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Khan Z, Besis G, Tomson J. Tachycardia-Induced Cardiomyopathy in a Young Healthy Patient: A Case Report. Cureus 2022; 14:e28932. [PMID: 36237783 PMCID: PMC9543122 DOI: 10.7759/cureus.28932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2022] [Indexed: 11/05/2022] Open
Abstract
Tachycardia-induced cardiomyopathy (TIC) can result in both systolic and/or diastolic ventricular dysfunction as a result of the prolonged fast heart rate which is reversible upon controlling the fast heart rate or arrhythmia. The exact heart rate that can lead to this is not clear, however, a heart rate > 100 in general needs attention. Tachycardia-induced cardiomyopathy is a well-established cause of left ventricular dysfunction which usually happens due to an increased atrial or ventricular rate. The incidence of TIC is very low although the exact incidence is unclear. It should be considered in all patients with dilated cardiomyopathy or those with no obvious explanation for dilated cardiomyopathy and in presence of tachycardia or atrial fibrillation with a rapid ventricular response. Tachycardia-induced cardiomyopathy has also been labeled as arrhythmia-induced cardiomyopathy lately. We present a case of a 50-year-old patient who presented with a fever of 39oC, feeling generally unwell, had a sore throat, and collapsed at home after several episodes of vomiting after two days of intense exercise. He was diagnosed with suspected tonsillitis and was treated with co-amoxiclav. He was exercising over 10 hours weekly for the last two months in the gym for the Ironman triathlon in London. An echocardiogram showed severe left ventricular systolic dysfunction (LVSD) with a left ventricular ejection fraction (LVEF) of 25%. An electrocardiogram showed sinus tachycardia with a right bundle branch block (RBBB). Cardiac magnetic resonance imaging (CMR) showed normal biventricular function with an ejection fraction (EF) of 71% four months later. The patient was diagnosed with tachycardia-induced cardiomyopathy. This case is unique as the patient presented with transient severe LVSD after training for the ironman triathlon and spontaneous recovery.
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Tong F, Sun Z. Therapeutic Effect of His-Purkinje System Pacing Proportion on Persistent Atrial Fibrillation Patients With Heart Failure. Front Cardiovasc Med 2022; 9:829733. [PMID: 35282341 PMCID: PMC8907546 DOI: 10.3389/fcvm.2022.829733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundHis-Purkinje system pacing (HPSP) combined with atrioventricular node ablation is an effective therapy for atrial fibrillation (AF) patients with heart failure (HF). However, atrioventricular node ablation has some limitations and disadvantages. HPSP combined with β -blockers reduces intrinsic heart rate and increases pacing proportion, which may be an alternative to HPSP combined with atrioventricular node ablation. This study was to assess the therapeutic effect of different HPSP proportion on AF patients with HF.MethodsThe study enrolled 30 consecutive persistent AF patients with HF who underwent HPSP. Heart rate was controlled by medical therapy. NYHA class, NT-proBNP, echocardiographic parameters were assessed at follow-up. MACE was defined as the composite endpoint of readmission for HF and cardiac mortality.ResultsThe AUC of pacing proportion for predicting MACE was 0.830 (SE = 0.140, 95%CI:0.649–0.941, p = 0.018), the optimal cut-off point of pacing proportion to predict MACE by ROC analysis was 71% (sensitivity:83.3%, specificity: 91.7%). In high pacing proportion group (>71%), there were significant improvements of NYHA class, NT-proBNP, LVEF and LVEDD from the baseline in wide QRS complex (QRSd>120 ms) patients and HFrEF patients at half year follow-up, and there were significant improvements in NYHA class, NT-proBNP from baseline in narrow QRS complex (QRSd ≤ 120 ms) patients and HFpEF patients at half year follow-up, moderate but no significant improvements of LVEF and LVEDD were observed in these patients. In low pacing proportion group (≤ 71%), there were no significant improvements of NT-proBNP, LVEDD or LVEF regardless of baseline QRS duration or LVEF (p > 0.05).ConclusionHigh pacing proportion (>71%) of HPSP can improve clinical outcomes and echocardiographic parameters in persistent AF patients with wide QRS complex or HFrEF, and clinical outcomes in persistent AF patients with narrow QRS complex or HFpEF. High pacing proportion of HPSP has a beneficial effect on the prognosis of persistent AF patients with HF.
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Benitez‐Amaro A, Samouillan V, Jorge E, Dandurand J, Nasarre L, de Gonzalo‐Calvo D, Bornachea O, Amoros‐Figueras G, Lacabanne C, Vilades D, Leta R, Carreras F, Gallardo A, Lerma E, Cinca J, Guerra JM, Llorente‐Cortés V. Identification of new biophysical markers for pathological ventricular remodelling in tachycardia-induced dilated cardiomyopathy. J Cell Mol Med 2018; 22:4197-4208. [PMID: 29921039 PMCID: PMC6111813 DOI: 10.1111/jcmm.13699] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/17/2018] [Indexed: 11/28/2022] Open
Abstract
Our aim was to identify biophysical biomarkers of ventricular remodelling in tachycardia-induced dilated cardiomyopathy (DCM). Our study includes healthy controls (N = 7) and DCM pigs (N = 10). Molecular analysis showed global myocardial metabolic abnormalities, some of them related to myocardial hibernation in failing hearts, supporting the translationality of our model to study cardiac remodelling in dilated cardiomyopathy. Histological analysis showed unorganized and agglomerated collagen accumulation in the dilated ventricles and a higher percentage of fibrosis in the right (RV) than in the left (LV) ventricle (P = .016). The Fourier Transform Infrared Spectroscopy (FTIR) 1st and 2nd indicators, which are markers of the myofiber/collagen ratio, were reduced in dilated hearts, with the 1st indicator reduced by 45% and 53% in the RV and LV, respectively, and the 2nd indicator reduced by 25% in the RV. The 3rd FTIR indicator, a marker of the carbohydrate/lipid ratio, was up-regulated in the right and left dilated ventricles but to a greater extent in the RV (2.60-fold vs 1.61-fold, P = .049). Differential scanning calorimetry (DSC) showed a depression of the freezable water melting point in DCM ventricles - indicating structural changes in the tissue architecture - and lower protein stability. Our results suggest that the 1st, 2nd and 3rd FTIR indicators are useful markers of cardiac remodelling. Moreover, the 2nd and 3rd FITR indicators, which are altered to a greater extent in the right ventricle, are associated with greater fibrosis.
