Comparison of Epicardial Versus Conventional Lead Placement in Cardiac Resynchronization Therapy

Inclusion Criteria: * Symptomatic NYHA class III or IV heart failure from idiopathic or ischemic heart failure * QRS interval greater than or equal to 130 msec * Left ventricular end diastolic diameter greater than or equal to 55 mm * left ventricular ejection fraction less than or equal to 35 * Willingness to participate Exclusion Criteria: * Acute renal failure; active GI bleeding; unexplained fever which may be due to an infection * untreated active infection * acute stroke * severe uncontrolled systemic hypertension * severe systemic electrolyte imbalance * severe concomitant illness that drastically shortens life expectancy * severe coagulopathy * history of severe COPD and inability to tolerate single lung ventilation * History of prior left sided thoracotomy * history of recent intravenous drug use * concomitant psychiatric diagnosis that impairs patient's ability to comply with study protocol * participation in another investigational protocol