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Vardas EP, Theofilis P, Oikonomou E, Vardas PE, Tousoulis D. MicroRNAs in Atrial Fibrillation: Mechanisms, Vascular Implications, and Therapeutic Potential. Biomedicines 2024; 12:811. [PMID: 38672166 PMCID: PMC11048414 DOI: 10.3390/biomedicines12040811] [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: 02/29/2024] [Revised: 03/27/2024] [Accepted: 04/03/2024] [Indexed: 04/28/2024] Open
Abstract
Atrial fibrillation (AFib), the most prevalent arrhythmia in clinical practice, presents a growing global health concern, particularly with the aging population, as it is associated with devastating complications and an impaired quality of life. Its pathophysiology is multifactorial, including the pathways of fibrosis, inflammation, and oxidative stress. MicroRNAs (miRNAs), small non-coding RNA molecules, have emerged as substantial contributors in AFib pathophysiology, by affecting those pathways. In this review, we explore the intricate relationship between miRNAs and the aforementioned aspects of AFib, shedding light on the molecular pathways as well as the potential diagnostic applications. Recent evidence also suggests a possible role of miRNA therapeutics in maintenance of sinus rhythm via the antagonism of miR-1 and miR-328, or the pharmacological upregulation of miR-27b and miR-223-3p. Unraveling the crosstalk between specific miRNA profiles and genetic predispositions may pave the way for personalized therapeutic approaches, setting the tone for precision medicine in atrial fibrillation.
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Affiliation(s)
- Emmanouil P. Vardas
- 1st Cardiology Department, General Hospital of Athens “Hippokration”, University of Athens Medical School, 11528 Athens, Greece; (E.P.V.); (P.T.)
- Department of Cardiology, General Hospital of Athens “G. Gennimatas”, 11527 Athens, Greece
| | - Panagiotis Theofilis
- 1st Cardiology Department, General Hospital of Athens “Hippokration”, University of Athens Medical School, 11528 Athens, Greece; (E.P.V.); (P.T.)
| | - Evangelos Oikonomou
- 3rd Cardiology Department, Sotiria Regional Hospital for Chest Diseases, University of Athens Medical School, 11527 Athens, Greece;
| | - Panos E. Vardas
- Biomedical Research Foundation Academy of Athens, Heart Sector, Hygeia Hospitals Group, Attica, 15123 Athens, Greece;
| | - Dimitris Tousoulis
- 1st Cardiology Department, General Hospital of Athens “Hippokration”, University of Athens Medical School, 11528 Athens, Greece; (E.P.V.); (P.T.)
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Parasympathetic and Sympathetic Monitoring Identifies Earliest Signs of Autonomic Neuropathy. NEUROSCI 2022. [DOI: 10.3390/neurosci3030030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The progression of autonomic dysfunction from peripheral autonomic neuropathy (PAN) to cardiovascular autonomic neuropathy, including diabetic autonomic neuropathy and advanced autonomic dysfunction, increases morbidity and mortality risks. PAN is the earliest stage of autonomic neuropathy. It typically involves small fiber disorder and often is an early component. Small fiber disorder (SFD) is an inflammation of the C-nerve fibers. Currently, the most universally utilized diagnostic test for SFD as an indicator of PAN is galvanic skin response (GSR), as it is less invasive than skin biopsy. It is important to correlate a patient’s symptoms with several autonomic diagnostic tests so as not to treat patients with normal findings unnecessarily. At a large suburban northeastern United States (Sicklerville, NJ) autonomic clinic, 340 consecutive patients were tested with parasympathetic and sympathetic (P&S) monitoring (P&S Monitor 4.0; Physio PS, Inc., Atlanta, GA, USA) with cardiorespiratory analyses, and TMFlow (Omron Corp., Hoffman Estates, Chicago, IL, USA) with LD Technology sudomotor test (SweatC™). This is a prospective, nonrandomized, observational, population study. All patients were less than 60 y/o and were consecutively tested, analyzed and followed from February 2018 through May 2020. P&S Monitoring is based on cardiorespiratory analyses and SweatC™ sudomotor testing is based on GSR. Overall, regardless of the stage of autonomic neuropathy, SweatC™ and P&S Monitoring are in concordance for 306/340 (90.0%) of patients from this cohort. The result is an 89.4% negative predictive value of any P&S disorder if the sudomotor GSR test is negative and a positive predictive value of 90.4% if the sudomotor testing is positive. In detecting early stages of autonomic neuropathy, P&S Monitoring was equivalent to sudomotor testing with high sensitivity and specificity and high negative and positive predictive values. Therefore, either testing modality may be used to risk stratify patients with suspected autonomic dysfunction, including the earliest stages of PAN and SFD. Moreover, when these testing modalities were normal, their high negative predictive values aid in excluding an underlying autonomic nervous system dysfunction.
