate different elements of microcirculatory integrity after reperfusion therapy in acute myocardial infarction (AMI). We sought to determine whether the combination of SigmaSTR and MB after primary percutaneous coronary intervention (PCI) in AMI has greater prognostic utility than either measure alone. METHODS AND RESULTS The 30 days and 1 year clinical outcomes of 456 patients were assessed as a function of SigmaSTR and MB after primary PCI from the CADILLAC trial. SigmaSTR and MB were concordant (> or =70% SigmaSTR and MB grade 2/3 or <70% SigmaSTR and MB grade 0/1) in 60.1% of patients and discordant in 39.9% of patients. The greatest survival was observed among patients with complete SigmaSTR (> or =70%) and MB grade 2/3 in whom the cumulative rates of death at 30 days and 1 year were 0.6 and 1.2%, respectively. Poorest survival was observed among patients with incomplete SigmaSTR (<70%) and reduced MB (grade 0/1), in whom 30 days and 1 year rates of death were 8.3 and 10.1%, respectively. Intermediate outcomes were present in patients with discordant MB and SigmaSTR. By multivariable analysis, however, SigmaSTR was an independent correlate of survival at 30 days and 1 year (P=0.05 and 0.01, respectively), whereas MB was no longer predictive (P=0.38 and 0.72, respectively). CONCLUSION SigmaSTR and MB are not infrequently discordant after primary PCI. By univariate analysis, both measures of reperfusion success strongly correlate with survival and assessment of both yields incremental prognostic information beyond either measure alone. By multivariable analysis, however, SigmaSTR is the stronger prognostic variable.
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Affiliation(s)
- Paul Sorajja
- The Mayo Clinic and Mayo Foundation, Rochester, MN, USA
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Welin AK, Blad S, Hagberg H, Rosén KG, Kjellmer I, Mallard C. Electrocardiographic changes following umbilical cord occlusion in the midgestation fetal sheep. Acta Obstet Gynecol Scand 2005; 84:122-8. [PMID: 15683370 DOI: 10.1111/j.0001-6349.2005.00594.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Clinical studies show that analysis of the fetal electrocardiographic (FECG) ST waveform at term gives important information on the myocardial response to intrapartum asphyxia. However, it is not known whether the preterm fetus responds in a similar fashion. The objective of the present study was to evaluate the FECGST response to umbilical cord occlusion in the preterm fetal sheep. METHODS Fetal sheep at midgestation were subjected to 25 min umbilical cord occlusion (n = 7) and compared to controls (n = 5). Changes in the FECGST waveform were recorded together with arterial blood pressure, heart rate, and acid base status during the occlusion and for 3 days afterward. RESULTS Umbilical cord occlusion resulted in immediate bradycardia (control: 187 +/- 7 bpm versus occlusion: 102 +/- 7 bpm), hypertension (control: 43.2 +/- 1.1 mmHg versus occlusion: 59.8 +/- 2.2 mmHg), and an initial increase in the T/QRS ratio (control: 0.10 +/- 0.02 versus occlusion: 0.60 +/- 0.10, P < 0.001), followed by hypotension (21.7 +/- 1.2 mmHg), normalization of the T/QRS ratio, and in some cases the development of negative T waves toward the end of the occlusion. CONCLUSIONS These studies show that the midgestation fetal sheep has the capacity to react to umbilical cord occlusion with a significant increase in the amplitude of the ST waveform together with an augmentation of blood pressure, which then subsides as the occlusion continues. The appearance of negative ST segment appears to signify significant cardiac dysfunction. The characteristic progression of ST-waveform changes in response to umbilical cord occlusion in midgestation fetal sheep, suggests that monitoring the ST waveform may contribute clinically important information also in the preterm individual.
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Affiliation(s)
- Anna-Karin Welin
- Department of Obstetrics and Gynecology, Perinatal Center, University of Göteborg, SE-416 85 Göteborg, Sweden.
