Cardiac pacing has been proposed for patients with advanced heart failure refractory to optimal drug treatment and having conduction disorders to resynchronize mechanical activity of the heart. Activation asynchronism as caused by bundle branch block results in alteration of systolic function and arrhythmias. A too short or too long atrio-ventricular delay can also affect diastolic ventricular filling. Early clinical studies showed a benefit of very long atrioventricular delays shortening, not confirmed by further studies. Direct stimulation of the left ventricle was beneficial in acute hemodynamic studies. Three controlled clinical studies now completed, PATH-CHF, MYSTIC and MIRACLE have showed a functional benefit. Other studies (COMPANION, CARE-HF) are currently in process to evaluate the effect on survival and the interest to associate an automatic defibrillator. Technical aspects are also under investigation: optimal lead placement in the coronary venous system, types of leads, special pacing devices. This paper reports the experience of the first 50 patients treated with multisite pacing in Aix-en-Provence general hospital, 33 men and 17 women, 71 years of mean age, on NYHA class III or IV, and showing QRS width above 120 ms. During the follow-up (mean duration 16 months) 15 deaths (30%) happened. The benefit on NYHA class was 1.34; rehospitalization rate was low. Coronary sinus access was successful in 100% of cases. Sixteen per cent had a reintervention for lead displacement or threshold elevation. Left atrioventricular crosstalk, observed in six patients, supports the use of devices with three independent channels. Echocardiography is of interest for responders identification, optimal device programming and follow-up.