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Affiliation(s)
- Aleyda Benitez‐Amaro
- Group of Lipids and Cardiovascular PathologyICCC ProgramBiomedical Research Institute Sant Pau (IIB Sant Pau)Hospital de la Santa Creu i Sant PauBarcelonaSpain
- Institute of Biomedical Research of Barcelona (IIBB)Spanish National Research Council (CSIC)BarcelonaSpain
| | - Valerie Samouillan
- CIRIMATUniversité de ToulouseUniversité Paul Sabatier, Physique des PolymèresToulouseFrance
| | - Esther Jorge
- CIBERCVBarcelonaSpain
- Department of CardiologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant Pau (IIB Sant Pau)Universitat Autonoma de BarcelonaBarcelonaSpain
| | - Jany Dandurand
- CIRIMATUniversité de ToulouseUniversité Paul Sabatier, Physique des PolymèresToulouseFrance
| | - Laura Nasarre
- Group of Lipids and Cardiovascular PathologyICCC ProgramBiomedical Research Institute Sant Pau (IIB Sant Pau)Hospital de la Santa Creu i Sant PauBarcelonaSpain
| | - David de Gonzalo‐Calvo
- Group of Lipids and Cardiovascular PathologyICCC ProgramBiomedical Research Institute Sant Pau (IIB Sant Pau)Hospital de la Santa Creu i Sant PauBarcelonaSpain
- Institute of Biomedical Research of Barcelona (IIBB)Spanish National Research Council (CSIC)BarcelonaSpain
- CIBERCVBarcelonaSpain
| | - Olga Bornachea
- Group of Lipids and Cardiovascular PathologyICCC ProgramBiomedical Research Institute Sant Pau (IIB Sant Pau)Hospital de la Santa Creu i Sant PauBarcelonaSpain
- Institute of Biomedical Research of Barcelona (IIBB)Spanish National Research Council (CSIC)BarcelonaSpain
| | - Gerard Amoros‐Figueras
- CIBERCVBarcelonaSpain
- Department of CardiologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant Pau (IIB Sant Pau)Universitat Autonoma de BarcelonaBarcelonaSpain
| | - Colette Lacabanne
- CIRIMATUniversité de ToulouseUniversité Paul Sabatier, Physique des PolymèresToulouseFrance
| | - David Vilades
- Department of CardiologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant Pau (IIB Sant Pau)Universitat Autonoma de BarcelonaBarcelonaSpain
| | - Ruben Leta
- Department of CardiologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant Pau (IIB Sant Pau)Universitat Autonoma de BarcelonaBarcelonaSpain
| | - Francesc Carreras
- CIBERCVBarcelonaSpain
- Department of CardiologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant Pau (IIB Sant Pau)Universitat Autonoma de BarcelonaBarcelonaSpain
| | - Alberto Gallardo
- Department of PathologyHospital de la Santa Creu i Sant PauBarcelonaSpain
| | - Enrique Lerma
- Department of PathologyHospital de la Santa Creu i Sant PauBarcelonaSpain
| | - Juan Cinca
- CIBERCVBarcelonaSpain
- Department of CardiologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant Pau (IIB Sant Pau)Universitat Autonoma de BarcelonaBarcelonaSpain
| | - Jose M. Guerra
- CIBERCVBarcelonaSpain
- Department of CardiologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant Pau (IIB Sant Pau)Universitat Autonoma de BarcelonaBarcelonaSpain
| | - Vicenta Llorente‐Cortés
- Group of Lipids and Cardiovascular PathologyICCC ProgramBiomedical Research Institute Sant Pau (IIB Sant Pau)Hospital de la Santa Creu i Sant PauBarcelonaSpain
- Institute of Biomedical Research of Barcelona (IIBB)Spanish National Research Council (CSIC)BarcelonaSpain
- CIBERCVBarcelonaSpain
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Prabhu S, Voskoboinik A, Kaye DM, Kistler PM. Atrial Fibrillation and Heart Failure - Cause or Effect? Heart Lung Circ 2017; 26:967-974. [PMID: 28684095 DOI: 10.1016/j.hlc.2017.05.117] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/09/2017] [Indexed: 10/19/2022]
Abstract
There are emerging epidemics of atrial fibrillation (AF) and heart failure in most developed countries, with a significant health burden. Due to many shared pathophysiological mechanisms, which facilitate the maintenance of each condition, AF and heart failure co-exist in up to 30% of patients. In the circumstance where known structural causes of heart failure (such as myocardial infarction) are absent, patients presenting with both conditions present a unique challenge, particularly as the temporal relationship of each condition can often remain elusive from the clinical history. The question of whether the AF is driving, or significantly contributing to the left ventricular (LV) dysfunction, rather than merely a consequence of heart failure, has become ever more pertinent, especially as catheter ablation now offers a significant advancement over existing rhythm control strategies. This paper will review the inter-related physiological drivers of AF and heart failure before considering the implications from the outcomes of recent clinical trials in patients with AF and heart failure.
