scholarly journals Cardiac Resynchronisation Therapy and Cellular Bioenergetics: Effects Beyond Chamber Mechanics

2019 ◽  
Vol 14 (1) ◽  
pp. 33-44
Author(s):  
Christos-Konstantinos Antoniou ◽  
Panagiota Manolakou ◽  
Nikolaos Magkas ◽  
Konstantinos Konstantinou ◽  
Christina Chrysohoou ◽  
...  

Cardiac resynchronisation therapy is a cornerstone in the treatment of advanced dyssynchronous heart failure. However, despite its widespread clinical application, precise mechanisms through which it exerts its beneficial effects remain elusive. Several studies have pointed to a metabolic component suggesting that, both in concert with alterations in chamber mechanics and independently of them, resynchronisation reverses detrimental changes to cellular metabolism, increasing energy efficiency and metabolic reserve. These actions could partially account for the existence of responders that improve functionally but not echocardiographically. This article will attempt to summarise key components of cardiomyocyte metabolism in health and heart failure, with a focus on the dyssynchronous variant. Both chamber mechanics-related and -unrelated pathways of resynchronisation effects on bioenergetics – stemming from the ultramicroscopic level – and a possible common underlying mechanism relating mechanosensing to metabolism through the cytoskeleton will be presented. Improved insights regarding the cellular and molecular effects of resynchronisation on bioenergetics will promote our understanding of non-response, optimal device programming and lead to better patient care.

2010 ◽  
Vol 6 (1) ◽  
pp. 83
Author(s):  
Jagmeet P Singh ◽  

Cardiac resynchronisation therapy (CRT) has gained widespread acceptance as a safe and effective therapeutic strategy for congestive heart failure (CHF) refractory to optimal medical therapy. The use of implantable devices has substantially altered the natural history of systolic heart failure. These devices exert their physiological impact through ventricular remodelling, associated with a reduction in left ventricular (LV) volumes and an improvement in ejection fraction (EF). Several prospective randomised studies have shown that this in turn translates into long-term clinical benefits such as improved quality of life, increased functional capacity and reduction in hospitalisation for heart failure and overall mortality. Despite these obvious benefits, there remain more than a few unresolved concerns, the most important being that up to one-third of patients treated with CRT do not derive any detectable benefit. There are several determinants of successful delivery and response to CRT, including selecting the appropriate patient, patient-specific optimal LV pacing lead placement and appropriate post-implant device care and follow-up. This article highlights the importance of collectively working on all of these aspects of CRT to enhance and maximise response.


2009 ◽  
Vol 5 (1) ◽  
pp. 41
Author(s):  
Michalis Efremidis ◽  

There is a sinister synergism between atrial fibrillation (AF) and heart failure (HF). These common cardiovascular conditions often co-exist and result in significant morbidity and mortality. Despite the extensive amount of research and literature about each of these disorders separately, randomised controlled clinical trial data concerning the management of AF in patients with HF are lacking. The recently published Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial elucidated the matter of rhythm versus rate control. In addition, non-pharmacological treatment approaches such as catheter ablation of AF and cardiac resynchronisation therapy are rapidly growing and are likely to alter AF management in HF patients in the near future.


2011 ◽  
Vol 7 (1) ◽  
pp. 29
Author(s):  
Charlotte Eitel ◽  
Gerhard Hindricks ◽  
Christopher Piorkowski ◽  
◽  
◽  
...  

Cardiac resynchronisation therapy (CRT) is an efficacious and cost-effective therapy in patients with highly symptomatic systolic heart failure and delayed ventricular conduction. Current guidelines recommend CRT as a class I indication for patients with sinus rhythm, New York Heart Association (NYHA) functional class III or ambulatory class IV, a QRS duration ≥120ms, and left ventricular ejection fraction (LVEF) ≤35%, despite optimal pharmacological therapy. Recent trials resulted in an extension of current recommendations to patients with mild heart failure, patients with atrial fibrillation, and patients with an indication for permanent right ventricular pacing with the aim of morbidity reduction. The effectiveness of CRT in patients with narrow QRS, patients with end-stage heart failure and cardiogenic shock, and patients with an LVEF >35% still needs to be proved. This article reviews current evidence and clinical applications of CRT in heart failure and provides an outlook on future developments.


Author(s):  
Barbara Dominik ◽  
Mitkowski Przemyslaw ◽  
Wojciech Zorawski ◽  
Ilona Kowalik ◽  
Adam Ciesielski

IntroductionImplantable cardioverter defibrillators register various types of arrhythmias. Thus they can be exploited to better identify patients with atrial fibrillation episodes and increase the proportion of patients who may benefit from implementation of pharmacological prophylaxis of thromboembolic events, most of which it turns out are asymptomatic.Material and methodsAssessment of the frequency, symptoms and predisposing factors for the occurrence of atrial fibrillation episodes in patients with implanted ICD (implantable cardioverter defibrillator) and CRT-D (cardiac resynchronisation therapy with defibrillator) based on the analysis of intracardiac electrocardiograms (IEGM) records. The study included 174 consecutive outpatient cases with heart failure, sinus rhythm and Implanted Cardioverter Defibrillator and Cardiac Resynchronisation Therapy with Defibrillator. Control visits with analysis of IEGM records occurred every three months. During mean follow-up of 20 months, 901 visits were carried out. 147 patients had at least one year of follow-up.ResultsAtrial fibrillation episodes in the study group occurred in 54 (31.0%) of patients and 71.4% were asymptomatic. Predisposing factors were: history of paroxysmal atrial fibrillation (37.0% vs 13.3%, p ˂ 0.001), atrioventricular conduction abnormalities (42.6% vs. 20.0%, p = 0.002), intraventricular conduction abnormalities (59.3% vs 40.8%, p = 0.02) and more severe mitral regurgitation (7.4% vs 0.8%, p = 0.04). Chronic renal disease was a risk factor for death in the study group. No stroke occurred during the study.ConclusionsEpisodes of paroxysmal AF in patients with systolic heart failure and implanted cardioverter-defibrillator systems are quite common. The majority of the episodes recorded in the study were asymptomatic.


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