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Yang CH, Liu HT, Lee HL, Lin FC, Chou CC. Left atrial booster-pump function as a predictive parameter for atrial fibrillation in patients with severely dilated left atrium. Quant Imaging Med Surg 2022; 12:2523-2534. [PMID: 35371928 PMCID: PMC8923837 DOI: 10.21037/qims-21-954] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 01/12/2022] [Indexed: 03/22/2024]
Abstract
BACKGROUND Left atrial (LA) dimension ≥50 mm had approximately four times the risk of developing atrial fibrillation (AF). The aim of this study was to investigate whether the application of clinical and echocardiographic parameters could differentiate between the patients having severely dilated left atrium with and without AF. METHODS This retrospective cross-sectional study enrolled consecutive patients with LA dimension ≥50 mm and divided them into three groups: no AF (no-AF), paroxysmal AF (PAF) and non-paroxysmal AF (non-PAF) groups. For PAF and non-PAF groups, all patients underwent radiofrequency ablation, and the echocardiographic parameters were obtained on the next day after ablation. RESULTS Our study population comprised 160 patients, including 80, 53, and 27 patients in the non-AF, PAF and non-PAF groups, respectively. The no-AF group had a significantly higher body mass index (kg/m2) (29.31±6.27, 27.58±4.12 and 26.57±2.81, P=0.01), and a higher prevalence of diabetes mellitus (DM) [31 (38.80%), 13 (25.00%) and 4 (14.80%), P=0.01] and hypertension [67 (83.80%), 34 (65.40%), and 19 (70.40%), P=0.04], but a lower prevalence of rheumatic heart disease (RHD) [3 (3.80%), 6 (11.50%) and 5 (18.50%), P=0.02] and sick sinus syndrome [0 (0.00%), 6 (11.50%) and 4 (14.80%), P=0.045]. Echocardiographic studies showed that the non-AF group had significantly smaller LA minimal volume index (24.89±9.74, 34.06±19.38 and 42.83±17.44 mL/m2, P<0.01), higher LA emptying fraction (51.99%±13.97%, 38.40%±15.96% and 33.89%±10.73%, P<0.01), longitudinal strain (23.87%±7.72%, 17.11%±8.52% and 12.38%±4.28%, P<0.01) and strain rate than the AF groups. The multivariate analysis showed that the late diastolic component of LA strain rate was the only independent factor associated with the presence of AF (odds ratio, 21.69; 95% CI, 9.77-48.13, P<0.01). CONCLUSIONS LA function plays an important role in the absence of AF in patients with LA dimension ≥50 mm; the late diastolic component of LA strain rate was the only independent variable on multivariate analysis.
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Affiliation(s)
- Chia-Hung Yang
- Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan
- Department of Internal Medicine, New Taipei Municipal TuCheng Hospital, New Taipei
| | - Hao-Tien Liu
- Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan
| | - Hui-Ling Lee
- Department of Anesthesia, Chang Gung Memorial Hospital, Taipei Branch, Taipei
| | - Fen-Chiung Lin
- Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan
| | - Chung-Chuan Chou
- Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan
- Chang Gung University College of Medicine, Taoyuan
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Rao LY, Mao Y, Huang K, Li YS, Shu YW. Relationship between Atrial Tissue Remodeling and ECG Features in Atrial Fibrillation. Curr Med Sci 2019; 39:541-545. [PMID: 31346988 DOI: 10.1007/s11596-019-2071-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 06/01/2019] [Indexed: 11/26/2022]
Abstract
The difference in the atrial organizational structure between patients with atrial fibrillation (AF) and those with sinus rhythm was investigated. In order to analyze the rationality in explaining the electrocardiogram (ECG) characteristics of AF with statistics data or tissue remodeling model, and the logical relationship between the hypothesis of pulmonary veins (PV) muscle sleeves and that of multi wavelets in mechanism of AF, we examined the expression of collagen volume fraction of type I (CVF-I) with picrosirius red staining, connexin 40 (Cx40) by immunohistochemistry, and intercalated disc (ID) using transmission electron microscope in atrial tissue. The results showed that there was significant difference in the expression of CVF-I (t=3.827, P<0.01), Cx40 (t=4.21, P<0.01), and groups of the ID that keeping the electrical transmission and atrial electrical coupling synchronization (t=15.116, P<0.001), but no significant difference was found in total IDs (t=0.611, P=0.543) between patients with AF and those with sinus rhythm. The quantitative differences in the tissue remodeling could not explain the ECG characteristics of AF. The number of normal IDs and abnormal distribution are the structural basis to trigger and maintain atrial electrical remodeling, and induce and maintain AF. Such histological reconstruction supports the hypothesis of multi wavelets and can also explain ECG features.
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Affiliation(s)
- Li-Ya Rao
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yi Mao
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Kun Huang
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yu-Shu Li
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yan-Wen Shu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Henry AD, MacQuaide N, Burton FL, Rankin AC, Rowan EG, Drummond RM. Spontaneous Ca 2+ transients in rat pulmonary vein cardiomyocytes are increased in frequency and become more synchronous following electrical stimulation. Cell Calcium 2018; 76:36-47. [PMID: 30253263 DOI: 10.1016/j.ceca.2018.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 08/09/2018] [Accepted: 09/02/2018] [Indexed: 12/13/2022]
Abstract
The pulmonary veins have an external sleeve of cardiomyocytes that are a widely recognised source of ectopic electrical activity that can lead to atrial fibrillation. Although the mechanisms behind this activity are currently unknown, changes in intracellular calcium (Ca2+) signalling are purported to play a role. Therefore, the intracellular Ca2+ concentration was monitored in the pulmonary vein using fluo-4 and epifluorescence microscopy. Electrical field stimulation evoked a synchronous rise in Ca2+ in neighbouring cardiomyocytes; asynchronous spontaneous Ca2+ transients between electrical stimuli were also present. Immediately following termination of electrical field stimulation at 3 Hz or greater, the frequency of the spontaneous Ca2+ transients was increased from 0.45 ± 0.06 Hz under basal conditions to between 0.59 ± 0.05 and 0.65 ± 0.06 Hz (P < 0.001). Increasing the extracellular Ca2+ concentration enhanced this effect, with the frequency of spontaneous Ca2+ transients increasing from 0.45 ± 0.05 Hz to between 0.75 ± 0.06 and 0.94 ± 0.09 Hz after electrical stimulation at 3 to 9 Hz (P < 0.001), and this was accompanied by a significant increase in the velocity of Ca2+ transients that manifested as waves. Moreover, in the presence of high extracellular Ca2+, the spontaneous Ca2+ transients occurred more synchronously in the initial few seconds following electrical stimulation. The ryanodine receptors, which are the source of spontaneous Ca2+ transients in pulmonary vein cardiomyocytes, were found to be arranged in a striated pattern in the cell interior, as well as along the periphery of cell. Furthermore, labelling the sarcolemma with di-4-ANEPPS showed that over 90% of pulmonary vein cardiomyocytes possessed T-tubules. These findings demonstrate that the frequency of spontaneous Ca2+ transients in the rat pulmonary vein are increased following higher rates of electrical stimulation and increasing the extracellular Ca2+ concentration.
