Aims: The objective of our study was to evaluate the clinical outcome of patients with operated congenital heart disease (CHD), post-operative sinus node dysfunction and atrial tachyarrhythmias (AT) who had a new generation of DDDRP pacemakers (Model AT501, Medtronic Inc., MN, USA) able to deliver preventive atrial pacing and antitachycardia pacing (ATP) therapies.
Methods and results: Fifteen CHD patients (mean age 17+/-9 years, eight after Mustard operation, five after extracardiac Fontan operation and two after atrial septum repair) received a dual-chamber pacemaker with transvenous (eight patients) or epicardial leads (seven patients). In the year before implantation, all patients had symptomatic AT (palpitations), eight patients required hospitalization and five required electrical cardioversion. Pacing prevention algorithms were enabled in all patients, and ATP therapies in six patients. During a mean follow-up of 30 months (range 24-44), three patients (two Fontan, one Mustard) died of CHF, whereas AT required hospitalization in three patients (two Fontan, one atrial septum repair). Only seven patients had symptomatic AT. One hundred and twenty-five AT episodes were treated by ATP in three patients, with an overall termination efficacy of 43.2%. In one patient, atrial lead noise induced inappropriate AT detection that resulted in ATP delivery. Several AT episodes were not treated owing to their very short duration, atrial undersensing, or 1:1 atrioventricular conduction.
Conclusions: Our experience with antitachycardia pacemakers in CHD patients with post-operative sick sinus syndrome after biventricular correction or palliation shows that these devices are safe and that atrial pacing may play a role in AT prevention and treatment.