ATRIAL RHYTHM AFTER ATRIOVENTRICULAR JUNCTIONAL ABLATION

Atrioventricular (AV) junctional ablation followed by pacemaker implan tation is an established treatment for patients with refractory paroxy smal atrial arrhythmias. The stability of the underlying atrial rhythm after AV junctional ablation is unknown, This study evaluates the atr ial rhythm after AV junctional ablation in 49 patients with medically refractory atrial arrhythmias, The group included 25 men end 24 women, of whom 36 had known structural heart disease. Poroxysmal atrial fibr illation was the primary rhythm disturbance in 41 patients, whereas 8 manifested either atrial tachycardias or atrial flutter, All patients had failed therapy with greater than or equal to 1 antiarrhythmic drug , Chronic pacing modes were DDIR or DDDR, with mode switching in 15 pa tients and VVIR in 34 patients. After AV junctional ablation, chronic antiarrhythmic drug therapy was prescribed in only 4 patients (8%). Ro utine electrocardiograms (ECGs; 6.5+/-6.1/patient) during long-term fo llow-up (18.6+/-15.6 months) showed that 7 patients (14%) had on atria l arrhythmia detected on all ECGs, 30 patients (61%) had sinus or atri al-paced rhythms on all recordings, and 12 patients (25%) had both atr ial arrhythmias and sinus rhythm documented. Sinus or an atrial-paced rhythm was present on the last available ECG in 33 of 49 patients (67% ). Pacing mode was not a predictor of continued sinus rhythm. In concl usion, most patients with a history of paroxysmal atrial tachyarrhythm ias will not convert to chronic atrial arrhythmias after AV junctional ablation, even in the absence of antiarrhythmic drug therapy. Use of duel-chamber pacing modes will allow maintenance of at least intermitt ent atrial function in these patients. (C) 1996 by Excerpta Medica, In c.