Chronic heart failure (CHF) is a very frequent condition. Its frequency increases with prolongation of median life expectancy and due to improvements in medical care. However, medical treatment does not allow adequate control of symptoms in many cases. Therefore, various nonpharmacological approaches are being developed. The so-called biventricular pacing is one of them. Its main goal is to restore impaired mechanical cardiac synchrony that is present in patients with prolonged QRS duration due to inter- or intraventricular conduction abnormality. At present, biventricular pacing can be achieved through positioning of a special pacing lead into a branch of the coronary sinus on the surface of the left ventricle and implanting the other lead into the right ventricular cavity, and the third lead into right atrial appendage. Clinical trials and experience from many centres have documented improvements in clinical status in the vast majority of patients. An improvement in functional classification (NYHA) by at least one class, prolongation of the six minute walk distance by 20 - 40 %, increase the maximal oxygen uptake by 10 - 40 % a beneficial effect on quality of life can be expected. Preliminary results of the COMPANION trial have suggested that cardiac resynchronization therapy is associated with prognostic effect, especially in conjunction with implantable cardioverter-defibrillator.

        Key words: Chronic heart failure - Cardiac resynchronization therapy - Biventricular pacing - Coronary sinus - Left bundle branch block