PREDICTORS OF ATRIAL RHYTHM AFTER ATRIOVENTRICULAR NODE ABLATION FOR THE TREATMENT OF PAROXYSMAL ATRIAL ARRHYTHMIAS

Objective-To assess the natural history of the atrial rhythm of patien ts with paroxysmal atrial arrhythmias undergoing atrioventricular node ablation and permanent pacemaker implantation. Design and setting-A r etrospective cohort study of consecutive patients identified front the pacemaker database and electrophysiology records of a tertiary referr al hospital. Patients-62 consecutive patients with paroxysmal atrial a rrhythmias undergoing atrioventricular node ablation and permanent pac emaker implantation between 1988 and July 1996. Main outcome measures- (l) Atrial rhythm on final follow up EGG, classified as either ordered (sinus rhythm or atrial pacing) or disordered (atrial fibrillation, a xial flutter or atrial tachycardia). (2) Chronic atrial fibrillation, defined as a disordered rhythm on two consecutive ECGs (or throughout a 24 hour Holter recording) with no ordered rhythm subsequently docume nted. Results-Survival analysis showed that 75% of patients progressed to chronic atrial fibrillation by 2584 days (86 months). On multiple logistic regression analysis a history of electrical cardioversion, in creasing patient age, and WI pacing were associated with the developme nt of chronic atrial fibrillation. A history of electrical cardioversi on and increasing patient age were associated with a disordered atrial rhythm on the final follow up EGG. Conclusion-Patients with paroxysma l atrial arrhythmias are at high risk of developing chronic atrial fib rillation, A history of direct current cardioversion, increasing patie nt age at the time of ablation, and WI pacing are predictive of the de velopment of chronic atrial fibrillation in this patient group.