[Safety and effectiveness of single-lead VDD pacing].
OBJECTIVE
Single-lead VDD pacing provides the physiological benefits of atrioventricular synchrony with the convenience of a single-lead system. However, concern remains about the method's safety and effectiveness.


METHODS
In total, 700 patients with single-lead VDD pacemakers were evaluated retrospectively. The following parameters were recorded: age, sex, etiology, the symptoms and electrocardiographic diagnosis that justified pacemaker implantation, the venous access route used for implantation, atrial sensing at implantation, atrial undersensing at follow-up, the occurrence of supraventricular tachyarrhythmias, and final pacing mode.


RESULTS
Third-degree atrioventricular block was the main indication for pacemaker implantation (66.4%). The most commonly used venous access route was via the right cephalic vein (49.1%). At implantation, the mean atrial signal was 1.8 (4 1.15) mV. During follow-up, significant atrial undersensing occurred in 7.7% of patients; in 1.9%, it could not be corrected by device reprogramming. Uncontrollable supraventricular arrhythmias were observed in 6.4% of patients. Symptomatic sinus node disease was rare. By the end of follow-up, 91.4% of patients were still on VDD pacing, while, in 8.3%, the pacemaker had to be reprogrammed to the VVI mode. Only 0.3% required atrial lead implantation for DDD pacing. Left-side venous access during implantation was a independent predictora of atrial undersensing at follow-up. Low values of atrial detection at implant did not reach statistical signification although it showed a remarkable trend.


CONCLUSIONS
Single-lead VDD pacing seems to be safe and effective when appropriately indicated. Our findings are consistent with those of previously published studies.
Chabbar Boudet
Maruan C
MC
Unidad de Marcapasos, Servicio de Cardiología. Hospital Universitario Miguel Servet, Zaragoza, España. maruancarlos@yahoo.com
Lukic
Antonella
A
Galache Osuna
José G
JG
De Juan Montiel
Jesús
J
Cay Diarte
Eduardo
E
Diarte de Miguel
José A
JA
Placer Peralta
Luis J
LJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods*; D004567:Electrodes, Implanted / Q000009:adverse effects; D005260:Female; D006327:Heart Block / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D012449:Safety; D016896:Treatment Outcome