The purpose of this study is to assess the efficiency of permanent biventricular pacing using three ventricular leads in terms of reduction in adverse cardiac events rates, improvement in cardiac capacity and patients' functional status in subjects with congestive heart failure and a physiologic (sinus) rhythm.

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.