In patients with drug refractory atrial tachyarrhythmias and previous failed attempts of ablation of the arrhythmia substrate, radiofrequency (RF) modulation or ablation of the atrioventricular (AV) junction is an alternative procedure.
Aim: Of this study was to assess the efficacy and long term results of RF AV junction ablation in conjunction with permanent pacemaker implantation, in the management of patients with drug resistant atrial tachyarrhythmias.
Methods: Between 4/92 and 1/97, 46 patients (30 male, 16 female, 67 +/- 12 years) underwent RF AV junction ablation because of paroxysmal atrial fibrillation (24 patients), chronic atrial fibrillation (13 patients), atrial flutter (5 patients) and atrial tachycardia (4 patients). The underlying heart disease was dilated cardiomyopathy (16), ischemic heart disease (9), hypertensive heart disease (6), hypertrophic cardiomyopathy (3), atrial septal defect (2) and non structural heart disease (10). The duration of symptoms was 6.4 +/- 3.5 years at a maximal heart rate 169 +/- 24 bpm. The hospital admissions in the last 12 months were 8.2 +/- 3 per patient. The failed antiarrhythmic drugs were 3.5 +/- 2.1. The functional NYHA class was 2.7 +/- 0.6. Patients with atrial flutter and atrial tachycardia had previous failed attempts of RF ablation of the arrhythmia substrate. Thirty patients had a compromised left ventricular systolic function with LVEF below 50% (mean 34 +/- 9%). AV junction ablation was achieved in all patients after 4 +/- 2.5 RF applications. Post ablation, the selected pacing mode was DDD-R for the 33 patients with paroxysmal atrial tachyarrhythmias and VVI-R for the 13 pts with chronic atrial fibrillation. The dual chamber pacemakers implanted had the option of automatic mode switch.
Results: During the follow-up period of 28 +/- 13 months (6-47), AV conduction recovered in 1 patient. Antiarrhythmic treatment was necessary in only 7 patients. Post ablation the new functional NYHA class was 1.4 +/- 0.8 (p < 0.001). Post ablation hospital admissions, including ordinary pacemaker follow-up visits, were 4 +/- 1 per patient per year (p < 0.001). Six months after the procedure the LVEF of the study population was increased from 42 +/- 16% to 50 +/- 14% (p = NS). In the 30 patients with heart failure the LVEF was significantly increased to 46 +/- 8% (p < 0.05). Symptomatic relief or significant improvement was observed in all patients as showed by the answers given in a customized questionnaire before and after the procedure.
Conclusions: In patients with drug refractory atrial tachyarrhythmias, RF AV junction ablation and permanent pacemaker implantation is an alternative therapy with excellent long term results in terms of arrhythmia control, ventricular performance and quality of life.