Twenty-five patients with second- to third-degree AV block and normal sinus function (16 males, mean age 60 +/- 18; range 15-78 years) underwent implantation of VVD pacemakers (THERA VDD, Medtronic, Inc.) with a single pass (SP) lead.
Results: During implantation the mean amplitude of the atrial (A) signal was 3.9 +/- 1.4 mV (range 2.0-7.8 mV). Stable, acceptable A-signals during implantation were usually observed in the mid- or lower part of the right atrium. The lead tip electrical parameters were not compromised in any patient in order to obtain an acceptable A-signal. To verify VDD device function, patients underwent pacing system analysis on the second day and again 1, 3, and 6 months after implantation. Acute and chronic electrical measurements in the ventricle were similar to those with regular steroid leads. During follow-up tests, stable atrial sensing (A > or = 0.7 mV) was found in all but one patient (in whom A was 0.25-0.5 mV and an intermittent loss of atrial sensing occurred). There was no difference between serial measurements of A-signal amplitudes on the second day or 1, 3, and 6 months after implantation: 1.9 +/- 1.3 mV, 1.5 +/- 0.6 mV, 1.3 +/- 0.8 mV, and 1.5 +/- 1.1 mV, respectively. The mean implantation time was 54.0 +/- 17 minutes and the mean fluoroscopy time was 3.2 +/- 1.3 minutes.
Conclusions: SP lead VDD pacing is reliable and easy to manage with dependable atrial sensing and ventricular pacing.(ABSTRACT TRUNCATED AT 250 WORDS)