Atrial septal pacing in the prevention of paroxysmal atrial fibrillation refractory to antiarrhythmic drugs

BACKGROUND: Early reports have shown that pacing the atria at a site or sites other than the right atrial appendage may prevent atrial fibrillation. Our centre has shown that pacing the atrial septum reduces the duration of atrial activation which is an important determinant of predisposition to paroxysmal atrial fibrillation. Ablation of the atrioventricular (AV) node together with implantation of a pacemaker can control symptoms due to paroxysmal atrial fibrillation in patients in whom antiarrhythmic drugs have failed. The aim of this study was to investigate the effect of atrial septal pacing on patients who were candidates for AV node ablation. METHODS: Atrial septal pacemakers were implanted in 28 patients with symptomatic, paroxysmal atrial fibrillation that had been unresponsive to two or more antiarrhythmic drugs. Pacing was not indicated for any reason other than the anticipated need to proceed to AV node ablation. Change in symptoms was assessed by quality of life questionnaires and recurrence of atrial fibrillation was measured objectively by pacemaker interrogation and ambulatory electrocardiographic monitoring. RESULTS: Atrial septal pacing in combination with an antiarrhythmic agent resulted in a substantial subjective improvement in 19 patients (68%). Objective data confirmed similar findings; atrial fibrillation was completely or markedly reduced in 17 patients (60%). Six patients experienced a modest improvement in symptoms; in only four patients was it necessary to proceed to AV node ablation. CONCLUSIONS: Atrial septal pacing together with continuance of previously ineffective antiarrhythmic therapy may prevent or markedly reduce the frequency of paroxysmal atrial fibrillation and obviate the need to ablate the AV node.