Response to Cardiac Resynchronization Therapy of Previously Right Ventricular Paced Heart Failure Patients
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.
Pacing Induced Dyssynchrony
|Study Design:||Time Perspective: Retrospective|
|Official Title:||Response to Cardiac Resynchronization Therapy of Previously Right Ventricular Paced Heart Failure Patients|
- Death from any cause [ Time Frame: Average of 4 years ] [ Designated as safety issue: Yes ]Retrospectively measure the time in days from device implant to death, if applicable.
- Cardiovascular Hospitalization [ Time Frame: Average of 4 years ] [ Designated as safety issue: Yes ]Retrospectively measure the time in days from device implant to hospitalization, if applicable.
- Change in ejection fraction [ Time Frame: Approximately one year ] [ Designated as safety issue: No ]A measure of cardiac performance.
|Study Start Date:||October 2011|
|Estimated Study Completion Date:||January 2013|
|Estimated Primary Completion Date:||November 2012 (Final data collection date for primary outcome measure)|
Previously RV Paced
Patients who were RV paced prior to receiving a cardiac resynchronization therapy device.
Non-Previously RV Paced
Patients who received a CRT device without being previously RV paced.
The RV apex has historically been used as the site for ventricular pacing in cases of sinus node dysfunction or atrioventricular block because of its relatively accessible location for lead implantation. Initial studies showed RV pacing improved symptoms, exercise capacity, quality of life, and survival in these patients.11-13 However, more recent studies have illustrated that chronic RV pacing may actually impair LV systolic function and increase the risks of heart failure, hospitalization, and death in some patients.
The primary hypothesis is that patients upgraded to CRT from a RV pacemaker respond better than those receiving CRT as a first time device. To test this hypothesis the investigators will compare changes in cardiac size and function, and hospitalization and survival rates between the two patient groups.
The second hypothesis will investigate whether changes in septal dyssynchrony are correlated with changes in ejection fraction in previously RV paced patients. The investigators believe that the patients with the most improvement in septal dyssynchrony due to RV pacing will see the greatest improvement in LV function following upgrade to CRT. A significant correlation between change in IM-S and change in EF will support the hypothesis.
|United States, Minnesota|
|United Heart & Vascular Clinic|
|St. Paul, Minnesota, United States, 55102|
|Principal Investigator:||Alan J Bank, MD||United Heart & Vascular Clinic|