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Ortega-Carnicer J. Giant R wave, convex ST-segment elevation, and negative T wave during exercise treadmill test. J Electrocardiol 2004; 37:231-6. [PMID: 15286937 DOI: 10.1016/j.jelectrocard.2004.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The giant R wave syndrome is characterized by giant R wave accompanied by widening of the QRS complex, marked ST segment elevation, QRS axis deviation, and the formation of monophasic QRS-ST complex with obliteration of S wave in leads facing the ischemic zone. This report describes a 65-year-old-man with variant angina who had a transient giant R wave syndrome during an exercise treadmill test. Initially, at peak exercise, there was a convex ST segment elevation ending in a negative T wave in the same (inferior) leads which showed giant R waves. Later, in the recovery period and coinciding with an amelioration of myocardial ischemia, there was a less marked increase of R wave amplitude associated with concave ST segment elevation and positive T wave in the inferolateral leads. Subsequently, a ST segment depression in the inferolateral leads preceded the ECG normalization. The patient had also a concave ST segment elevation and positive T wave in inferolateral leads during a spontaneous episode of variant angina at rest. An emergency coronary arteriography showed a dominant right coronary artery with an 80% and a 75% diameter stenosis of the middle and distal segment, respectively; the other arteries and left ventriculogram were normal. The underlying mechanisms of the different shapes of ST segment elevation and T waveform in the setting of acute transmural myocardial ischemia are discussed.
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Kumar K, Nguyen K, Waxman S, Nearing BD, Wellenius GA, Zhao SX, Verrier RL. Potent antifibrillatory effects of intrapericardial nitroglycerin in the ischemic porcine heart. J Am Coll Cardiol 2003; 41:1831-7. [PMID: 12767672 DOI: 10.1016/s0735-1097(03)00340-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES We investigated the antiarrhythmic effects of intrapericardial nitroglycerin (NTG) during acute myocardial ischemia in the porcine heart. BACKGROUND Nitroglycerin is a nitric oxide donor that exerts potent effects on the cardiovascular system. Intrapericardial administration allows investigation of pharmacologic actions on cardiac tissue in an in vivo system while minimizing the confounding influences of systemic effects. METHODS In 29 closed-chest pigs, myocardial ischemia was induced by intraluminal balloon occlusion of the left anterior descending coronary artery. Arrhythmia incidence was monitored during 5-min balloon inflations performed without drug and at 15, 45, 75, and 105 min after NTG (4,000 microg bolus) administered by percutaneous transatrial access into the pericardial space. Electrocardiograms were monitored for ischemia-induced T-wave alternans (TWA), a marker of electrical instability. The antiadrenergic potential of NTG was investigated by examining the drug's suppression of dobutamine-induced increase in myocardial contractility. RESULTS Control coronary artery occlusion provoked ventricular fibrillation (VF) in all animals. Intrapericardial NTG suppressed VF at 45 min in all six pigs (p < 0.05) and reduced TWA across a parallel time course (from 459.1 +/- 144.4 microV before drug to 42.22 +/- 13.96 microV at 45 min, p = 0.047). The antifibrillatory effect occurred as early as 15 min and persisted for up to 75 min. Augmentation of maximum of the first time derivative of left ventricular pressure by dobutamine was blunted by intrapericardial NTG (from 3,999 +/- 196 mm Hg/s before NTG to 3,543 +/- 220 mm Hg/s at 15 min, p = 0.012). CONCLUSIONS Intrapericardial NTG exerts a robust antifibrillatory action. Potential mechanisms include reduction in electrical instability and blunting of adrenergic effects.
