Project description:CRT is a cornerstone of therapy for patients with heart failure and reduced ejection fraction. By restoring left ventricular (LV) electrical and mechanical synchrony, CRT can reduce mortality, improve LV function and reduce heart failure symptoms. Since its introduction, many advances have been made that have improved the delivery of and enhanced the response to CRT. Improving CRT outcomes begins with proper patient selection so CRT is delivered to all populations that could benefit from it, and limiting the implantation of CRT in those with a small chance of response. In addition, advancements in LV leads and delivery technologies coupled with multimodality imaging and electrical mapping have enabled operators to place coronary sinus leads in locations that will optimise electrical and mechanical synchrony. Finally, new pacing strategies using LV endocardial pacing or His bundle pacing have allowed for CRT delivery and improved response in patients with poor coronary sinus anatomy or lack of response to traditional CRT.
Project description:Arrhythmia is an extremely common finding in patients receiving cardiac resynchronisation therapy (CRT). Despite this, in the majority of randomised trials testing CRT efficacy, patients with a recent history of arrhythmia were excluded. Most of our knowledge into the management of arrhythmia in CRT is therefore based on arrhythmia trials in the heart failure (HF) population, rather than from trials dedicated to the CRT population. However, unique to CRT patients is the aim to reach as close to 100% biventricular pacing (BVP) as possible, with HF outcomes greatly influenced by relatively small changes in pacing percentage. Thus, in comparison to the average HF patient, there is an even greater incentive for controlling arrhythmia, to achieve minimal interference with the effective delivery of BVP. In this review, we examine both atrial and ventricular arrhythmias, addressing their impact on CRT, and discuss the available evidence regarding optimal arrhythmia management in this patient group. We review pharmacological and procedural-based approaches, and lastly explore novel ways of harnessing device data to guide treatment of arrhythmia in CRT.
Project description:We report the case of a man in his 60s who had dilated cardiomyopathy with severe functional mitral regurgitation. Four years after a cardiac resynchronization therapy (CRT) device with an implantable cardioverter defibrillator was implanted, this device was replaced with an adaptive CRT device because of battery consumption. Seven months after replacement of this device, the left ventricular pacing to right ventricular activation and the atrioventricular delay from automatic adjustments contributed to less functional mitral regurgitation. The findings from our case suggest that optimal CRT, by measuring intracardiac conduction parameters, is effective for functional mitral regurgitation.
Project description:IntroductionOlder patients may be less likely to receive cardiac resynchronisation therapy (CRT) for the management of heart failure. We aimed to describe the differences in clinical response, complications, and subsequent outcomes following CRT implantation compared to younger patients.MethodsWe conducted a retrospective cohort study of unselected, consecutive patients implanted with CRT devices between March 2008 and July 2017. We recorded complications, symptomatic and echocardiographic response, hospitalisation for heart failure, and all-cause mortality comparing patients aged <70, 70-79 and ≥ 80 years.ResultsFive hundred and seventy-four patients (median age 76 years [interquartile range 68-81], 73.3% male) received CRT. At baseline, patients aged ≥80 years had worse symptoms, were more likely to have co-morbidities, and less likely to be receiving comprehensive medical therapy, although left ventricular function was similar. Older patients were less likely to receive CRT-defibrillators compared to CRT-pacemakers. Complications were infrequent and not more common in older patients. Age was not a predictor of symptomatic or echocardiographic response to CRT (67.2%, 71.2% and 62.6% responders in patients aged <70, 70-79 and ≥ 80 years, respectively; P = 0.43), and time to first heart failure hospitalisation was similar across age groups (P = 0.28). Ten-year survival was lower for older patients (49.9%, 23.9% and 6.8% in patients aged <70, 70-79 and ≥ 80 years, respectively; P < 0.001).ConclusionsThe benefits of CRT on symptoms and left ventricular function were not different in older patients despite a greater burden of co-morbidities and less optimal medical therapy. These findings support the use of CRT in an ageing population.