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Affiliation(s)
- Alasdair D Henry
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - N MacQuaide
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - F L Burton
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - A C Rankin
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - E G Rowan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - R M Drummond
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.
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Yin X, Zhao Z, Gao L, Chang D, Xiao X, Zhang R, Chen Q, Cheng J, Yang Y, Xi Y, Xia Y. Frequency Gradient Within Coronary Sinus Predicts the Long-Term Outcome of Persistent Atrial Fibrillation Catheter Ablation. J Am Heart Assoc 2017; 6:JAHA.116.004869. [PMID: 28255079 PMCID: PMC5524018 DOI: 10.1161/jaha.116.004869] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Background The coronary sinus (CS), as a junction of the atria, contributes to atrial fibrillation (AF) by developing unstable reentry, and isolating the atria by ablation at the CS could terminate AF. The present study evaluated whether AF activities at the CS in a subset of patients contributed to AF maintenance and predicted clinical outcome of ablation. Methods and Results We studied 122 consecutive patients who had a first‐time radiofrequency ablation for persistent AF. Bipolar electrograms were obtained from multiple regions of the left atrium by a Lasso mapping catheter before ablation. Pulmonary vein isolation terminated AF in 12 patients (9.8%). Sequential stepwise ablation was conducted in pulmonary vein isolation nontermination patients and succeeded in 22 patients (18%). In the stepwise termination group, AF frequency in the proximal CS (CSp) was significantly higher (10.2±2.1 Hz versus 8.3±1.8 Hz, P<0.001), and the ratio of distal CS (CSd) to proximal CS (CSd/CSp ratio, 56.6%±10.11% versus 70.7%±9.8%, P<0.001) was significantly lower than that in the nontermination group. The stepwise logistic regression analysis indicated that the CSd/CSp ratio was an independent predictor with an odds ratio of 1.131 (95%CI 1.053‐1.214; P=0.001). With a cutoff of 67%, the patients with lower CSd/CSp ratios had significantly better index and long‐term outcomes than those with higher ratios during a follow‐up of 46±18 months. Conclusions Rapid repetitive activities in the musculature of the proximal CS may contribute to maintenance of AF after pulmonary vein isolation alone in persistent AF. A cutoff at 67%, of the CSd/CSp frequency ratio might be an indicator to stratify the subset of patients who might benefit from CS ablation.
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Affiliation(s)
- Xiaomeng Yin
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Ziming Zhao
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Lianjun Gao
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Dong Chang
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Xianjie Xiao
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Rongfeng Zhang
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Qi Chen
- Texas Heart Institute, Houston, TX
| | | | - Yanzong Yang
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Yutao Xi
- Texas Heart Institute, Houston, TX
| | - Yunlong Xia
- First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
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Ejima K, Henmi R, Iwanami Y, Yagishita D, Shoda M, Hagiwara N. Comparison of the Efficacy of Empiric Thoracic Vein Isolation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation in Patients Without Structural Heart Disease. J Cardiovasc Electrophysiol 2017; 28:266-272. [PMID: 28054729 DOI: 10.1111/jce.13159] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/16/2016] [Accepted: 12/21/2016] [Indexed: 11/28/2022]
Abstract
INTRODUCTION The guidelines suggest that an adjuvant substrate modification in addition to pulmonary vein isolation (PVI) may be needed for persistent atrial fibrillation (PerAF) assuming that catheter ablation is less successful for PerAF than paroxysmal AF (PAF). To revisit the above assumption, we compared the outcome of the same catheter ablation strategy between PAF and PerAF. METHODS AND RESULTS Two hundred and thirty-three consecutive patients (mean age 60 ± 10 years, 53 PerAF and 8 long-lasting PerAF) without structural heart disease underwent catheter ablation of AF by the same strategy using an empiric thoracic vein isolation (a wide circumferential PVI plus empiric superior vena cava isolation) as a major part of the strategy without any adjuvant substrate modification. The duration of AF in the patients with PerAF was 6 ± 4 months. During 25 ± 10 months of follow-up after single procedures, 71 (30%) patients had atrial tachyarrhythmia recurrences without antiarrhythmic drugs. A Kaplan-Meier analysis of the recurrence-free survival rate after a single procedure and after repeat procedures revealed no significant difference between the patients with PAF and those with PerAF (log-rank, P = 0.38 and P = 0.27, respectively). A Cox regression multivariate analysis of the variables including the age, gender, PerAF, body mass index, left ventricular ejection fraction, and left atrial volume index demonstrated that none of the variables were an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure. CONCLUSION In patients without underlying heart disease, the procedural outcome of an empiric thoracic vein isolation is comparable for PAF and PerAF.
