14 Clinical Trials for Various Conditions
The study is a randomized, single-blind crossover prospective study in which investigators will determine the clinical outcomes of cardiac resynchronization therapy (CRT) pacing modalities in patients with left ventricular assist devices (LVAD). Only patients are blinded. This is a small-scale study from which future larger scale randomized controls can be performed. The primary endpoint will be the effect of BiV and RV pacing setting on the 6-minute walk test.
In pulmonary arterial hypertension (PAH), progressive pulmonary vascular remodeling leads to supraphysiologic right ventricular (RV) afterload. Pharmacologic trials have shown that aggressive upfront treatment reversing pulmonary vascular remodeling successfully increases RV function and improves survival. To date, however, there are no proven treatments that target RV contractile function. Echocardiographic studies of RV dysfunction in the setting of pressure overload have demonstrated intra and interventricular dyssynchrony even in the absence of overt right bundle branch block (RBBB). Electrophysiologic studies of patients with chronic thromboembolic disease (CTEPH) at the time of pulmonary endarterectomy have shown prolongation of action potential and slowed conduction in the right ventricle which has correlated with echocardiographic measures of dyssynchrony. Cardiac MRI measures of RV strain in patients with PAH demonstrated simultaneous initiation of RV and left ventricular (LV) contraction, but delayed peak RV strain suggesting that interventricular dyssynchrony is a mechanical rather than electrical phenomenon. Prior studies of RV dysfunction in an animal model, computer model, congenital heart disease, and CTEPH have suggested acute hemodynamic benefits of RV pacing. However, RV pacing has not been studied in patients with PAH. Furthermore, it remains unclear if pacing particular regions of the RV can achieve a hemodynamic benefit and what cost this hemodynamic improvement may incur with regards to myocardial energetics and wall stress. Therefore, the investigators propose to examine RV electrical activation in PAH, map the area of latest activation, and then evaluate the hemodynamic and energetic effects of RV pacing in these patients.
The purpose of this study is to evaluate the efficacy of the VIP™ feature (available in dual chamber Victory® devices) to reduce unnecessary RV pacing, and to determine if patients with implanted SJM pacemakers will benefit by using VIP™ rather than only a programmed AV/PV delay.
Heart failure is a progressive disease that decreases the pumping action of the heart. This may cause a backup of fluid in the heart and may result in heart beat changes. When there are changes in the heartbeat, sometimes a pacemaker is used to control the rate and rhythm of the heartbeat. In this trial, the researchers will test if pacing both the left and right lower half of the heart (ventricles) will: * decrease the number of hospital and clinic visits due to heart failure symptoms * extend life * delay heart failure symptoms as compared to those who are paced in only one ventricle (the right ventricle)
The purpose of the Optimize RV Follow-Up study is to determine the long-term effect of selective site pacing. Selective site pacing refers to which area of the right ventricle the lead is placed. The goal of selective site pacing is to improve how the heart contracts when paced.
The effect of cardiac pacing leads on tricuspid regurgitation is unclear. This study will determine whether using a smaller diameter leads and an alternate position in the ventricle, the proximal septum, will reduce tricuspid regurgitation than larger leads placed in the apex.
SAVE PACe is a large, prospective, single-blinded, randomized clinical trial with the main objective to study the effect of unnecessary right ventricular apical pacing on the clinical outcome of time to development of persistent AF.
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.
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.
Continuous right ventricular (RV) pacing demonstrates harm in patients with normal left ventricular (LV) function as well as in patients with cardiomyopathy and clinical heart failure. However, little is known about RV pacing in patients with advanced heart failure treated with an implantable left ventricular assist device (LVAD). The univentricular support provided by contemporary continuous flow LVAD's has improved outcomes for many advanced heart failure patients, yet the incidence of RV failure in the early post-operative period following implantation is associated with significantly reduced survival and increased length of stay. Acute LVAD unloading of the left ventricle has adverse effects on RV shape and size that contribute to post-operative RV failure. By promoting RV synchrony, RV overdrive pacing may counteract these adverse mechanical alterations, improving RV systolic function and ultimately LVAD function. The investigators will recruit all patients referred for an implantable, continuous flow LVAD at Duke University Medical Center who have an existing implantable dual-chamber cardioverter-defibrillator. Patients will be prospectively randomized into two cohorts to compare continuous right ventricular pacing vs. native ventricular conduction at equivalent heart rates. Multiple clinical outcomes will be examined over a two week period post-operatively including invasive hemodynamics, vasoactive medication use, end-organ function, RV function by Echocardiography as well as patient symptoms and functional status.
The goal of this prospective single center clinical trial is to evaluate the safety and feasibility of performing simultaneous exercise stress cardiac magnetic resonance (CPET-CMR) and cardiopulmonary exercise testing in patients with pre-existing left bundle branch area pacemakers (LBBAP) programmed to an atrial sensing mode. Measurements of right ventricular, left ventricular function, and exercise capacity will be obtained at various LBBAP programming parameters at rest and during low intensity exercise. The main aims of the study are: * Demonstrate the safety and feasibility of performing CPET-CMR in patients with pre-existing LBBAP programmed to P-synchronous ventricular pacing mode. * Generate preliminary data evaluating differences in RV function, LV function, and exercise capacity during various pacemaker programming settings.
The hypothesis of this study is that temporary biventricular pacing will improve hemodynamic performance in patients with right ventricular dysfunction after open cardiac chamber cardiac surgery.
The present proposal is designed to investigate the response to CRT in patients who were previously paced from the right ventricle (RV). The negative physiologic and structural changes associated with chronic RV pacing are well documented, but patient response following upgrade to CRT after chronic RV pacing has not been well characterized in a large cohort.
This study will compare single coil right ventricular defibrillation leads for implanted cardioverter/defibrillators (ICDs) in the apical and high septal locations. It is hypothesized that RV septal positions are at least as good as apical positions using formally measured defibrillation thresholds(DFTs), and that they may have long term advantages in reducing left ventricular dysfunction.