Safety, Performance, and Efficacy of Cardiac Contractility Modulation Delivered by the 2-Lead Optimizer Smart System: The FIX-HF-5C2 Study.

Background: Prior studies of cardiac contractility modulation (CCM) employed a 3-lead Optimizer system. A new 2-lead system eliminated the need for an atrial lead. This study tested the safety and effectiveness of this 2-lead system compared with the 3-lead system.

Cardiac contractility modulation by electric currents applied during the refractory period in patients with heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

We assessed the feasibility of cardiac contractility modulation (CCM) by electric currents applied during the refractory period in patients with heart failure (HF). Extracellular electric currents modulating action potential and calcium transients have been shown to potentiate myocardial contractility in vitro and in animal models of chronic HF. CCM signals were biphasic square-wave pulses with adjustable amplitude, duration, and time delay from sensing of local electric activity.