Clinical study of double-chamber stimulation. Apropos of 50 cases followed-up for 1 to 5 years

The authors report their experience of dual chamber pacing in 29 men and 21 women of mean age 71 +/- 4 years. 35 had sinus node dysfunction associated with node-His bundle conduction disorders; 31 presented with neurological symptoms and 4 with heart failure (due to pacemaker syndrome in 1 case). Sinus node dysfunction was diagnosed by surface ECG in 25 cases and after electrophysiological studied in only 10 cases. Fifteen patients had atrioventricular block without sinus node dysfunction: 2 of them were young subjects, 1 had pacemaker syndrome and 12 were actual or potential heart failure patients for whom preservation of the atrial systole was justified. Nine patients presented with neurological symptoms. 43 (86%) had cardiac or arterial disease associated with cardiac rhythm and conduction disorders. The percutaneous single subclavian vein approach was used in 36 cases (78%). 41 active and 9 passive fixation electrodes were utilized. The mean follow-up period was 25 months (12 to 70 months), with a cumulative figure of 1,253 months/patients. Two late re-operations for displacement of the atrial electrode were performed. Dual chamber pacing was abandoned, 14 months on average after implantation, in 9 patients (18%), on account of arrhythmias in 4 of them. Three cases of tachycardia from "electronic re-entry" and 6 cases of supraventricular arrhythmia transferred to the ventricle by the pacemaker were observed. Sixteen patients (32%) died 12 +/- 4 months on average after surgery: 12 (33%) had sinus node dysfunction and 4 (26%) had AV block. Death was caused by a cardiovascular disease in 12 cases.(ABSTRACT TRUNCATED AT 250 WORDS)