5 Clinical Trials for Various Conditions
This clinical study has been designed to test whether a new pacing therapy would lead to improvement in heart function, symptoms and quality of life in a specific group of heart failure patients. This group has a unique electrical conduction problem (Right Bundle Branch Block) that did not respond well to the current available pacing therapy.
Heart failure (HF) affects 5 million Americans and is responsible for more health-care expenditure than any other medical diagnosis. Approximately half of all HF patients have electrocardiographic prolongation of the QRS interval and ventricular dyssynchrony, a perturbation of the normal pattern of ventricular contraction that reduces the efficiency of ventricular work. Ventricular dyssynchrony is directly responsible for worsening HF symptomatology in this subset of patients. Resynchronization of ventricular contraction is usually achieved through simultaneous pacing of the left and right ventricles using a biventricular (BiV) pacemaker or implantable cardioverter-defibrillator. Clinical trial evidence supporting the use of BiV pacing in patients with prolonged QRS duration was obtained almost exclusively in patients with a left bundle-branch block (LBBB) electrocardiographic pattern. Recent evidence suggests that resynchronization of ventricular contraction in patients with LBBB can be obtained by univentricular left ventricular pacing with equal or superior clinical benefits compared to BiV pacing. Animal studies suggest that ventricular resynchronization can be obtained in subjects with right bundle-branch block (RBBB) through univentricular right ventricular pacing. No clinical trial evidence exists to support the use of BiV pacing in patients with RBBB. Thousands of patients with symptomatic HF and RBBB currently have univentricular ICDs in place for the prevention of sudden cardiac death. Most of these devices are currently programmed to avoid RV pacing. We aim to determine if ventricular resynchronization delivered through univentricular RV pacing improves symptoms in patients with RBBB and moderate to severe HF who have previously undergone BiV ICD implantation for symptomatic heart failure. We further aim to determine if ventricular resynchronization improves myocardial performance and ventricular geometry as detected by echocardiographic measures and quality of life for patients with HF and RBBB. We hypothesize that RV univentricular pacing delivered with an atrio-ventricular interval that maximizes ventricular synchrony is equivalent to BiV pacing for improvement in cardiac performance, HF symptoms, and positive ventricular remodeling in patients with HF and RBBB.
This study will address whether acute adaptive RV pacing in sinus rhythm patients with severe LV systolic dysfunction and RBBB is superior to no ventricular pacing, and is as effective as echocardiographically optimized biventricular (BIV) pacing based on Medtronic ECG belt and cardiac performance as assessed by the echocardiographic parameters of RV and LV function.
The investigators aim to prospectively evaluate the efficacy and mechanism of benefit of His-bundle pacing enhanced cardiac resynchronization therapy (His-CRT) vs. cardiac resynchronization therapy (BIV-CRT) in patients with heart failure and right bundle branch block (RBBB).
The purpose of the study is to investigate the superiority of chronic left bundle branch area pacing compared to traditional right ventricular (RV) septal pacing in patients with high-grade conduction disease after transcatheter aortic valve replacement (TAVR). In this investigator initiated, multicenter, prospective, double-blinded, crossover study, chronic left bundle branch area pacing will be compared to chronic right ventricular septal pacing using echocardiographic measures of left ventricular systolic function in patients with a high cumulative ventricular pacing burden after TAVR.