SINGLE-LEAD VDD PACING - LONG-TERM EXPERIENCE WITH 4 DIFFERENT SYSTEMS

Background Previous multicenter studies have shown that single-lead VD D pacing systems provide satisfactory atrial-triggered ventricular pac ing at middle term for treatment of atrioventricular block without sin us dysfunction. However, we lock data on long-term results obtained wi th different VDD systems implanted in a large number of patients from a single center. Methods One hundred Fifty patients (76 +/- 11 years) with second-or third-degree atrioventricular block (n = 147) or sympto matic hypertrophic cardiomyopathy (n = 3) without sinus dysfunction we re paced with four different VDD pacing systems able to sense the atri um and to pace the ventricle. Atrioventricular synchronization was ass essed during Follow-up by ECG and Hotter monitoring. Results Mean valu e of the atrial electrogram during implantation was 2.01 +/- 0.94 mV w ithout any differences among the four systems. With a mean follow-vp o f 24 +/- 11 months, 95% of patients remain paced in VDD mode, whereas 5% have been reprogrammed in VVI or VVIR mode for permanent atrial fib rillation or loss of atrial sensing; 96% of patients with sinus atrium have atrioventricular synchronization >90% and 94% of patients have > 95%, without significant difference between the four systems used. Con clusions These different single-lead VDD systems can provide satisfact ory long-term atrioventricular synchronization; results are comparable to those obtained with conventional DDD pacing systems with two leads .