[Cardiac resynchronization therapy]

Severe cardiac insufficiency with a clearly diminished contraction of the left ventricle is often accompanied by a pronounced left bundle branch block in the EKG. The early and late activated sides of the ventricular walls contract asynchronously, further decreasing the cardiac output. Resynchronization can be achieved through a biventricular pacemaker, which simultaneously stimulates the early and late sides of the ventricular walls. In addition to the electrode usually placed in the tip of the right ventricle, a second electrode is placed on the lateral wall of the left ventricle. This normally leads to an immediate small increase in the blood pressure and to an increased functional capacity. For patients with asynchrony of the left ventricle, an improvement of the cardiac insufficiency by approximately a half of an NYHA class and a decrease in the yearly mortality by 4% has been documented.