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Affiliation(s)
- Sandeep Prabhu
- The Alfred Hospital, Melbourne, Vic, Australia; Baker Heart and Diabetes Institute, Melbourne, Vic, Australia; University of Melbourne, Melbourne, Vic, Australia
| | - Aleksandr Voskoboinik
- The Alfred Hospital, Melbourne, Vic, Australia; Baker Heart and Diabetes Institute, Melbourne, Vic, Australia; University of Melbourne, Melbourne, Vic, Australia
| | - David M Kaye
- The Alfred Hospital, Melbourne, Vic, Australia; Baker Heart and Diabetes Institute, Melbourne, Vic, Australia
| | - Peter M Kistler
- The Alfred Hospital, Melbourne, Vic, Australia; Baker Heart and Diabetes Institute, Melbourne, Vic, Australia; University of Melbourne, Melbourne, Vic, Australia.
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WANG JINGFENG, GONG XUE, CHEN HAIYAN, QIN SHENGMEI, ZHOU NIANWEI, SU YANGANG, GE JUNBO. Effect of Cardiac Resynchronization Therapy on Myocardial Fibrosis and Relevant Cytokines in a Canine Model With Experimental Heart Failure. J Cardiovasc Electrophysiol 2017; 28:438-445. [PMID: 28127817 DOI: 10.1111/jce.13171] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 01/15/2017] [Accepted: 01/18/2017] [Indexed: 02/06/2023]
Affiliation(s)
- JINGFENG WANG
- Department of Cardiology; Shanghai Institute of Medical Imaging, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; Shanghai China
| | - XUE GONG
- Department of Echocardiography; Shanghai Institute of Medical Imaging, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; Shanghai China
| | - HAIYAN CHEN
- Department of Echocardiography; Shanghai Institute of Medical Imaging, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; Shanghai China
| | - SHENGMEI QIN
- Department of Cardiology; Shanghai Institute of Medical Imaging, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; Shanghai China
| | - NIANWEI ZHOU
- Department of Echocardiography; Shanghai Institute of Medical Imaging, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; Shanghai China
| | - YANGANG SU
- Department of Cardiology; Shanghai Institute of Medical Imaging, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; Shanghai China
| | - JUNBO GE
- Department of Cardiology; Shanghai Institute of Medical Imaging, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; Shanghai China
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Affiliation(s)
- Hassan A Mohamed
- Department of Medicine, Division of Cardiology, Regina General Hospital, Regina, SK, Canada
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Kvistad CE, Logallo N, Thomassen L, Moen G, Waje-Andreassen U, Naess H. Diffusion-weighted lesions in stroke patients with transient symptoms--where are they located? Cerebrovasc Dis 2014; 38:219-25. [PMID: 25359097 DOI: 10.1159/000366264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 07/29/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND MR diffusion-weighted imaging (DWI) has revolutionized neuroimaging and contributed to a tissue-based redefinition of transient ischemic attack (TIA). Stroke patients with DWI lesions may have neurological symptoms that resolve completely within 24 h, suggesting successful vessel recanalization. Prior studies of stroke patients with transient symptoms have not found any predilection for DWI lesions in any specific territory. Other studies have, however, reported an association between higher brain dysfunction and presence of DWI lesions in patients with transient ischemic symptoms, suggesting a high rate of cortical affection in these patients. We sought to see whether DWI location in stroke patients with transient symptoms <24 h differed from those with persistent symptoms ≥ 24 h. We hypothesized an association between transient symptoms <24 h and cortical DWI lesion localization due to a possible higher rate of vessel recanalization in patients with transient symptoms causing distal cortical infarctions. METHODS Ischemic stroke patients examined with DWI and admitted within 24 h after symptom onset between February 2006 and November 2013 were prospectively registered in a database (The Bergen NORSTROKE Registry). Based on neurological examination 24 h after admission, patients were classified as having either transient symptoms <24 h (DWI <24) or persistent symptoms ≥ 24 h (DWI ≥ 24). DWI lesions were classified into different groups depending on lesion location: cortical lesions, confined to the supratentorial cortex; large subcortical lesions, located in the hemispheric white matter, basal ganglia, internal capsule, thalamus or corona radiate with a diameter ≥ 15 mm; lacunar lesions, located in the same territory as large subcortical lesions with a diameter <15 mm; mixed cortical-subcortical lesions, located in both supratentorial cortex and subcortex; cerebellar lesions, confined to the cerebellum; brain stem lesions, confined to the brain stem; multiple locations, located in more than one of the above defined areas. RESULTS A total of 142 ischemic stroke patients had DWI <24 and 830 DWI ≥ 24. Cortical DWI location was more frequent in patients with DWI <24 (54.2% vs. 29.5%, p < 0.001), while proportions of mixed cortical-subcortical lesions (13.4% vs. 26.5%, p = 0.001) and lesions with multiple locations (5.6% vs. 11.1%, p = 0.048) were less frequent as compared to DWI ≥ 24. Cortical DWI location was independently associated with DWI <24 when adjusted for confounders in multiple regression analyses (OR 1.89, 95% CI 1.28-2.81, p = 0.001). CONCLUSION Cortical DWI location was independently associated with transient stroke symptoms <24 h. This may be explained by vessel recanalization, resulting in upstream transportation of remaining particles and distal cortical lesions.
