904–47 Permanent Overdrive Atrial Pacing in Chronic Management of Atrial Reentrant Tachycardias in Postoperative Patients with Congenital Heart Disease

Sustained atrial tachycardias occurring after surgery for congenital heart disease, are often difficult to control by antiarrhythmic drugs and by antitachycardia pacing. We implanted a permanent pacing system in 11 pts with drug resistant recurrent atrial reentrant tachycardias. 7 pts were male and 4 female; mean age was 7.4 years (range 1 to 28 yrs); mean time from surgery to the first documented atrial tachycardia was 2.2 years (range 1 month to 9 yrs). All pts had been unsuccessfully treated with two to five antiarrhythmic drugs before pacing. At implantation the atrial pacing rate was programmed to be 20% faster than the mean diurnal spontaneous rate. Individualized programs of pacemaker rate settings were then selected following serial 24 hours Holter monitoring, to obtain a prevailing paced atrial rhythm. Mean follow-up was 3.4 years (range 6 mos to 5 yrs). 3 pts had recurrences of atrial tachycardia during the first six months after the implantation, 8 pts remained arrhythmia free. No patient had late recurrences and only two are still on antiarrhythmic drug therapy. In conclusion : permanent overdrive atrial pacing is a very useful tool in chronic management of postoperative atrial reentrant tachycardias.