Cardiac resynchronization therapy: helpful now in selected patients with CHF.

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Drs Leclercq and Hare1 and Auricchio and Abraham2 have comprehensively reviewed the state of cardiac resynchronization therapy (CRT). As they emphasize, this novel pacing approach to treat heart failure shortens or optimizes the atrioventricular interval necessary to resynchronize lateral-septal contractions and improves atrioventricular mechanical synchrony by abolishing late diastolic ventriculoatrial gradient and the “presystolic mitral regurgitation” that is often seen with ventricular dyssynchrony. Pacing from the left lateral wall produces early activation of the papillary muscle region and may decrease systolic mitral regurgitation. Relative optimization of ventricular loading conditions as provided by CRT improves myocardial efficiency at no increased oxygen cost and increases systolic function with little effect on diastolic function. In addition to the positive hemodynamic effects mentioned above, CRT reduces sympathetic activity and may induce “reverse remodeling” of the failing left ventricle. With CRT, optimal responders develop smaller left ventricles and contractility is improved in the subsequent days to weeks. The CRT device has more sophisticated software and hardware than standard pacemakers and requires more extensive follow-up visits and, thus, a higher cost. The software allows storage of intracardiac electrograms and monitoring of a patient’s physical activity and heart rates and heart …