Single-lead VDD pacing: long-term experience with four different systems.
BACKGROUND: Previous multicenter studies have shown that single-lead VDD pacing systems provide satisfactory atrial-triggered ventricular pacing at middle term for treatment of atrioventricular block without sinus dysfunction. However, we lack data on long-term results obtained with 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 symptomatic hypertrophic cardiomyopathy (n = 3) without sinus dysfunction were paced with four different VDD pacing systems able to sense the atrium and to pace the ventricle. Atrioventricular synchronization was assessed during follow-up by ECG and Holter monitoring. RESULTS: Mean value of the atrial electrogram during implantation was 2.01 +/- 0.94 mV without any differences among the four systems. With a mean follow-up of 24 +/- 11 months, 95% of patients remain paced in VDD mode, whereas 5% have been reprogrammed in VVI or VVIR mode for permanent atrial fibrillation 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. CONCLUSIONS: These different single-lead VDD systems can provide satisfactory long-term atrioventricular synchronization; results are comparable to those obtained with conventional DDD pacing systems with two leads.