Anti- and pro-arrhythmic effects of cardiac resynchronization therapy: point of view.

Cardiac resynchronization therapy (CRT) in patients with heart failure and bundle branch block (BBB) improves regional muscle mechanics and mechanical pump function of the heart. In addition, modulation of wall motion timing and contraction can exert an antiarrhythmic effect, reducing the potential of sudden cardiac death. This effect of CRT could also be attributed to the improvement in excitation-contraction coupling, mechanical synchronization, and improved myocardial perfusion.