Influence of age and gender on the mechanism of supraventricular tachycardia.

OBJECTIVES: The objective of this study was to determine the impact of age and gender on the mechanism of paroxysmal supraventricular tachycardia (PSVT).

BACKGROUND: Previous studies have indicated that PSVT mechanism may be influenced by age and gender, but contemporary data are limited.

METHODS: In 1,754 patients undergoing catheter ablation of 1,856 PSVTs between 1991 and 2003, the mechanism was classified as atrioventricular reentrant tachycardia (AVRT), atrioventricular nodal reentrant tachycardia (AVNRT), or atrial tachycardia (AT). Patients with inappropriate sinus tachycardia, atrial flutter, atrial fibrillation, and age <5 years were excluded.

RESULTS: The mean age was 45 +/- 19 years (range 5-96), and the majority were women (62%). Overall, AVNRT was the predominant mechanism (n = 1,042 [56%]), followed by AVRT (n = 500 [27%]) and AT (n = 315 [17%]). There was a strong relationship between age and PSVT mechanism; the proportion of AVRT in both sexes decreased with age, whereas AVNRT and AT increased (PM < .001 by ANOVA). The majority of patients with AVRT were men (273/500 [54.6%]), whereas the majority of patients with AVNRT and AT were women (727/1,042 [70%] and 195/315 [62%], respectively). The distribution of PSVT mechanism was significantly influenced by gender (P < .001). In women, 63% had AVNRT, 20% had AVRT, and 17.0% had AT. In men, 45% had AVNRT, 39% had AVRT, and 17% had AT. AVNRT replaced AVRT as the dominant PSVT mechanism at age 40 in men and at age 10 in women.

CONCLUSIONS: The mechanism of PSVT in patients presenting for ablation is significantly influenced by both age and gender.