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Ichinose M, Sala-Mercado JA, Coutsos M, Li Z, Ichinose TK, Dawe E, Fano D, O'Leary DS. Dynamic cardiac output regulation at rest, during exercise, and muscle metaboreflex activation: impact of congestive heart failure. Am J Physiol Regul Integr Comp Physiol 2012; 303:R757-68. [PMID: 22855278 DOI: 10.1152/ajpregu.00119.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested whether mild and moderate dynamic exercise and muscle metaboreflex activation (MMA) affect dynamic baroreflex control of heart rate (HR) and cardiac output (CO), and the influence of stroke volume (SV) fluctuations on CO regulation in normal (N) and pacing-induced heart failure (HF) dogs by employing transfer function analyses of the relationships between spontaneous changes in left ventricular systolic pressure (LVSP) and HR, LVSP and CO, HR and CO, and SV and CO at low and high frequencies (Lo-F, 0.04-0.15 Hz; Hi-F, 0.15-0.6 Hz). In N dogs, both workloads significantly decreased the gains for LVSP-HR and LVSP-CO in Hi-F, whereas only moderate exercise also reduced the LVSP-CO gain in Lo-F. MMA during mild exercise further decreased the gains for LVSP-HR in both frequencies and for LVSP-CO in Lo-F. MMA during moderate exercise further reduced LVSP-HR gain in Lo-F. Coherence for HR-CO in Hi-F was decreased by exercise and MMA, whereas that in Lo-F was sustained at a high level (>0.8) in all settings. HF significantly decreased dynamic HR and CO regulation in all situations. In HF, the coherence for HR-CO in Lo-F decreased significantly in all settings; the coherence for SV-CO in Lo-F was significantly higher. We conclude that dynamic exercise and MMA reduces dynamic baroreflex control of HR and CO, and these are substantially impaired in HF. In N conditions, HR modulation plays a major role in CO regulation. In HF, influence of HR modulation wanes, and fluctuations of SV dominate in CO variations.
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Affiliation(s)
- Masashi Ichinose
- Dept. of Physiology, Wayne State Univ. School of Medicine, Detroit, MI 48201, USA
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Affiliation(s)
- Gerd Heusch
- Institut für Pathophysiologie, Universitätsklinikum Essen
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Ichinose M, Sala-Mercado JA, O'Leary DS, Hammond RL, Coutsos M, Ichinose T, Pallante M, Iellamo F. Spontaneous baroreflex control of cardiac output during dynamic exercise, muscle metaboreflex activation, and heart failure. Am J Physiol Heart Circ Physiol 2008; 294:H1310-6. [PMID: 18192212 DOI: 10.1152/ajpheart.01187.2007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously shown that spontaneous baroreflex-induced changes in heart rate (HR) do not always translate into changes in cardiac output (CO) at rest. We have also shown that heart failure (HF) decreases this linkage between changes in HR and CO. Whether dynamic exercise and muscle metaboreflex activation (via imposed reductions in hindlimb blood flow) further alter this translation in normal and HF conditions is unknown. We examined these questions using conscious, chronically instrumented dogs before and after pacing-induced HF during mild and moderate dynamic exercise with and without muscle metaboreflex activation. We measured left ventricular systolic pressure (LVSP), CO, and HR and analyzed the spontaneous HR-LVSP and CO-LVSP relationships. In normal animals, mild exercise significantly decreased HR-LVSP (-3.08 +/- 0.5 vs. -5.14 +/- 0.6 beats.min(-1).mmHg(-1); P < 0.05) and CO-LVSP (-134.74 +/- 24.5 vs. -208.6 +/- 22.2 ml.min(-1).mmHg(-1); P < 0.05). Moderate exercise further decreased both and, in addition, significantly reduced HR-CO translation (25.9 +/- 2.8% vs. 52.3 +/- 4.2%; P < 0.05). Muscle metaboreflex activation at both workloads decreased HR-LVSP, whereas it had no significant effect on CO-LVSP and the HR-CO translation. HF significantly decreased HR-LVSP, CO-LVSP, and the HR-CO translation in all situations. We conclude that spontaneous baroreflex HR responses do not always cause changes in CO during exercise. Moreover, muscle metaboreflex activation during mild and moderate dynamic exercise reduces this coupling. In addition, in HF the HR-CO translation also significantly decreases during both workloads and decreases even further with muscle metaboreflex activation.
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Affiliation(s)
- Masashi Ichinose
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Sala-Mercado JA, Ichinose M, Hammond RL, Coutsos M, Ichinose T, Pallante M, Iellamo F, O'Leary DS. Spontaneous baroreflex control of heart rate versus cardiac output: altered coupling in heart failure. Am J Physiol Heart Circ Physiol 2008; 294:H1304-9. [PMID: 18192213 DOI: 10.1152/ajpheart.01186.2007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dynamic cardiac baroreflex responses are frequently investigated by analyzing the spontaneous reciprocal changes in arterial pressure and heart rate (HR). However, whether the spontaneous baroreflex-induced changes in HR translate into changes in cardiac output (CO) is unknown. In addition, this linkage between changes in HR and changes in CO may be different in subjects with heart failure (HF). We examined these questions using conscious dogs before and after pacing-induced HF. Spontaneous baroreflex sensitivity in the control of HR and CO was evaluated as the slopes of the linear relationships between HR or CO and left ventricular systolic pressure (LVSP) during spontaneous sequences of greater or equal to three consecutive beats when HR or CO changed inversely versus pressure. Furthermore, the translation of baroreflex HR responses into CO responses (HR-CO translation) was examined by computing the overlap between HR and CO sequences. In normal resting conditions, 44.0 +/- 4.4% of HR sequences overlapped with CO sequences, suggesting that only around half of the baroreflex HR responses cause CO responses. In HF, HR-LVSP, CO-LVSP, and the HR-CO translation significantly decreased compared with the normal condition (-2.29 +/- 0.5 vs. -5.78 +/- 0.7 beats.min(-1).mmHg(-1); -70.95 +/- 11.8 vs. -229.89 +/- 29.6 ml.min(-1).mmHg(-1); and 19.66 +/- 4.9 vs. 44.0 +/- 4.4%, respectively). We conclude that spontaneous baroreflex HR responses do not always cause changes in CO. In addition, HF significantly decreases HR-LVSP, CO-LVSP, and HR-CO translation.