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Affiliation(s)
- Koichiro Ejima
- Department of Cardiology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
| | - Ryuta Henmi
- Department of Cardiology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
| | - Yuji Iwanami
- Department of Cardiology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
| | - Daigo Yagishita
- Department of Cardiology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
| | - Morio Shoda
- Department of Cardiology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
| | - Nobuhisa Hagiwara
- Department of Cardiology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
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Ramírez-Barrera JD, Agudelo-Uribe JF, Correa-Velásquez R, González-Rivera E. Fisiopatología de la fibrilación auricular. REVISTA COLOMBIANA DE CARDIOLOGÍA 2016. [DOI: 10.1016/j.rccar.2016.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Flythe JE, Kshirsagar AV, Falk RJ, Brunelli SM. Associations of Posthemodialysis Weights above and below Target Weight with All-Cause and Cardiovascular Mortality. Clin J Am Soc Nephrol 2015; 10:808-16. [PMID: 25862779 DOI: 10.2215/cjn.10201014] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/13/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Fluid removal via ultrafiltration is a primary function of hemodialysis, and inadequate volume control is associated with significant morbidity and mortality among chronic dialysis patients. Treatment-to-treatment fluid removal goals are typically calculated on the basis of interdialytic weight gain and prescribed target weight. The clinical effect of frequent missed target weights is unclear. This study was designed to evaluate the associations of postdialysis weights above and below the prescribed target weight (separately) and outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Data were taken from a national cohort of 10,785 prevalent, thrice-weekly, in-center hemodialysis patients dialyzing from 2005 to 2008 (median time at risk, 2.1 [25th percentile, 75th percentile] years) at a single dialysis organization. Patients were characterized as having an above target weight miss if their postdialysis weight was >2 kg above target weight in at least 30% of baseline treatments (14.6% of cohort), or they were characterized as control otherwise. Below target weight miss characterization was analogous for patients with postdialysis weight >2 kg below target weight (6.6% of cohort). Coprimary endpoints were all-cause and cardiovascular mortality. RESULTS Above target weight miss in at least 30% of treatments (versus not) was associated with greater all-cause mortality (adjusted hazard ratio, 1.28; 95% confidence interval, 1.15 to 1.43); and below target weight miss in at least 30% of treatments (versus not) was associated with greater all-cause mortality (adjusted hazard ratio, 1.22; 95% confidence interval, 1.05 to 1.40). Both above and below target weight misses were also significantly associated with greater cardiovascular mortality. Secondary analyses demonstrated dose-response relationships between target weight misses and mortality. Results from sensitivity analyses considering the difference in postdialysis and target weights as a proportion of body weight were analogous to the primary results. CONCLUSIONS Postdialysis weights >2 kg above and below target weight are associated with higher all-cause and cardiovascular mortality. Consistent target weight achievement is a viable target for improving fluid management.
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Affiliation(s)
- Jennifer E Flythe
- University of North Carolina Kidney Center, Division of Nephrology and Hypertension, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina; Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts; and
| | - Abhijit V Kshirsagar
- University of North Carolina Kidney Center, Division of Nephrology and Hypertension, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Ronald J Falk
- University of North Carolina Kidney Center, Division of Nephrology and Hypertension, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Steven M Brunelli
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts; and DaVita Clinical Research, Minneapolis, Minnesota
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Mamchur S, Mamchur I, Khomenko E, Kokov A, Bokhan N, Sherbinina D. Mechanical function of left atrium and pulmonary vein sleeves before and after their antrum isolation. MEDICINA-LITHUANIA 2014; 50:353-9. [PMID: 25541269 DOI: 10.1016/j.medici.2014.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 11/10/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND AND OBJECTIVE Pulmonary vein (PV) sleeves are established as the main substrate taking part in the mechanisms of atrial fibrillation (AF) initiation. However, we have extremely few data concerning their physiological role in the heart contractility. The aim of the study was to estimate the mechanical function of the left atrium (LA) and PV sleeves before and early after their isolation. MATERIALS AND METHODS A total of 17 patients with a mean age of 57.4±8.3 years who underwent PVs isolation due to AF were enrolled in the study. A day before the procedure a computed tomography (CT) of the LA and PVs and dopplerography of transmitral flow were performed. During the procedure the mechanical function of the LA and PV sleeves were estimated by transesophageal echocardiography and manometry in the left heart chambers. RESULTS During the invasive study the patterns of the heart chambers and PV sleeves pressure were identified. These patterns confirmed the active role of the PV sleeves in LA filling and active LA relaxation during left ventricular systole. After PV isolation an alteration of transmitral blood flow and increase of LA pressure were registered. However, diastolic dysfunction was ruled out by LV manometry, thereby testifying LA mechanical function disturbance. The change in PV hemodynamics also occurred as a result of the decrease in PV sleeves contractility, revealed by manometry and paired CT scans. CONCLUSIONS The PVs take an active part in left atrial filling by contraction of their sleeves. Antrum isolation of the PVs leads to the deterioration of their contractility and LA reservoir function.
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Affiliation(s)
- Sergey Mamchur
- Department of Arrhythmology and Pacing, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russian Federation.
| | - Irina Mamchur
- Department of Arrhythmology and Pacing, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russian Federation
| | - Egor Khomenko
- Department of Arrhythmology and Pacing, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russian Federation
| | - Alexander Kokov
- Department of Arrhythmology and Pacing, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russian Federation
| | - Nikita Bokhan
- Department of Arrhythmology and Pacing, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russian Federation
| | - Diana Sherbinina
- Department of Arrhythmology and Pacing, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russian Federation
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Differential Effects of Adrenergic Antagonists (Carvedilol vs Metoprolol) on Parasympathetic and Sympathetic Activity: A Comparison of Clinical Results. Heart Int 2014. [DOI: 10.5301/heart.2014.12496] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
Background Coronary heart disease (CHD) is a major health concern, affecting nearly half the middle-age population and responsible for nearly one-third of all deaths. Clinicians have responsibilities beyond diagnosing CHD, including risk stratification of patients for major adverse cardiac events (MACE), modifying the risks and treating the patient. In this first of a two-part review, identifying risk factors is reviewed, including more potential benefit from autonomic testing. Methods Traditional and non-traditional, and modifiable and non-modifiable risk factors for MACE where compared, including newer risk factors, such as inflammation, carotid intimal thickening, ankle-brachial index, CT calcium scoring, and autonomic function testing, specifically independent measurement of parasympathetic and sympathetic (P&S) activity. Results The Framingham Heart Study, and others, have identified traditional risk factors for the development of CHD. These factors effectively target high-risk patients, but a large number of individuals who will develop CHD and MACE are not identified. Many patients with CHD who appear to be well-managed by traditional therapies still experience MACE. In order to identify these patients, other possible risk factors have been explored. Advanced autonomic dysfunction, and its more severe form, cardiac autonomic neuropathy, have been strongly associated with an elevated risk of cardiac mortality and are diagnosable through P&S testing. Conclusions Independent measures of P&S activity, provides additional information and has the potential to incrementally add to risk assessment. This additional information enables physicians to (1) specifically target more high-risk patients and (2) titrate therapies, with autonomic testing guidance, in order to minimize risk of cardiac mortality and morbidity.
