The utility of cardiac resynchronization therapy (CRT) for patients with congestive heart failure and electromechanical dyssynchrony is well established. This form of therapy has a salutary effect on both quality of life and survival. Nevertheless, approximately one-third of the patients may not experience clinical benefit. Furthermore, if reverse remodeling, defined as a 415% reduction in end systolic volume, is used as a marker of response, then as many as half of the patients may be considered nonresponders. 1 Several techniques have been used in an attempt to improve the efficacy of CRT. The optimization of AV and VV intervals has been used with marginal benefit. Large studies have suggested that simultaneous vs sequential activation of the ventricles has little effect on the vast majority. 2 Left ventricular (LV) stimulation alone has also been evaluated, and it demonstrated clinical outcomes similar to those demonstrated by biventricular stimulation. 2,3 However, it should be noted that an individual not responding to LV stimulation may benefit from a change to biventricular pacing. 3 Optimizing lead placement by either electrical or hemodynamic parameters has been investigated. Identifying sites of late LV activation and targeting such