Efficiency Study of Triple-Site Cardiac Resynchronization in Patients With Heart Failure

Inclusion Criteria: * Age 18 or more, * Congestive heart failure (HF) in NYHA class III-IV within last 90 days despite optimal medical treatment, * Left ventricular ejection fraction (EF) \<=35% measured with echocardiography, * Sinus rhythm \>90% of the time in 24-h Holter monitoring 1-3 days prior to randomization, * Inter- or intraventricular mechanical dyssynchrony ≥40ms measured with pulse Doppler and tissue Doppler echocardiography, * Optimal pharmacotherapy during the last 90 days, * Signed informed, written consent. Exclusion Criteria: * Pregnancy or breastfeeding, * Unstable HF requiring hospitalization with intravenous inotropic drugs within last 90 days, * Myocardial infarction, percutaneous/surgical revascularization or any cardiosurgical procedure within 90 days prior to randomization, * Stroke within last 90 days, * History of chronic or persistent atrial fibrillation, flutter, tachycardia, * Acute myocarditis, * Implanted previously pacemaker, ICD or CRT-device, * Participation in a concurrent trial that could confuse the results of this study, * Mechanical right heart valve, * Prior heart transplant, * Valvular disease that is indication for valve surgery, * Coronary heart disease if percutaneous or surgical revascularization is indicated and possible, * Any state, apart from HF, that limits the estimated survival time to \<1 year, * Unwillingness or inability to understand the nature of the study, to participate or to give written informed consent.