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Affiliation(s)
- Kapil Kumar
- Harvard Medical School, Boston, Massachusetts, USA
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Seino S, Miki T. Physiological and pathophysiological roles of ATP-sensitive K+ channels. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2003; 81:133-76. [PMID: 12565699 DOI: 10.1016/s0079-6107(02)00053-6] [Citation(s) in RCA: 374] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
ATP-sensitive potassium (K(ATP)) channels are present in many tissues, including pancreatic islet cells, heart, skeletal muscle, vascular smooth muscle, and brain, in which they couple the cell metabolic state to its membrane potential, playing a crucial role in various cellular functions. The K(ATP) channel is a hetero-octamer comprising two subunits: the pore-forming subunit Kir6.x (Kir6.1 or Kir6.2) and the regulatory subunit sulfonylurea receptor SUR (SUR1 or SUR2). Kir6.x belongs to the inward rectifier K(+) channel family; SUR belongs to the ATP-binding cassette protein superfamily. Heterologous expression of differing combinations of Kir6.1 or Kir6.2 and SUR1 or SUR2 variant (SUR2A or SUR2B) reconstitute different types of K(ATP) channels with distinct electrophysiological properties and nucleotide and pharmacological sensitivities corresponding to the various K(ATP) channels in native tissues. The physiological and pathophysiological roles of K(ATP) channels have been studied primarily using K(ATP) channel blockers and K(+) channel openers, but there is no direct evidence on the role of the K(ATP) channels in many important cellular responses. In addition to the analyses of naturally occurring mutations of the genes in humans, determination of the phenotypes of mice generated by genetic manipulation has been successful in clarifying the function of various gene products. Recently, various genetically engineered mice, including mice lacking K(ATP) channels (knockout mice) and mice expressing various mutant K(ATP) channels (transgenic mice), have been generated. In this review, we focus on the physiological and pathophysiological roles of K(ATP) channels learned from genetic manipulation of mice and naturally occurring mutations in humans.
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Affiliation(s)
- Susumu Seino
- Department of Cellular and Molecular Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana Chuo-ku, Chiba 260-8760, Japan.
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Abstract
Body surface electrocardiograms and electrograms recorded from the surfaces of the heart are the basis for diagnosis and treatment of cardiac electrophysiological disorders and arrhythmias. Given recent advances in understanding the molecular mechanisms of arrhythmia, it is important to relate these electrocardiographic waveforms to cellular electrophysiological processes. This modeling study establishes the following principles: (1) voltage gradients created by heterogeneities of the slow-delayed rectifier (I(Ks)) and transient outward (I(to)) potassium current inscribe the T wave and J wave, respectively; T-wave polarity and width are strongly influenced by the degree of intercellular coupling through gap-junctions. (2) Changes in [K+]o modulate the T wave through their effect on the rapid-delayed rectifier, I(Kr). (3) Alterations of I(Ks), I(Kr), and I(Na) (fast sodium current) in long-QT syndrome (LQT1, LQT2, and LQT3, respectively) are reflected in characteristic QT-interval and T-wave changes; LQT1 prolongs QT without widening the T wave. (4) Accelerated inactivation of I(Na) on the background of large epicardial I(to) results in ST elevation (Brugada phenotype) that reflects the degree of severity. (5) Activation of the ATP-sensitive potassium current, I(K(ATP)), is sufficient to cause ST elevation during acute ischemia. These principles provide a mechanistic cellular basis for interpretation of electrocardiographic waveforms.
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Affiliation(s)
- Kazutaka Gima
- Cardiac Bioelectricity Research and Training Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7207, USA
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Abstract
ST elevation is a classical hallmark of acute transmural myocardial ischemia. Indeed, ST elevation is the major clinical criterion for committing patients with chest pain to emergent coronary revascularization. Despite its clinical importance, the mechanism of ST elevation remains unclear. Various studies have suggested that activation of sarcolemmal ATP-sensitive potassium (K(ATP)) channels by ischemic ATP depletion may play a role, but little direct evidence is available. We studied mice with homozygous knockout (KO) of the Kir6.2 gene, which encodes the pore-forming subunit of cardiac surface K(ATP) channels. Patch-clamp studies in cardiomyocytes confirmed that surface K(ATP) current was indeed absent in KO, but robust in cells from wild-type mice (WT). We then measured continuous electrocardiograms in anesthetized adult mice before and after open-chest ligation of the left anterior descending artery (LAD). Whereas ST elevation was readily evident in WT after LAD ligation, it was markedly suppressed in KO. Such qualitative differences persisted for the rest of the 60-minute observation period of ischemia. In support of the concept that K(ATP) channels are responsible for ST elevation, the surface K(ATP)channel blocker HMR1098 (5 mg/kg IP) suppressed early ST elevation in WT. Thus, the opening of sarcolemmal K(ATP)channels underlies ST elevation during ischemia. These data are the first to link a specific gene product with a common electrocardiographic phenomenon.
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Affiliation(s)
- R A Li
- Institute of Molecular Cardiobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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