Biventricular pacing for heart failure

Left bundle branch block in structurally normal hearts results in loss of synchrony of ventricular contraction and impairs both regional and global left ventricular systolic function.1 In hearts with good overall left ventricular systolic function this has very little clinical effect. But in patients with ischaemic or idiopathic dilated cardiomyopathy it further impairs already poor systolic function and may have a major clinical impact. The prevalence of conduction delay in patients with heart failure is as high as 30%,2 and this has led to the development of biventricular pacing in an attempt to restore synchronous ventricular contraction and so improve left ventricular function. Biventricular pacing involves the transvenous placement of a third pacing lead via the right atrium and coronary sinus into a left ventricular cardiac vein; this is in addition to the standard pacing leads in the right atrium and right ventricle3 and permits simultaneous stimulation of the right and left ventricles. What is the evidence that this works? Several studies have indicated that biventricular …