Using Echo to Predict Response to CRT

Cardiac resynchronization therapy (CRT) has shown substantial benefits in patients with chronic systolic heart failure (HF) and prolonged QRS durations (used as a marker for ventricular dyssynchrony), yet up to one third of these patients fail to respond to CRT. Interestingly, some patients with drug-refractory HF and normal QRS durations have ventricular dyssynchrony. Researchers hypothesized that echocardiographic measurement of left-ventricular asynchrony might predict response to CRT more reliably.

The subjects were 60 patients who received CRT-capable implanted devices; all had NYHA class III drug-refractory HF, QRS durations >130 msec, and LV ejection fractions (LVEFs) ≤35%. At a pre-implantation echocardiographic evaluation, intravent…