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Affiliation(s)
- Javier A Sala-Mercado
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Nishijima Y, Sridhar A, Viatchenko-Karpinski S, Shaw C, Bonagura JD, Abraham WT, Joshi MS, Bauer JA, Hamlin RL, Györke S, Feldman DS, Carnes CA. Chronic cardiac resynchronization therapy and reverse ventricular remodeling in a model of nonischemic cardiomyopathy. Life Sci 2007; 81:1152-9. [PMID: 17884106 PMCID: PMC2080080 DOI: 10.1016/j.lfs.2007.08.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/06/2007] [Accepted: 08/08/2007] [Indexed: 11/30/2022]
Abstract
While cardiac resynchronization therapy (CRT) has been shown to reduce morbidity and mortality in heart failure (HF) patients, the fundamental mechanisms for the efficacy of CRT are poorly understood. The lack of understanding of these basic mechanisms represents a significant barrier to our understanding of the pathogenesis of HF and potential recovery mechanisms. Our purpose was to determine cellular mechanisms for the observed improvement in chronic HF after CRT. We used a canine model of chronic nonischemic cardiomyopathy. After 15 months, dogs were randomized to continued RV tachypacing (untreated HF) or CRT for an additional 9 months. Six minute walk tests, echocardiograms, and electrocardiograms were done to assess the functional response to therapy. Left ventricular (LV) midmyocardial myocytes were isolated to study electrophysiology and intracellular calcium regulation. Compared to untreated HF, CRT improved HF-induced increases in LV volumes, diameters and mass (p<0.05). CRT reversed HF-induced prolongations in LV myocyte repolarization (p<0.05) and normalized HF-induced depolarization (p<0.03) of the resting membrane potential. CRT improved HF-induced reductions in calcium (p<0.05). CRT did not attenuate the HF-induced increases in LV interstitial fibrosis. Using a translational approach in a chronic HF model, CRT significantly improved LV structure; this was accompanied by improved LV myocyte electrophysiology and calcium regulation. The beneficial effects of CRT may be attributable, in part, to improved LV myocyte function.
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Affiliation(s)
- Yoshinori Nishijima
- Department of Veterinary Biosciences, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Arun Sridhar
- Biophysics Program, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Serge Viatchenko-Karpinski
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Courtney Shaw
- Department of Veterinary Biosciences, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - John D Bonagura
- Department of Veterinary Clinical Sciences, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - William T. Abraham
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
- Division of Cardiovascular Medicine, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Mandar S. Joshi
- College of Pharmacy, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
- Columbus Children’s Research Institute, Columbus, OH
| | - John Anthony Bauer
- College of Pharmacy, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
- Columbus Children’s Research Institute, Columbus, OH
| | - Robert L. Hamlin
- Department of Veterinary Biosciences, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Sandor Györke
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - David S. Feldman
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
- Division of Cardiovascular Medicine, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Cynthia A. Carnes
- Biophysics Program, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
- College of Pharmacy, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
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Sala-Mercado JA, Hammond RL, Kim JK, McDonald PJ, Stephenson LW, O'Leary DS. Heart failure attenuates muscle metaboreflex control of ventricular contractility during dynamic exercise. Am J Physiol Heart Circ Physiol 2007; 292:H2159-66. [PMID: 17189347 DOI: 10.1152/ajpheart.01240.2006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Underperfusion of active skeletal muscle elicits a reflex pressor response termed the muscle metaboreflex (MMR). In normal dogs during mild exercise, MMR activation causes large increases in cardiac output (CO) and mean arterial pressure (MAP); however, in heart failure (HF) although MAP increases, the rise in CO is virtually abolished, which may be due to an impaired ability to increase left ventricular contractility (LVC). The objective of the present study was to determine whether the increases in LVC seen with MMR activation during dynamic exercise in normal animals are abolished in HF. Conscious dogs were chronically instrumented to measure CO, MAP, and left ventricular (LV) pressure and volume. LVC was calculated from pressure-volume loop analysis [LV maximal elastance ( Emax) and preload-recruitable stroke work (PRSW)] at rest and during mild and moderate exercise under free-flow conditions and with MMR activation (via partial occlusion of hindlimb blood flow) before and after rapid ventricular pacing-induced HF. In control experiments, MMR activation at both workloads [mild exercise (3.2 km/h) and moderate exercise (6.4 km/h at 10% grade)] significantly increased CO, Emax, and PRSW. In contrast, after HF was induced, CO, Emax, and PRSW were significantly lower at rest. Although CO increased significantly from rest to exercise, Emax and PRSW did not change. In addition, MMR activation caused no significant change in CO, Emax, or PRSW at either workload. We conclude that MMR causes large increases in LVC in normal animals but that this ability is abolished in HF.
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Affiliation(s)
- Javier A Sala-Mercado
- Department of Physiology, Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, MI 48201, USA
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14
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Abstract
The term tachycardia-induced cardio-myopathy or tachycardiomyopathy refers to impairment in left ventricular function secondary to chronic tachycardia, which is partially or completely reversible once the tachyarrhythmia is controlled. Tachycardia-induced cardiomyopathy has been shown to occur both in experimental models and in patients with incessant tachyarrhythmia. Data from several studies and from case reports have shown that rate control by means of cardioversion, negative chronotropic agents, and surgical or catheter-based atrio-ventricular node ablation, resulted in significant improvement of systolic function. The diagnosis of tachycardia-induced cardiomyopathy is usually made following observation of marked improvement in systolic function after normalization of heart rate. Clinicians should be aware that patients with unexplained systolic dysfunction may have tachycardia-induced cardiomyo-pathy, and that controlling the arrhythmia may result in improvement of systolic function.