Project description:Dilated cardiomyopathy is a serious and life-threatening disorder in children. It is the most common form of pediatric cardiomyopathy. Therapy for this condition has varied little over the last several decades and mortality continues to be high. Currently, children with dilated cardiomyopathy are treated with pharmacological agents and mechanical support, but most require heart transplantation and survival rates are not optimal. The lack of common treatment guidelines and inadequate survival rates after transplantation necessitates more therapeutic clinical trials. Stem cell and cell-based therapies offer an innovative approach to restore cardiac structure and function towards normal, possibly reducing the need for aggressive therapies and cardiac transplantation. Mesenchymal stem cells and cardiac stem cells may be the most promising cell types for treating children with dilated cardiomyopathy. The medical community must begin a systematic investigation of the benefits of current and novel treatments such as stem cell therapies for treating pediatric dilated cardiomyopathy.
Project description:This article contains supplemental data to the publication "Central Sleep Apnea and Pacing-Induced Cardiomyopathy" [1], which was the most recent publication of the "UPGRADE" study. It provides in-depth analysis of the effects of cardiac resynchronisation therapy (CRT) in patients suffering from pacing-induced cardiomyopathy (PICM) on cardiac remodeling as well as functional cardiac parameters in comparison to continuous right ventricular pacing (RVP). Furthermore, it also covers additional data on several sleep parameters, which were not presented in the main article including the index for obstructive sleep apnea (OSA), the index for mixed sleep apnea and the oxygen saturation measurements during polysomnography. Further, Kaplan-Meier curves are presented for major adverse cardiac events (MACE) and overall mortality by severity of sleep apnea. Generally, the "UGRADE" study was a single-center prospective double-blinded randomized controlled trial lasting from 2014 to 2020. The methodology included a cross-over design giving the possibility to detect differences while CRT was activated and while continuous RVP was applied. The presented data should aid clinicians in daily practice as upgrading to CRT is not limited to improvement in cardiac parameters, but also modifies sleep apnea in patients with PICM, a generally sparsely studied entity of heart failure.
Project description:To investigate the physiological characteristics of cardiac fibroblasts (CF) from pediatric dilated cardiomyopathy (DCM) patients, CFs were harvested from left ventricular free wall at the heart transplantation. We then performed RNA-seq for 7 different lines of CFs.
Project description:Current guidelines recommend cardiac resynchronisation therapy (CRT) for patients with severe left ventricular dysfunction (left ventricular ejection fraction [LVEF] ?35 %), QRS duration of ?120-150 ms (Class IA and IB indications) on surface electrocardiogram (ECG) and New York Heart Association (NYHA) class III or IV heart failure (HF) symptoms. Ongoing studies aim to expand the use of CRT in patients with asymptomatic or minimal symptoms left ventricular dysfunction. There have been studies that have shown benefit of CRT extended to this group of patients. There have also been different implications of the role of CRT in patients with atrial fibrillation (AF), patients with narrow QRS duration or with right bundle branch block (RBBB) on surface ECG, as well as patients with end-stage renal failure on dialysis therapy. This article aims to review the current body of evidence of expanding use of CRT in these populations.
Project description:BackgroundGenetic studies of cardiomyopathy and heart failure have limited throughput in mammalian models. Adult zebrafish have been recently pursued as a vertebrate model with higher throughput, but genetic conservation must be tested.Methods and resultsWe conducted transcriptome analysis of zebrafish heart and searched for fish homologues of 51 known human dilated cardiomyopathy-associated genes. We also identified genes with high cardiac expression and genes with differential expression between embryonic and adult stages. Among tested genes, 30 had a single zebrafish orthologue, 14 had 2 homologues, and 5 had ≥3 homologues. By analyzing the expression data on the basis of cardiac abundance and enrichment hypotheses, we identified a single zebrafish gene for 14 of 19 multiple-homologue genes and 2 zebrafish homologues of high priority for ACTC1. Of note, our data suggested vmhc and vmhcl as functional zebrafish orthologues for human genes MYH6 and MYH7, respectively, which are established molecular markers for cardiac remodeling.ConclusionsMost known genes for human dilated cardiomyopathy have a corresponding zebrafish orthologue, which supports the use of zebrafish as a conserved vertebrate model. Definition of the cardiac transcriptome and fetal gene program will facilitate systems biology studies of dilated cardiomyopathy in zebrafish.