Recurrences of symptoms after AV node re-entrant tachycardia ablation: A clinical arrhythmia risk score to assess putative underlying cause

- Recurrence of symptoms after ablation of atrioventricular nodal re-entrant tachycardia (AVNRT) is relatively frequent (16%).
- True AVNRT recurrence accounts for only 1/3 of these recurrences.
- The origin of symptom recurrences in old patients of male gender was generally due to atrial arrhythmias.
- In contrast, the youngest patients, mainly females, usually had no organic tachycardia but a sinus tachycardia.
- A simple clinical score based on age and history of atrial fibrillation enables efficient risk stratification for symptom recurrence attributable to atrial arrhythmias and inappropriate sinus tachycardia.

Purpose of the researchTo identify clinical factors associated with the probability for each arrhythmic mechanism causing recurring symptoms after atrioventricular nodal re-entrant tachycardia (AVNRT) ablation. Slow pathway radiofrequency ablation is used to treat AVNRT. After ablation, recurrence of symptoms due to AVNRT or other arrhythmias can occur.ResultsWe studied 835 patients successfully treated with AVNRT ablation. Variables associated with each specific arrhythmia underlying symptom recurrence were studied by logistic regression.During a mean follow-up of 2.2 ± 2 years, 136 (16%) patients had a recurrence of symptoms. Following invasive and non-invasive studies, symptoms were mostly attributed to sinus tachycardia, recurrence of AVNRT and atrial arrhythmias (respectively 4.7%, 5.2% and 6.1%). Older age and history of atrial fibrillation were associated with a markedly increased risk of symptom recurrence due to atrial arrhythmias (OR = 15.58, 7.09-35.22, p < 0.001) whereas younger age was associated with a higher risk of sinus tachycardia. A simple 3-item clinical score based on age categories and atrial fibrillation history efficiently predicted atrial arrhythmia (C-Index = 0.82, 0.75-0.89) and sinus tachycardia (C-Index = 0.83, 0.75-0.90). 8.3% of patients with scores = 0 had atrial arrhythmias whereas 100% of patients with scores ≥ 4 had atrial arrhythmias.ConclusionsWhile recurrence of symptoms after successful AVNRT ablation is relatively frequent (16%), true AVNRT recurrence accounts for only 1/3 of these recurrences. A simple clinical score based on age and history of atrial fibrillation enables efficient risk stratification for symptom recurrence attributable to atrial arrhythmias and inappropriate sinus tachycardia.