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Affiliation(s)
- Hassan A Mohamed
- Department of Medicine, Division of Cardiology, Regina General Hospital, Regina, SK, Canada
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15
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Abstract
Heart failure is the major cause of mortality in Western countries. Medical treatment of heart failure is associated with 50% survival at 5 years. Experimental models are required to better understand the progression of the disease and elaborate new therapy. Heart transplantation, left ventricular assist devices, artificial hearts, and cardiac bioassist techniques require animal models for testing and optimizing before they are implemented on human patients. The perfect model of heart failure that reproduces every aspect of the natural disease does not exist. Acute and chronic heart failure models have been developed to reproduce different aspect of the pathology.
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Affiliation(s)
- Eric Monnet
- Department of Clinical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
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16
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Watanabe K, Kuroda H, Sato E, Makino H. In vivo evaluation of the improved MCMS-0102 pacemaker with a rapid pacing mode for induction of experimental heart failure in animals. J Artif Organs 2006; 9:84-9. [PMID: 16807810 DOI: 10.1007/s10047-006-0328-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Accepted: 01/11/2006] [Indexed: 10/24/2022]
Abstract
The MCMS-0102 cardiac pacemaker for rapid ventricular pacing to induce heart failure in animals has been improved in terms of miniaturization and performance. To determine the performance of the new MCMS-0102, six devices were implanted in beagle dogs, and two of these devices were reimplanted for continued pacing in a total of eight beagle dogs. The hearts were paced at 260 beats per minute for 4 weeks (P group: n = 8). The hemodynamic status of the P group was examined and compared with nonpaced dogs (NP group: n = 8). The neurohumoral status of the P group was evaluated before and after rapid pacing. Stable operation of the six devices during rapid pacing was confirmed using the telemetry system. Postmortem examinations revealed features similar to clinical heart failure characterized by massive ascites, pleural effusion, cardiomegaly, and liver congestion in all the paced dogs. Cardiac output was 1.1 +/- 0.2 l/min in the NP group and 0.5 +/- 0.1 l/min in the P group (P < 0.0001). The left atrial pressure and the central venous pressure of the P group and the NP group were 23 +/- 6 versus 6 +/- 2 mmHg (P < 0.0001) and 10 +/- 3 versus 4 +/- 3 mmHg (P < 0.001), respectively. In the paced dogs, plasma renin activity increased from 0.5 +/- 0.4 to 8.5 +/- 7.4 ng/ml/h (P < 0.05) and atrial natriuretic peptide levels increased from 69 +/- 41 to 229 +/- 72 pg/ml (P < 0.001). The improved MCMS-0102 was successfully implanted in beagle dogs and it succeeded in inducing the congestive heart failure model.
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Affiliation(s)
- Kuniyoshi Watanabe
- Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
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17
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Nishijima Y, Feldman DS, Bonagura JD, Ozkanlar Y, Jenkins PJ, Lacombe VA, Abraham WT, Hamlin RL, Carnes CA. Canine nonischemic left ventricular dysfunction: a model of chronic human cardiomyopathy. J Card Fail 2006; 11:638-44. [PMID: 16230269 DOI: 10.1016/j.cardfail.2005.05.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Revised: 04/27/2005] [Accepted: 05/13/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND The mechanisms of cardiac remodeling during chronic heart failure remain poorly defined. We sought to advance a chronic canine model of nonischemic cardiomyopathy. METHODS AND RESULTS Male dogs (n = 6) received decremental right ventricular apical tachypacing (12 months) to achieve and maintain stable left ventricular (LV) dysfunction. After 10 months of tachypacing, 120 beats/min was sufficient to maintain stable LV dysfunction. Electrocardiography, echocardiography, and tissue Doppler imaging were done to evaluate electrophysiology, LV dimensions and function, and dyssynchrony during normal sinus rhythm. The 6-minute walk test was used to evaluate functional capacity. We observed increases in both QRS duration (P < .0001) and QRS amplitude (P < .0001). LV fractional shortening was reduced from a baseline of 38.0 +/- 1.4% to 11.2 +/- 1.4% (P < .0001). LV end-diastolic dimension increased from 3.8 +/- 0.1 cm at baseline to 5.3 +/- 0.3 cm (P < .0001); LV end-systolic dimension increased from 2.3 +/- 0.1 cm to 4.7 +/- 0.2 cm (P < .0001). LV mass increased from 85.9 +/- 3.5 g at baseline to 179 +/- 13.7 g (P < .0001). There was evidence of LV dyssynchrony (P < .04) during both normal sinus rhythm and right ventricular tachypacing, compared with control dogs. The distance a dog walked in 6 minutes was significantly less at 12 months compared with normal controls (540 +/- 32 m versus 277 +/- 64 m, P < .008). CONCLUSION This nonischemic model of canine cardiomyopathy reproduces many aspects of chronic human heart failure including reduced fractional shortening, dilated ventricular dimensions, increased LV mass, decreased functional capacity, and dyssynchrony.