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Revisiting heart activation-conduction physiology, part I: atria. J Interv Card Electrophysiol 2014; 40:9-15. [PMID: 24671296 DOI: 10.1007/s10840-014-9884-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 02/04/2014] [Indexed: 10/25/2022]
Abstract
This discussion paper re-examines the conduction-activation of the atria, based on observations, with respect to the complexity of the heart as an organ with a brain, and its evolution from a peristaltic tube. The atria do not require a specialized conduction system because they use the subendocardial layer to produce centripetal transmural activation fronts, regardless of the anatomical and histological organization of the transmural atrial wall. This has been described as "two-layer" physiology which provides robust transmission of activation from the sinus to the AV node via a centripetal transmural activation front. New productive insights can come from re-examining the physiology, not only during sinus rhythm but also during atrial tachycardias, in particular atrial flutter and atrial fibrillation (AF). During common flutter, the areas of slow conduction, in the isthmus and following trabeculations, particularly the subendocardial layer confines conduction through the trabeculations which supports re-entry. During experimental or postoperative flutter, the circular 2D activation around the obstacle follows the physiological transmural activation. Understanding this physiology offers insights into AF. During acute or protracted AF, the presence of stationary or drifting rotors is characteristic and consistent with normal physiological 2D atrial activation, suggesting that suppressing physiological transmural activation of AF will permanently restore normal sinus node atrial activation. In contrast, during permanent AF, normal 2D activation is abolished; the presence of transmural, serpentine, and chaotic atrial activation suggests that the normal physiological activation pattern has been replaced by a new, irreversible variety of atrial conduction that is a new physiology, which is consistent with evolution of complex systems.
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Kittnar O, Yang SG, Mlček M. Experimental evaluation of the cardiac rhythm originating in myocardial sleeves of pulmonary veins using a monophasic action potential. Physiol Res 2013; 62:S49-56. [PMID: 24329703 DOI: 10.33549/physiolres.932604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Spontaneous depolarization similar to that from the sinus node was documented from the myocardial sleeves of pulmonary veins (PV) after isolation procedures. It was then hypothesized that sinus node-like tissue is present in the PVs of humans. Based on a number of features, the myocardium of myocardial sleeves (MS) is highly arrhythmogenic. Membrane potentials originating from MS are invariably recordable at the PVs ostia in patients with atrial fibrillation (AF) and delayed conduction around the PVs ostia may play a role in re-entry process responsible for the initiation and maintenance of AF. Diagnostic and therapeutic evidence of premature atrial beats induced in MS of PVs and resulting in launch of AF was detected by 3D electroanatomic method of monophasic action potential (MAP). MAP recording plays an important role in a direct view of human myocardial electrophysiology under both physiological and pathological conditions. Its crucial importance lies in the fact that it enables the study of the action potential of myocardial cell in vivo and, therefore, the study of the dynamic relation of this potential with all the organism variables. The knowledge of pathological MAPs from PV myocardial sleeves can help us to confirm a diagnosis when finding the similar action potential morphology. MAP can be also used to evaluate the therapeutic efficiency of vagal nerves suppression, radiofrequency ablation or other treatment procedures in PVs myocardial sleeves as well as for post-treatment following up.
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Affiliation(s)
- O Kittnar
- Institute of Physiology, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
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Ciszewski P, Tyczka J, Nadolski J, Roszak M, Dyszkiewicz W. Lower preoperative fluctuation of heart rate variability is an independent risk factor for postoperative atrial fibrillation in patients undergoing major pulmonary resection. Interact Cardiovasc Thorac Surg 2013; 17:680-6. [PMID: 23832838 DOI: 10.1093/icvts/ivt238] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES The following study presents a special independent atrial fibrillation (AF) risk factor-preoperative fluctuation of heart rate variability (HRV), as well as other perioperative AF risk factors in patients qualified for pneumonectomy and undergoing pneumonectomy or lobectomy for lung cancer. METHODS The prospective study was performed in patients who had undergone anatomical resection for non-small-cell lung cancer. A total of 117 patients (92 men and 25 women) qualified for statistical research. In order to determine the risk factors, all patients were divided into two groups: Group A-98 patients without AF and Group B-19 patients with AF during the perioperative time. A number of different risk factors of AF have been analysed and further divided into preoperative, operative and postoperative. RESULTS Postoperative AF occurred in 19 patients (16%), all of them were male. The patients with higher short-term HRV parameters (SD1, RMSSD), slower mean heart rate and those with a lower fluctuation of HRV-related parameters (HRV Afternoon, Night, Day (A/N/D)) before the operation, were more prone to AF. Postoperative risk of AF was higher in patients with a higher number of ventricular ectopic beats before the operation, a higher number of supraventricular and ventricular ectopic beats and a higher maximal heart rate after the operation. Statistical analysis revealed that male gender and the extent of pulmonary resection, particularly left pneumonectomy, constituted significant risk factors. AF was more often observed in patients who had ASA physical status score of III, in comparison with ASAI and ASAII patients. CONCLUSIONS Along with other concomitant AF risk factors presented in this work, the evaluation of the fluctuation tendencies of HRV parameters should be taken into consideration before any major lung resection. The balance disturbance between the sympathetic and parasympathetic nervous systems is responsible for AF.
