Introduction: The aim of this study was to assess the long term results (minimum of 3 years) of radiofrequency catheter ablation in patients with common (slow-fast) atrioventricular nodal reentrant tachycardia.
Patients and methods: Sixty consecutive patients (mean age 56 +/- 16 years, range 14 to 83, 16 men and 44 women) underwent slow pathway (n = 51, Group A) or fast pathway (n = 9, Group B) radiofrequency catheter ablation between January 1992 and March 1994. All patients were followed at 1, 3, 6 and 12 months after ablation with serial examinations and electrocardiograms and the last follow-up was made on April 1997.
Results: During a mean follow-up period of 48 +/- 7 months (range 38 to 63) all evaluated patients remained asymptomatic. Eight recurrences were observed at a mean of 1 +/- 2 months (range, 0.5 to 7) after a successful ablation procedure. A second procedure was effective in eliminating the dual atrioventricular nodal pathway in each of them. In Group A patients, the pre-ablation PR interval, at 12 months after ablation and at last follow-up were 122 +/- 11, 124 +/- 13 and 124 +/- 15 ms, respectively. In Group B patients, the pre-ablation PR interval, at 12 months after ablation and at last follow-up were 130 +/- 24, 200 +/- 12, 200 +/- 24 ms, respectively. No significant atrioventricular conduction disturbances in any patient were observed. One patient developed a new onset left bundle branch block and 4 patients died of noncardiac causes.
Conclusions: In patients with atrioventricular nodal reentrant tachycardia, radiofrequency catheter ablation is a safe and effective therapy, with substantial good results that persist during long term follow-up, with a low recurrence rate and without complications during short and long term outcome.