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Affiliation(s)
- Yoshinori Nishijima
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA
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18
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Issa ZF, Rosenberger J, Groh WJ, Miller JM, Zipes DP. Ischemic ventricular arrhythmias during heart failure: A canine model to replicate clinical events. Heart Rhythm 2005; 2:979-83. [PMID: 16171754 DOI: 10.1016/j.hrthm.2005.06.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Accepted: 06/17/2005] [Indexed: 11/20/2022]
Abstract
BACKGROUND Development of experimental animal models has played an invaluable role in understanding the mechanisms of ventricular arrhythmias. OBJECTIVES The purpose of this study was to evaluate a new canine model of myocardial infarction (MI), heart failure, and ischemic ventricular arrhythmias in an attempt to replicate clinical conditions. METHODS Thirty-six mongrel dogs underwent placement of a permanent ventricular pacemaker and induction of an anterior MI by percutaneous transcatheter embolization of polyvinyl foam particles into the left anterior descending coronary artery (just distal to the first septal branch). After a 2-week recovery period, heart failure was induced by continuous rapid ventricular pacing at 200 to 240 ppm for 3 weeks. Transient (4-minute) myocardial ischemia was induced via balloon occlusion of the proximal left circumflex coronary artery. Echocardiographic and electrophysiologic testing was performed before MI creation and repeated prior to acute ischemia induction. RESULTS Seven dogs (19%) died within several hours of MI creation. All surviving dogs developed severe left ventricular systolic dysfunction. Significant increases in the intraatrial and intraventricular conduction intervals were observed following MI creation and heart failure induction compared with baseline values, as evidenced by increases in the duration of the P wave and QRS complex. Significant increases in corrected QT interval and ventricular refractoriness were observed. Acute transient ischemia induced sustained ventricular tachycardia or ventricular fibrillation in 21 of 29 dogs (72%). CONCLUSION This canine model can serve as a useful tool for studying ventricular arrhythmias during the interactions of healed infarction, heart failure, increased sympathetic tone, and myocardial ischemia.
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Affiliation(s)
- Ziad F Issa
- Krannert Institute of Cardiology, Indiana University, Indianapolis, Indiana 46202, USA
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Feindt P, Litmathe J, Boeken U, Gams E. Reverse remodeling by net cardioplasty in a model of dilated cardiomyopathy: results of an animal study. Int J Artif Organs 2004; 27:891-7. [PMID: 15560683 DOI: 10.1177/039139880402701010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM End-stage heart failure is a growing clinical problem with only a few satisfactory therapeutical options. Dilated cardiomyopathy (DCM) is associated with a progressive decline in cardiac function. Our hypothesis was to arrest this worsening of cardiac function by mechanically containing the dilated heart with a special net. METHODS In 16 pigs (50+/-7 kg) DCM congestive heart failure was initiated by rapid ventricular pacing (220 b/m). In series 1 (n=8) a polyester net was placed around both ventricles before pacing was induced, whereas in series 2 (n=8) ventricular wrapping was performed when DCM was established. RESULTS Comparing hemodynamic data before re-operation of group 11-animals, the decrease of CO and dp/dt(max) was significantly lower in series 1 than in series 2 compared to the baseline values before pacing (CO: series 1:-22.6+/-3.3%, series 2:-52.4+/-6.4%, p<0.05; dp/dt: series 1: +16.4+/-2.8%, series 2: -51.5+/-5.9%, p<0.05). In series 2, after net implantation, we could furthermore show that deterioration of the animal stopped and hemodynamic data improved significantly in the following 2 weeks (CO: +62.9+/-10.5% and dp/dt +37.0+/-6.8%). CONCLUSION Ventricular containment with a polyester net seems to be a therapeutic option in cardiac insuffiency caused by ventricular dilation. This cardioplasty induced a reverse remodeling of the dilated hearts with a significant improvement in diastolic and systolic ventricular function.
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Affiliation(s)
- P Feindt
- Department of Thoracic and Cardiovascular Surgery, Heinrich Heine University, Düsseldorf - Germany
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Tessier D, Lajos P, Braunberger E, Pouchelon JL, Carpentier A, Chachques JC, Chetboul V. Induction of chronic cardiac insufficiency by arteriovenous fistula and doxorubicin administration. J Card Surg 2003; 18:307-11. [PMID: 12869175 DOI: 10.1046/j.1540-8191.2003.02044.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Large animal experimental models of chronic heart failure (HF) permit repeated invasive assessment of cardiovascular function, and evaluation of new medical or surgical therapies. The existing models however fail to achieve stable and long-term HF. The aim of this study was to create a simple and stable chronic model of HF in goat, using both arteriovenous fistula and weekly intravenous doxorubicin injections. METHODS After a preliminary experiment on four goats receiving weekly 1 to 2 mg/kg of doxorubicin, six adult female goats, having had an arteriovenous fistula without signs or symptoms of heart failure, received weekly two different dosages of doxorubicin for 13 weeks: group A (n = 3) received 0.5 mg/kg and group B (n = 3) received 1 mg/kg. After a three-month period without medication, both groups received again 1 mg/kg for four weeks. Cardiac function was assessed by repeated electrocardiographic and echocardiographic examinations. RESULTS Four goats died during the medication period (one in group A, three in group B). During the period without medication a stable ventricular hypocontractility with left ventricular dilation was observed. Left ventricular dysfunction was more pronounced in group B, and was associated with clinical symptoms of HF. CONCLUSIONS Arteriovenous fistula alone did not produce HF. Its association with doxorubicin injections provides a simple and stable chronic model of HF. This association allows reduction of the required doxorubicin dose and toxicity in animals and in the environment. Depending of the dose of doxorubicin, it is possible to obtain a model of heart dilatation and ventricular hypokinesia with or without clinical symptoms of HF, with a different mortality.
