302: Familial atrioventricular node reentrant tachycardias

Abstract

Familial Wolff-Parkinson-White (WPW) syndrome and gene (PRKAG2) was reported. Rare case reports suggest that genetic factors may play a role in the formation of accessory atrioventricular pathways (AP) and dual AV nodal pathways. In this last case, nothing is known, probably because atrioventricular node re-entrant tachycardia (AVNRT) is associated with a good prognosis. The purpose of study was to look for familial forms of AVNRT. 792 patients with a preexcitation syndrome, 251 patients with a normal ECG but with atrioventricular re-entrant tachycardia (AVRT) using a concealed AP and 969 patients with AVNRT were referred in our department. Electrophysiological study (EPS) was performed in all subjects. The familial forms in these groups have been sought. Only patients with documented and/or induced supraventricular tachycardia were retained as having tachycardia. Among patients with a preexcitation syndrome, we did not find familial form of preexcitation syndrome. Sister of a young patient who had presented a WPW-related ventricular fibrillation complained of tachycardia, but AVNRT was identified at electrophysiological study (EPS). Two other patients had a family history of unexplained sudden death, but no ECG was recorded before death in these patients. Among patients with AVRT and normal ECG, one familial form was noted (father and daughter) (0.4%). Among patients with AVNRT, 7 families were identified (0.7%): mother and son (n=4), mother and daughter (n=1), brother and sister (n=1), father and daughter (n=1). The frequency of familial AVNRT was significantly higher than in patients with a preexcitation syndrome (p <0.025). The frequency of familial AVNRT was probably underestimated because frequently patients reported a familial history of tachycardia but the nature of the tachycardia could not be proven. A genetic origin of some AVNRT exists in some families. Its frequency is approximately 0.7% in our population. Although patients with AVNRT are not at risk of life-threatening arrhythmia, the history of tachycardia in family may lead to look for the same tachycardia. The frequency is higher than in preexcitation syndrome.