[Cardiac contractility modulation: a new option for treating systolic heart failure]

Cardiac contractility modulation (CCM) is a recently developed electrical treatment for enhancing ventricular contractility by non-excitatory impulses applied during the absolute refractory period in advanced systolic heart failure, regardless of the presence of dyssynchrony and QRS prolongation. Implantation of a CCM device is comparable to pacemaker implantation. Three electrodes are placed in the heart via the subclavian vein. One electrode in the right atrium is used for sensing, while ventricular stimulation is done by two electrodes in the right ventricle. The FIX-CHF-4 trial was a randomized, double-blind and cross-over study in 164 patients with systolic heart failure and an ejection fraction 35%, in order to evaluate the effect of CCM treatment on exercise capacity and quality of life. After three months the patients' six-minute walk distance increased, while ejection fraction remained unchanged. Moreover, quality of life improved. CCM stimulation was found to be a safe method. In patients with heart failure and left ventricular systolic dysfunction exercise tolerance and quality of life may be improved by CCM. Further studies to determine morbidity and mortality during long-term CCM stimulation are indicated.