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Tibayan FA, Lai DTM, Timek TA, Dagum P, Liang D, Daughters GT, Ingels NB, Miller DC. Alterations in left ventricular torsion in tachycardia-induced dilated cardiomyopathy. J Thorac Cardiovasc Surg 2002; 124:43-9. [PMID: 12091807 DOI: 10.1067/mtc.2002.121299] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Left ventricular torsion reduces transmural systolic gradients of fiber strain, and torsional recoil in early diastole is thought to enhance left ventricular filling. Left ventricular remodeling in dilated cardiomyopathy may result in changes in torsion dynamics, but these effects are not yet characterized. Tachycardia-induced cardiomyopathy is accompanied by systolic and diastolic heart failure and left ventricular remodeling. We hypothesized that cardiomyopathy would alter systolic and diastolic left ventricular torsion mechanics, and this hypothesis was tested by studying sheep before and after the development of tachycardia-induced cardiomyopathy. METHODS Implanted miniature radiopaque markers were used in 8 sheep to measure left ventricular geometry and function, maximal torsional deformation, and early diastolic recoil before and after rapid ventricular pacing was used to create tachycardia-induced cardiomyopathy. RESULTS All animals had significant heart failure with ventricular dilatation and remodeling. With tachycardia-induced cardiomyopathy, maximum torsion relative to control conditions decreased (1.69 degrees +/- 0.61 degrees vs 4.25 degrees +/- 2.33 degrees ), and early diastolic recoil was completely abolished (0.53 degrees +/- 1.19 degrees vs -1.17 degrees +/- 0.94 degrees ). CONCLUSIONS Cardiomyopathy is accompanied by decreased and delayed systolic left ventricular torsional deformation and loss of early diastolic recoil, which may contribute to left ventricular dysfunction by increasing systolic transmural strain gradients and impairing diastolic filling. Analysis of left ventricular torsion with radiofrequency-tagging magnetic resonance imaging should be explored to elucidate the role of torsion in patients with cardiomyopathy.
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Affiliation(s)
- Frederick A Tibayan
- Department of Cardiovascular and Thoracic Surgery, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305-5247, USA
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22
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Takagaki M, McCarthy PM, Tabata T, Dessoffy R, Cardon LA, Connor J, Ochiai Y, Thomas JD, Francis GS, Young JB, Fukamachi K. Induction and maintenance of an experimental model of severe cardiomyopathy with a novel protocol of rapid ventricular pacing. J Thorac Cardiovasc Surg 2002; 123:544-9. [PMID: 11882829 DOI: 10.1067/mtc.2002.118276] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE An animal model of chronic severe heart failure is needed to evaluate new mechanical devices, surgical procedures, and medical therapies. The purpose of this study was to evaluate a unique new model of severe heart failure developed by means of a novel protocol of rapid ventricular pacing. METHODS Heart failure was induced in 8 mongrel dogs by means of rapid ventricular pacing (230 beats/min) for 4 weeks. After a sham operation, maintenance pacing at a reduced rate (190 beats/min) was continued for another 4 weeks. RESULTS Left ventricular systolic function was significantly reduced at week 4 and remained low at week 8, including the slope of the end-systolic pressure-volume relationship (2.4 +/- 1.0 vs 0.7 +/- 0.2 vs 0.8 +/- 0.3 mm Hg/mL [baseline vs week 4 vs week 8, respectively]), ejection fraction (63% +/- 5% vs 28% +/- 7% vs 33% +/- 5%), and cardiac output (3.1 +/- 0.7 vs 2.0 +/- 0.3 vs 2.2 +/- 0.7 L/min). Significant ventricular remodeling changes took place with increased ventricular volumes and circumferential wall stress, which were stable between weeks 4 and 8. Serum catecholamine and atrial natriuretic polypeptide levels also increased from baseline but stabilized between weeks 4 and 8. The end-diastolic pressure-volume relationship also showed stable diastolic function between weeks 4 and 8. CONCLUSIONS Induction pacing at 230 beats/min readily created severe heart failure in all animals, and a new technique of maintenance pacing provided a consistent model of severe heart failure. This model can be used to study a variety of new interventions for heart failure.
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Affiliation(s)
- Masami Takagaki
- Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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Patel BG, Shah SH, Astra LI, Hammond RL, Sharif ZA, McDonald PJ, Stephenson LW. Skeletal muscle ventricle aortic counterpulsation: function during chronic heart failure. Ann Thorac Surg 2002; 73:588-93. [PMID: 11845879 DOI: 10.1016/s0003-4975(01)03458-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Skeletal muscle ventricles (SMVs) are pumping chambers formed from latissimus dorsi muscle. The SMV aortic counterpulsator model has been proven to be stable in the long term and provide effective diastolic pressure augmentation in normal dogs. This study seeks to prove that the aortic counterpulsator model can function effectively in chronic heart failure. METHODS In 6 dogs, pericardium-lined SMVs were created from latissimus dorsi muscle and electrically conditioned for fatigue resistance. Each SMV was attached to the descending thoracic aorta with a two-limb bifurcated graft and the aorta ligated between the limbs. The SMV was stimulated to contract during cardiac diastole at 1:2 to 1:3 ratio. Rapid ventricular pacing was initiated at 220 to 230 beats/min for 7 weeks to induce chronic heart failure. RESULTS SMV contraction resulted in augmentation of the diastolic pressure time-index by 12.1% (32.8+/-15.4 versus 36.1+/-14.7 mm Hg-s, p < 0.05) at baseline, then by 33.6% (12.9+/-4.4 versus 16.8+/-4.3 mm Hg-s, p < 0.05) after 7 weeks of rapid ventricular pacing. After 7 weeks of rapid ventricular pacing, SMV counterpulsation provided significant afterload reduction with increases in peak left ventricular ejection velocity and stroke volume of 22.7% (142+/-55 versus 168+/-45 mL/s, p < 0.05) and 6.2% (13.0+/-5.1 versus 13.7+/-5.2 mL, p < 0.05), respectively. Coronary blood flow was measured in 3 animals at the 7-week measurement; augmentation averaged 47.6% (0.357+/-0.29 versus 0.432+/-0.26 mL/beat, p < 0.05). CONCLUSIONS The SMV aortic counterpulsator provides improved cardiac assistance relative to the failing heart.
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Affiliation(s)
- Bhavik G Patel
- Department of Surgery, Wayne State University, Detroit, Michigan, USA
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Watanabe K, Kuroda H, Sato E, Makino H, Hasegawa Y, Amano J. Heart failure in the dog induced by rapid ventricular pacing using a newly designed cardiac pacemaker, MCMS-0102. J Artif Organs 2001. [DOI: 10.1007/bf02479899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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