Background. Identifying & optimizing strategies to reduce the burden of heart failure (HF) is vital. Despite advances in pharmacotherapy, patients with HF are at high risk for death & hospitalization. Over 25% of patients with systolic HF have dyssynchronous ventricular contraction that results in paradoxical septal motion, further impairing left ventricular (LV) function & HF progression. Cardiac resynchronization therapy (CRT) synchronizes ventricular mechanical activity, improves cardiac output & reduces HF symptoms. However, ~50% of patients do not clearly respond to CRT. Sub-optimal placement of the LV pacing lead appears to be an important reason for non-response.~Screening. Mechanical synchrony is vitally important in optimizing CRT response. Patients will be pre-screened with echocardiograms (echo) & CRT provided to only those with dyssynchrony. The predicted rate of CRT response in patients pre-screened for dyssynchrony is estimated at 65%.~CRT response. The combined use of a valid & simple measure of functional capacity with a reproducible measure of LV volume is optimal in identifying CRT responders. These outcomes will be assessed using the Specific Activity Scale & radionuclide angiography (RNA), respectively.~Primary hypothesis. Targeted LV lead placement will result in an increased probability of CRT response at 52 weeks vs. usual (lateral wall) lead placement. CRT response will be defined as ≥ 10% relative reduction in LV end systolic volume & ≥ 1 Specific Activity Scale class improvement.
Identifying & optimizing strategies to reduce the burden of heart failure is vital. Despite advances in pharmacotherapy, patients with heart failure are at high risk for death & hospitalization. Cardiac resynchronization therapy (CRT) synchronizes ventricular mechanical activity, improves cardiac output & reduces HF symptoms. However, ~50% of patients do not clearly respond to CRT. Sub-optimal placement of the LV pacing lead appears to be an important reason for non-response.~This study will assess whether targeted LV lead placement will result in an increased probability of CRT response at 52 weeks vs. usual (lateral wall) lead placement.