Prolonged monitoring for detection of symptomatic arrhythmias after slow pathway ablation in AV-nodal tachycardia.

To study the incidence of symptoms and recurrences of AV-nodal re-entrant tachycardia (AVNT) after treatment with radio-frequency ablation of the slow pathway, event recording with transtelephonic transmission was performed for at least 3 weeks in 19 patients out of a series of 25. Follow-up with an implanted antitachycardia device was possible in two other patients, making the total number under continued surveillance 21/25. The period of monitoring was prolonged as complaints remained or became present after 1 month in eight patients. During a mean follow-up of 10 months, late recurrence of AVNT was observed in this way in 4/25 patients; they were submitted to a second procedure. Symptoms were present in many others and were explained by the recordings. Sinus tachycardia was recorded in three patients, intermittent AV-block of the first degree in another, and frequent atrial or ventricular premature beats in six patients. These minor arrhythmias tended to decrease over time. A coexistent atrial tachycardia was redetected in two patients. Thus, event recording is useful to distinguish recurrence of AVNT, sinus tachycardia, other types of supraventricular tachycardia, and atrial or ventricular premature beats, which all may be a reason of complaints during the first weeks after ablation. It provided a feeling of safety for symptomatic patients who often suffered from anxiety before the ablation.