Exercise capacity and N-terminal pro-brain natriuretic peptide levels with biventricular vs. right ventricular pacing for atrioventricular block: results from the PREVENT-HF German Substudy

Adverse effects of right ventricular pacing on cardiac function: prevalence, prevention and treatment with physiologic pacing

Right ventricular (RV) pacing is the main treatment modality for patients with advanced atrioventricular (AV) block. Chronic RV pacing can cause cardiac systolic dysfunction and heart failure (HF). In this review, we discuss studies that have shown deleterious effects of chronic RV pacing on systolic cardiac function causing pacing-induced cardiomyopathy (PiCM), heart failure (HF), HF hospitalization, atrial fibrillation (AF) and cardiac mortality. RV apical pacing is the most widely used and studied. Adverse effects of RV pacing appear to be directly related to pacing burden and are worse in patients with pre-existing left ventricular (LV) dysfunction. Chronic RV pacing is also associated with heart failure with preserved ejection fraction (HFpEF). Mechanisms, risk factors, clinical and echocardiographic features, and strategies to minimize RV pacing-induced cardiac dysfunction are discussed in light of the latest data. Studies on biventricular (Bi-V) pacing upgrade in patients who develop RV PiCM, use of alternate RV pacing sites, de novo Bi-V pacing, and physiologic pacing using HIS bundle pacing (HBP) and left bundle area (LBBA) pacing in patients with an anticipated high RV pacing burden are discussed.

Cardiomyopathy Associated with Right Ventricular Apical Pacing-Systematic Review and Meta-Analysis

AIMS

Bradyarrhythmias are potentially life-threatening medical conditions. The most widespread treatment for slow rhythms is artificial ventricular pacing. From the inception of the idea of artificial pacing, ventricular leads were located in the apex of the right ventricle. Right ventricular apical pacing (RVAP) was thought to have a deteriorating effect on left ventricular systolic function. The aim of this study was to systematically assess results of randomized controlled trials to determine the effects of right ventricular apical pacing on left ventricular ejection fraction (LVEF).

METHODS

we systematically searched the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE databases for studies evaluating the influence of RVAP on LVEF. Pooled mean difference (MD) with a 95% confidence interval (CI) was estimated using a random effect model.

RESULTS

14 randomized controlled trials (RCTs) comprising 885 patients were included. In our meta-analysis, RVAP was associated with statistically significant left ventricular systolic function impairment as measured by LVEF. The mean difference between LVEF at baseline and after intervention amounted to 3.35% (95% CI: 1.80-4.91).

CONCLUSION

our meta-analysis confirms that right ventricular apical pacing is associated with progressive deterioration of left ventricular systolic function.

Modalities of ventricular pacing for cardiac resynchronization therapy in patients with heart failure: a meta-analysis and systematic review

INTRODUCTION

This meta-analysis evaluated 14 studies which compared clinical and functional outcomes after different cardiac resynchronization therapy (CRT) modalities.

MATERIAL AND METHODS

Relevant studies were selected from the Medline, PubMed, Cochrane, and Google Scholar databases until June 27^th, 2016. We analyzed and compared the clinical outcomes (peak O₂ consumption and LVEF) and functional outcomes (6-min walk distance and quality of life (SF-36)) of HF patients who received different CRT modalities with outcomes in patients who received conventional univentricular therapy.

RESULTS

There was no significant difference in post-treatment 6-min walking distance between the biventricular (BiV) and left/right univentricular (LUV/RUV) groups (standardized difference in means = 0.049, 95% CI: -0.119 to 0.217, p = 0.566), or between the BiV and triventricular (TriV) groups (standardized difference in means = 0.035, 95% CI: -0.270 to 0.340, p = 0.822). Peak O₂ consumption was comparable between BiV and LUV/RUV groups (standardized difference in means = 0.306, 95% CI: -0.002 to 0.614, p = 0.052). Patients in the TriV group had a significant improvement in LVEF compared to the BiV group (standardized difference in means = 0.647, 95% CI: 0.313 to 0.982, p < 0.001).

CONCLUSIONS

TriV CRT is an attractive alternative to univentricular or BiV pacing for heart failure patients. It is necessary to conduct further large randomized trials to validate our present data.

A new method of building permanent A-V block model: ablating his-bundle potential through femoral artery with pre-implanted biventricular pacemaker

Background

To explore the feasibility of a new method of achieving a permanent A-V block animal model.

Methods

16 beagles were randomly divided into two groups based on the method of their pre-implanted biventricular pacemakers. (1) In the first group (8 beagles), the A-V block model was achieved by ablating his-bundle potential at the site of the left ventricular superior-septum, under the aortic sinus, through femoral artery. (2) In the second group (8 beagles), the A-V block model was achieved by ablating his-bundle potential at the triangle of Koch, through femoral vein. A complete A-V block model was achieved as a standard in this study. The success rates, intraoperative arrhythmias, operative and X-ray exposure time, intraoperative bleeding amount were assessed in this two groups, both animal models were followed up for four weeks and then fasted to monitor myocardial pathological changes.

Results

The success rate of the first group, which with fewer intraoperative arrhythmias, and less operative and X-ray exposure time, was significantly higher than the second group.

Conclusions

Compared with traditional animal method, our new method of ablating his-bundle potential at the left ventricle from the femoral artery has a higher success rate, fewer occurrence of malignant arrhythmias, and less operation and X-ray time. Thus, our new method should be preferred in the building of Permanent A-V Block Model.