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Affiliation(s)
- Pawel Ciszewski
- Department of Anesthesiology and Intensive Care, Poznan University of Medical Sciences, Poznan, Poland
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Flythe JE, Curhan GC, Brunelli SM. Disentangling the ultrafiltration rate-mortality association: the respective roles of session length and weight gain. Clin J Am Soc Nephrol 2013; 8:1151-61. [PMID: 23493384 DOI: 10.2215/cjn.09460912] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND AND OBJECTIVES Rapid ultrafiltration rate is associated with increased mortality among hemodialysis patients. Ultrafiltration rates are determined by interdialytic weight gain and session length. Although both interdialytic weight gain and session length have been linked to mortality, the relationship of each to mortality, independent of the other, is not adequately defined. This study was designed to evaluate whether shorter session length independent of weight gain and larger weight gain independent of session length are associated with increased mortality. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Data were taken from a national cohort of 14,643 prevalent, thrice-weekly, in-center hemodialysis patients dialyzing from 2005 to 2009 (median survival time, 25 months) at a single dialysis organization. Patients with adequate urea clearance and delivered dialysis session ≥240 and <240 minutes were pair-matched on interdialytic weight gain (n=1794), and patients with weight gain ≤3 and >3 kg were pair-matched on session length (n=2114); mortality associations were estimated separately. RESULTS Compared with delivered session length ≥240, session length <240 minutes was associated with increased all-cause mortality (adjusted hazard ratio [95% confidence interval], 1.32 [1.03 to 1.69]). Compared with weight gain ≤3, weight gain >3 kg was associated with increased mortality (1.29 [1.01 to 1.65]). The associations were consistent across strata of age, sex, weight, and weight gain and session length. Secondary analyses demonstrated dose-response relationships between both and mortality. CONCLUSIONS Among patients with adequate urea clearance, shorter dialysis session length and greater interdialytic weight gain are associated with increased mortality; thus, both are viable targets for directed intervention.
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Affiliation(s)
- Jennifer E Flythe
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
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Faggioni L, Zampa V, Ortori S, Picano E, De Lucia R, Soldati E, Bongiorni MG, Neri E, Bartolozzi C. Time-resolved contrast-enhanced magnetic resonance angiography (CEMRA) of the left atrium–pulmonary veins complex with half dose of intravenous gadolinium-based contrast agent. Technical feasibility and comparison with a conventional CEMRA, full contrast dose protocol. Eur J Radiol 2012; 81:250-6. [DOI: 10.1016/j.ejrad.2010.12.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 12/28/2010] [Indexed: 11/30/2022]
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Nonpharmacologic management of atrial fibrillation: role of the pulmonary veins and posterior left atrium. Heart Rhythm 2011; 6:S5-S11. [PMID: 19959144 DOI: 10.1016/j.hrthm.2009.07.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Indexed: 11/21/2022]
Abstract
Nonpharmacologic approaches for the management of atrial fibrillation are rapidly emerging as the mainstay for definitive management of this arrhythmia. Over the past several years, numerous studies reported in the literature have highlighted various aspects of the pathophysiologic mechanisms underlying atrial fibrillation. The purpose of this review is to place the current approaches being used for arrhythmia management in the context of the current knowledge of about arrhythmia mechanisms.
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Lee G, Spence S, Teh A, Goldblatt J, Larobina M, Atkinson V, Brown R, Morton JB, Sanders P, Kistler PM, Kalman JM. High-density epicardial mapping of the pulmonary vein-left atrial junction in humans: insights into mechanisms of pulmonary vein arrhythmogenesis. Heart Rhythm 2011; 9:258-64. [PMID: 21907170 DOI: 10.1016/j.hrthm.2011.09.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 09/30/2011] [Indexed: 11/26/2022]
Abstract
BACKGROUND The pulmonary veins (PVs) and the PV-LA (left atrium) junction are established sources of triggers initiating atrial fibrillation. In addition, they have been implicated in the maintenance of arrhythmia. OBJECTIVE To undertake high-density electrophysiological characterization of the right superior PV-LA junction in humans. METHODS Mapping was performed in 18 patients without a history of atrial fibrillation undergoing cardiac surgery. A high-density epicardial plaque was positioned at the anterior right superior pulmonary vein covering 3 regions: LA, PV-LA junction, and the PV. Isochronal maps were created during (1) sinus rhythm (SR); (2) LA pacing (LA-Pace); (3) PV pacing (PV-Pace); (4) LA programmed electrical stimulation (LA-PES); and (5) PV programmed electrical stimulation (PV-PES). Regional differences in conduction slowing/conduction block (CS/CB) and the prevalence of fractionated signals (FS) and double potentials (DPs) were assessed. RESULTS A region of isochronal crowding representing CS/CB developed at the PV-LA junction in 84% of the maps. Three distinct activation patterns were seen. Pattern 1: Uniform SR activation without CS/CB. LA-Pace and PES caused 1 to 2 lines of isochronal crowding (CS/CB) at the PV-LA junction. Pattern 2: CS/CB occurred at the PV-LA junction in SR. LA/PV-Pace and LA/PV-PES caused an increase in CS/CB at the PV-LA junction with widely split DPs and FS. Pattern 3: A single incomplete line of CS at the PV-LA junction in SR. With LA/PV pacing and LA/PV-PES, multiple lines (≥3) of CS/CB developed at the PV-LA junction with evidence of circuitous activation and a marked increase in DPs and FS. CONCLUSION High-density epicardial mapping of the right superior pulmonary vein demonstrates marked functional conduction delay and circuitous activation patterns at the PV-LA junction, creating the substrate for reentry.
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Affiliation(s)
- Geoffrey Lee
- Department of Cardiology, The Royal Melbourne Hospital, Melbourne, Australia
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Kanbay M, Solak Y, Covic A, Goldsmith D. Sudden cardiac death in patients with chronic kidney disease: prevention is the sine qua non. Kidney Blood Press Res 2011; 34:269-76. [PMID: 21691130 DOI: 10.1159/000326904] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Despite developments in the technology of dialysis procedures and improvements in the understanding of systemic derangements related to chronic kidney disease (CKD), cardiovascular disease is the major cause of death. Unfortunately, the leading subset of cardiovascular disease death is sudden cardiac death (SCD). To date much effort has been exerted to figure out the clues pointing to the risk of future development of SCD in patients with CKD. However, none of these factors satisfactorily detects a truly vulnerable dialysis patient. Thus, recently, it has been advocated that a combination of noninvasive risk assessment methods, carefully chosen to reflect the different aspects of the underlying pathology and changes in the myocardial substrate in CKD, could help to identify patients at high risk of SCD within the CKD. In this review, we aimed to summarize what is known about risk stratification of patients with CKD and appropriate prevention strategies with a special emphasis on recent developments and the use of complimentary tests perhaps as a risk prediction rule.
