[Bi-ventricular synchronous pacing and heart failure]

After initial trials of conventional DDD pacing in dilated cardiomyopathies, the concept of multisite stimulation was introduced in 1994. This new indication of heart failure treatment is based on the correction of myocardial contraction and relaxation asynchronies. European pilot studies including few patients were followed by two multicenters randomized trials (MUSTIC and MIRACLE) that confirmed a significant improvement of functional capacity, quality of life and hemodynamic status. Intraventricular delay and QRS duration shortening seems to be the best predictor of clinical success. Patients with more depressed functional and hemodynamic status seems to benefit most from this therapeutic approach. Two studies (CARE HF and COMPANION) are still conducted which will provide further insight into the effectiveness in terms of prognosis of cardiac resynchronisation therapy in this patient population.