View clinical trials related to Sick Sinus Syndrome.
Filter by:Background and Aims Pacemaker implantation for treating bradyarrhythmias typically involves placing a pacing lead through the tricuspid valve (TV) into the right ventricular (RV) apex. It is now known that tricuspid regurgitation (TR) frequently results from this and may lead to increased morbidity or mortality. Recently, left ventricular (LV) pacing through an epicardial vein via the coronary sinus has been widely practiced due to the advent of biventricular pacing. This lead does not cross the TV, potentially reducing the risk of TV dysfunction and may also reduce the risk of LV dysfunction. The investigators hypothesize that LV pacing will prevent the onset of new TR or worsening of pre-existing TR in patients undergoing pacemaker implantation. Methods Patients receiving a pacemaker for sick sinus syndrome (n=20) with an LV ejection fraction <40% will be randomly allocated to receive either conventional RV pacing or LV pacing via the coronary sinus. Serial 2D and 3D transthoracic echocardiography will be performed before implantation, one day post implantation, then at 1 week, 1 month, 6 months and 1 year. The primary endpoints will be new onset TR and the diagnosis of at least moderate TR. Other endpoints include biventricular function, ventricular dyssynchrony, complications of device implantation, mortality and major cardiovascular events.
The purpose of this study is to evaluate the implant procedure and feasibility of a new lead developed to pace and sense the left chambers of the heart.
This is a pilot study into the effects on heart function when pacing the right ventricle (RV). This study aims to enrol a population who are clinically indicated to receive a pacemaker. When normal conduction within the heart fails, the treatment may be to implant a permanent pacemaker. Pacing involves passing a lead via a vein to the heart and using an electrical impulse to stimulate a beat. Increasingly the available evidence suggests that long term RV pacing is associated with complications - left ventricule (LV) dysfunction, heart failure, atrial fibrillation (AF) and death in some patients. What we do not see are a large proportion of all patients who receive pacemakers suffering pacing related adverse effects. If there could be a way of identifying those patients in the group who go on to develop pacing induced cardiomyopathy at the time of initial pacing implant, this would be a very valuable clinical measure. These patients could be identified from the outset and paced with a biventricular device to avoid the pacing induced cardiomyopathy. Whilst much energy has been directed towards the LV as a focus of the clinical markers of disease, little has been published looking at RV haemodynamics. We plan to study a cohort of patients who are clinically indicated to receive a pacemaker and study their RV in detail at the time of implantation. We will use conductance catheters and echocardiography to determine measures of pumping function. We will then follow them up for a period of six month using echocardiography and blood markers of heart dysfunction. In those patients who have a reduction in heart function we will then look for common patterns within their initial measurements.
This is a randomized, prospective clinical trial to determine the effects of two different pacemaker atrioventricular delay (AV delay) settings on heart function in patients with dual chamber pacemakers implanted for symptomatic bradycardia with long PR intervals (delayed conduction between upper and lower chambers of the heart). The study will compare a long, fixed AV delay (standard) with an optimized AV delay for each individual using echocardiography (experimental).
Atrial fibrillation (AF) is prevalent in patients with sick sinus syndrome (SSS) and associated with an increased risk of stroke and death. Within the first two years after pacemaker implantation almost half of the patients are diagnosed with AF. Studies have indicated that an increased amount of stimulation from the pacemaker in the atria is associated with an increased amount of AF. The aim of the present study is to test the hypothesis that a reduction of stimulation from the pacemaker in the atria, and reducing the minimal heart rate, increases the time to AF.
Providing ideal rate response to patients should improve their quality of life and ability to execute activities of daily living. Medtronic pacemakers provide rate response pacing by utilizing dual zone programming to specify an "activities of daily living" (ADL) response rate and an "exertion" response rate. There is much data to support the target heart rate for an exercise response but the data to support the programming of the ADL rate is lacking.
Unnecessary right ventricular pacing has been shown to be detrimental in recipients of implantable pacemaker or defibrillators. The ADVANTAGE study evaluates the efficacy of two pacemaker based algorithms (atrioventricular hysteresis function versus mode switch to atrial pacing) to reduce right ventricular pacing.
The study aims to use cardiac MRI scans and analysis techniques to evaluate differences in cardiac function after 12 months of pacing in patients with pacing leads placed in different positions within the right ventricle (apically or septally).
The objective of the SAMURAI Clinical Study is to collect data to confirm the safety, performance and effectiveness of the ImageReady System for use in the Magnetic Resonance Imaging (MRI) environment when used in accordance with the Conditions of Use included in the Boston Scientific MRI Technical Guide
The objective of this study is to gather data to establish the safety, performance and effectiveness of the INGEVITY pace/ sense leads.