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Affiliation(s)
- Mehmet Kanbay
- Division of Nephrology, Department of Medicine, Kayseri Training and Research Hospital, Kayseri, Turkey.
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Flythe JE, Brunelli SM. The risks of high ultrafiltration rate in chronic hemodialysis: implications for patient care. Semin Dial 2011; 24:259-65. [PMID: 21480996 DOI: 10.1111/j.1525-139x.2011.00854.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
As dialytic practice has evolved, hemodialysis (HD) adequacy has come to be defined in terms of small molecule clearance. A growing body of evidence suggests that fluid dynamics, specifically ultrafiltration rate (UFR), bear clinical and physiological significance and should perhaps play a more central role in titrating HD therapy. Three recent studies have shown an independent association between higher UFR and mortality. Further work is needed to determine whether this relationship represents a direct toxic effect of rapid fluid perturbations or whether this association is a consequence of confounding on the basis of large interdialytic weight gain, as each would prompt a different therapeutic response. This mounting evidence builds the case that fluid management should play a more central role in the dialytic prescription and that more individualized approaches to fluid management should be encouraged.
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Affiliation(s)
- Jennifer E Flythe
- Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Nakano H, Williams E, Hoshijima M, Sasaki M, Minamisawa S, Chien KR, Nakano A. Cardiac origin of smooth muscle cells in the inflow tract. J Mol Cell Cardiol 2010; 50:337-45. [PMID: 20974149 DOI: 10.1016/j.yjmcc.2010.10.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/14/2010] [Accepted: 10/12/2010] [Indexed: 11/26/2022]
Abstract
Multipotent Isl1(+) heart progenitors give rise to three major cardiovascular cell types: cardiac, smooth muscle, and endothelial cells, and play a pivotal role in lineage diversification during cardiogenesis. A critical question is pinpointing when this cardiac-vascular lineage decision is made, and how this plasticity serves to coordinate cardiac chamber and vessel growth. The posterior domain of the Isl1-positive second heart field contributes to the SLN-positive atrial myocardium and myocardial sleeves in the cardiac inflow tract, where myocardial and vascular smooth muscle layers form anatomical and functional continuity. Herein, using a new atrial specific SLN-Cre knockin mouse line, we report that bipotent Isl1(+)/SLN(+) transient cell population contributes to cardiac as well as smooth muscle cells at the heart-vessel junction in cardiac inflow tract. The Isl1(+)/SLN(+) cells are capable of giving rise to cardiac and smooth muscle cells until late gestational stages. These data suggest that the cardiac and smooth muscle cells in the cardiac inflow tract share a common developmental origin. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited".
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Affiliation(s)
- Haruko Nakano
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
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Krane V, Berger M, Lilienthal J, Winkler K, Schambeck C, Wanner C. Antibodies to platelet factor 4-heparin complex and outcome in hemodialysis patients with diabetes. Clin J Am Soc Nephrol 2010; 5:874-81. [PMID: 20185595 DOI: 10.2215/cjn.01170209] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Hemodialysis patients with type 2 diabetes exhibit an excessive cardiovascular risk and regularly receive heparin. We tested whether antibodies to the platelet factor 4-heparin complex (PF4-H-AB) contribute to outcome. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In 1255 hemodialysis patients with type 2 diabetes, the German Diabetes Dialysis Study evaluated the effect of atorvastatin (20 mg/d) versus placebo. In a post hoc analysis, the association among PF4-H-ABs, biochemistry, and prespecified, centrally adjudicated end points (combined cardiovascular end point [CVE], all-cause mortality, sudden death, myocardial infarction, stroke) was investigated. RESULTS During 4 years, 460 patients reached the CVE; 605 died, 159 of sudden death. Myocardial infarction and stroke occurred in 199 and 97 patients, respectively. Positive PF4-H-AB status was found in 231 (18.7%) of 1236 tested patients and was associated with lower albumin, higher C-reactive protein, and arrhythmia. In a multivariate model adjusted for demographics, comorbidities, and biochemistry, PF4-H-ABs were associated with sudden death. No significant association between PF4-H-ABs and all-cause mortality, myocardial infarction, stroke, or the CVE was observed. Detecting an interaction between acetylsalicylic acid and PF4-H-ABs regarding sudden death and mortality, we found that the association between PF4-H-ABs and outcomes was restricted to patients with acetylsalicylic acid use, most likely because of indication bias. CONCLUSIONS In hemodialysis patients who have type 2 diabetes and are treated with acetylsalicylic acid, PF4-H-ABs are associated with sudden and all-cause death. Further studies are needed to elucidate this association.
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Affiliation(s)
- Vera Krane
- University Hospital Würzburg, Department of Internal Medicine I, Division of Nephrology, Oberdürrbacher Strasse 6, D-97080 Würzburg, Germany.
