AIMS The aim of the study was to assess efficacy and safety of a novel method of multisite atrial pacing, incorporating Bachmann's bundle (BB) and coronary sinus (CS) ostium pacing, which was implemented for the first time in atrial fibrillation (AF) patients with intra-atrial conduction delay. METHODS AND RESULTS This follow-up study included 97 patients with drug refractory symptomatic AF, sinus node dysfunction, sinus P-wave > or = 120 ms, and normal atrioventricular conduction. Pacing efficacy was assessed on the basis of two main endpoints: successful rhythm control and the absence of documented or symptomatic AF. During the mean 2.3 +/- 0.7 years of follow-up, the survival rate was 99%, pacing maintenance rate 97%, and the need for re-operation 5%. Rhythm control efficacy was 90%, and 14 patients had no evidence of recurrent AF. After implantation, the mean number of anti-arrhythmic drugs used (P < 0.0001), the need for cardioversion (P < 0.01), and the incidence (P < 0.0001) and duration (P < 0.001) of AF-related hospitalizations decreased. P-wave duration with multisite atrial pacing was shorter than during sinus rhythm, BB, and CS pacing (P < 0.0001). CONCLUSION A novel method of multisite atrial pacing is safe, provides effective long-term rhythm control, and decreases the necessity for adjunctive therapies in patients with refractory AF and intra-atrial conduction delay.