Cardiac contractility modulation device-new hope for refractory heart failure patients.

ABSTRACT

A large number of patients with advanced heart failure (HF) are refractory to optimal standard medical therapy. This has given rise to development and testing of a host of new device based therapies. One recent and potentially broadly applicable treatment under investigation is cardiac contractility modulation (CCM) electrical signals. The CCM signals are relatively high-voltage electrical impulses applied to the myocardium during the absolute refractory period. These signals do not initiate a new contraction or modify activation sequence as is the case with other therapies such as cardiac resynchronization therapy. Rather, CCM signals are intended to enhance systolic function of the failing myocardium. A device similar to a pacemaker is typically implanted in the right pectoral region. Three standard pacemaker leads are placed intravenously. One right arterial lead is used to sense atrial activity, and two right ventricular leads are used to sense ventricular activity and deliver the CCM pulse trains. The electrodes of the ventricular leads are placed on the right ventricular septum at least 2cm apart. In contrast to a Pacemaker and defibrillator the system is designed to modulate the strength of contraction of the heart muscle rather than the rhythm. Application of CCM signals to the failing heart is associated with improved gene expression which ultimately causes LV global, cellular and biochemical remodeling as a result improved LV systolic function.