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Drechsler C, Krane V, Ritz E, März W, Wanner C. Glycemic control and cardiovascular events in diabetic hemodialysis patients. Circulation 2010; 120:2421-8. [PMID: 19948978 DOI: 10.1161/circulationaha.109.857268] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Patients on maintenance dialysis treatment experience an excess mortality, predominantly of sudden cardiac death. Poor glycemic control is associated with cardiovascular comorbidities in the general population. This study investigated the impact of glycemic control on cardiac and vascular outcomes in diabetic hemodialysis patients. METHODS AND RESULTS Glycohemoglobin A1c (HbA(1c)) was measured in 1255 hemodialysis patients with type 2 diabetes mellitus who participated in the German Diabetes and Dialysis Study (4D Study) and were followed up for a median of 4 years. Using Cox regression analyses, we determined hazard ratios to reach prespecified, adjudicated end points according to HbA(1c) levels at baseline: sudden cardiac death (n=160), myocardial infarction (n=200), stroke (n=103), cardiovascular events (n=469), death caused by heart failure (n=41), and all-cause mortality (n=617). Patients had a mean age of 66+/-8 years (54% male) and mean HbA(1c) of 6.7+/-1.3%. Patients with an HbA(1c) >8% had a >2-fold higher risk of sudden death compared with those with an HbA(1c) < or =6% (hazard ratio, 2.14; 95% confidence interval, 1.33 to 3.44), persisting in multivariate models. With each 1% increase in HbA(1c), the risk of sudden death rose significantly by 18%; similarly, cardiovascular events and mortality increased by 8%. There was a trend for higher risks of stroke and deaths resulting from heart failure, whereas myocardial infarction was not affected. The increased risks of both cardiovascular events and mortality were explained mainly by the impact of HbA(1c) on sudden death. CONCLUSIONS Poor glycemic control was strongly associated with sudden cardiac death in diabetic hemodialysis patients, which accounted for increased cardiovascular events and mortality. In contrast, myocardial infarction was not affected. Whether interventions achieving tight glycemic control decrease sudden death requires further evaluation. Clinical Trial Registration- URL: http://www.clinicalstudyresults.org. Unique identifier: CT-981-423-239.
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Affiliation(s)
- Christiane Drechsler
- Department of Medicine, Division of Nephrology, University Hospital, Oberdürrbacherstrasse 6, D-97080 Würzburg, Germany.
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Doisne N, Maupoil V, Cosnay P, Findlay I. Catecholaminergic automatic activity in the rat pulmonary vein: electrophysiological differences between cardiac muscle in the left atrium and pulmonary vein. Am J Physiol Heart Circ Physiol 2009; 297:H102-8. [PMID: 19429824 DOI: 10.1152/ajpheart.00256.2009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ectopic activity in cardiac muscle within pulmonary veins (PVs) is associated with the onset and the maintenance of atrial fibrillation in humans. The mechanism underlying this ectopic activity is unknown. Here we investigate automatic activity generated by catecholaminergic stimulation in the rat PV. Intracellular microelectrodes were used to record electrical activity in isolated strips of rat PV and left atrium (LA). The resting cardiac muscle membrane potential was lower in PV [-70 +/- 1 (SE) mV, n = 8] than in LA (-85 +/- 1 mV, n = 8). No spontaneous activity was recorded in PV or LA under basal conditions. Norepinephrine (10(-5) M) induced first a hyperpolarization (-8 +/- 1 mV in PV, -3 +/- 1 mV in LA, n = 8 for both) then a slowly developing depolarization (+21 +/- 2 mV after 15 min in PV, +1 +/- 2 mV in LA) of the resting membrane potential. Automatic activity occurred only in PV; it was triggered at approximately -50 mV, and it occurred as repetitive bursts of slow action potentials. The diastolic membrane potential increased during a burst and slowly depolarized between bursts. Automatic activity in the PV was blocked by either atenolol or prazosine, and it could be generated with a mixture of cirazoline and isoprenaline. In both tissues, cirazoline (10(-6) M) induced a depolarization (+37 +/- 2 mV in PV, n = 5; +5 +/- 1 mV in LA, n = 5), and isoprenaline (10(-7) M) evoked a hyperpolarization (-11 +/- 3 mV in PV, n = 7; -3 +/- 1 mV in LA, n = 6). The differences in membrane potential and reaction to adrenergic stimulation lead to automatic electrical activity occurring specifically in cardiac muscle in the PV.
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Affiliation(s)
- Nicolas Doisne
- Centre National de la Recherche Scientifique FRE 3092, Faculté des Sciences, Université François-Rabelais, Tours, France
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Govindan M, Catanchin A, Camm AJ. The place of hybrid therapies with drugs to supplement nonpharmacological therapies in atrial fibrillation. J Cardiovasc Pharmacol 2008; 52:210-21. [PMID: 18806601 DOI: 10.1097/fjc.0b013e3181799677] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Atrial fibrillation (AF) is one of the most common cardiac arrhythmias, and its prevalence continues to rise as the aged population increases. Comparative studies of rhythm control and rate control have been equivocal; however, the benefits of rhythm control may have been offset by the limitations of antiarrhythmic drugs. More recently, nonpharmacological therapies have emerged that provide hope of more effective rhythm control. Catheter ablation techniques have gained favour with high success rates in specialized centers, although these techniques are not without complications and require considerable expertise. Pacing therapies designed to reduce harmful right ventricular pacing and increase physiological pacing have shown benefit in AF patients with bradycardia. Despite this progress, no single modality confers benefit for all patients. Strategies to combine these treatment modalities in a hybrid approach has shown increasing promise for subgroups of AF patients.
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Affiliation(s)
- Malini Govindan
- Division of Cardiac and Vascular Sciences, St Georges Hospital University of London, London, UK.
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Abstract
Atrial fibrillation (AF) undoubtedly has become one of the most well studied arrhythmias today in terms of pathophysiology and diagnostic and therapeutic (interventional) electrophysiology. Although it lends itself to an apparently easy diagnosis on a surface ECG, myriad electromechanical mechanisms underlie its origin. An era of technology has been reached that makes AF not only "treatable" but also potentially "curable." This article aims at walking through the historical corridors and maze that have led to the present-day understanding of this most common yet complex arrhythmia.
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Affiliation(s)
- Atul Khasnis
- Michigan State University, Thoracic and Cardiovascular Institute, Sparrow Health System, 405 West Greenlawn, Suite 400, Lansing, MI 48910, USA
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