Closed loop stimulation in patients with chronic heart failure and severe chronotropic incompetence: Responders versus non-responders.

Background: Clinical effects of rate-adaptive pacing (RAP) are unpredictable and highly variable among cardiac resynchronization therapy (CRT) patients with chronotropic incompetence. Physiologic sensors such as Closed Loop Stimulation (CLS), measuring intracardiac impedance changes (surrogate for ventricular contractility), may add clinical benefit and help identify predictors of response to RAP. The objective of the present BIOlCREATE study subanalysis was to identify criteria for selection of CRT patients who are likely to respond positively to CLS-based RAP.

Impact of closed loop stimulation on prognostic cardiopulmonary variables in patients with chronic heart failure and severe chronotropic incompetence: a pilot, randomized, crossover study.

Aims: Clinical effects of rate-adaptive pacing in heart failure patients with chronotropic incompetence (CI) undergoing cardiac resynchronization therapy (CRT) remain unclear. Closed loop stimulation (CLS) is a new rate-adaptive sensor in CRT devices. We evaluated the effectiveness of CLS in CRT patients with severe CI, focusing primarily on key prognostic variables assessed by cardiopulmonary exercise (CPX) testing.