[Long-term clinical assessment of single-lead VDD electric stimulation]

During the last decade single lead VDD pacing has been progressively affirmed as an electrotherapy of choice in patients with advanced atrioventricular block without alterations of the sinus function. It combines the benefits of P-synchronous ventricular pacing with an easy implant procedure when compared to the conventional DDD approach. The aim of this study was to evaluate the validity of such an approach in a large population of patients, all implanted in a single center.

From 1987 up to now, 317 patients, all affected by advanced atrioventricular block and without sinus node dysfunction, were implanted in our center with a single lead VDD pacemaker. During follow-up the persistence of a proper atrioventricular synchronization was assessed and evaluated.

The mean follow-up was 3.9 +/- 2.7 years/patient (range 6-138 months). The 94.6% of implanted systems maintained the normal VDD pacing function. Permanent reprogramming in VVI mode was necessary in 17 patients (5.36%); in 12 (3.78%) because of chronic atrial fibrillation and in 5 (1.63%) for loss of atrial sensing. The percentage of atrial synchronization was optimal (> 98%) and acceptable (> 95%) in 81% and 19% of patients, respectively. Episodes of paroxysmal atrial fibrillation occurred in 3 patients. Neither inhibition by myopotentials nor occurrence of sinus node disease was observed during follow-up. These results are in accordance with those reported by previous studies, performed on a smaller population or on a multicenter basis, and are comparable with the results reported for conventional DDD pacemaker.

Our results confirm the high reliability of the single lead VDD pacing system concerning the long-term persistence of a proper atrioventricular synchronization. Data showed above enforce our opinion that this pacing approach should be considered the treatment of choice in patients with advanced atrioventricular block and preserved sinus node function.