Cycling of inducibility of paroxysmal supraventricular tachycardia in women and its implications for timing of electrophysiologic procedures

Arrhythmias in women may be affected by phases of the menstrual cycle. This study was designed to determine the prevalence of perimenstrual clustering of spontaneous episodes of paroxysmal supraventricular tachycardia (SVT) i n women. It also tested the hypothesis that women with this temporal patter n of events have an altered probability of induction of paroxysmal SVT duri ng electrophysiologic testing at higher estrogen states (midcycle or with e strogen replacement therapy) than at low estrogen states (perimenstrual or without estrogen replacement). A structured history of the relation of spon taneous paroxysmal SVTs to phases of the menstrual cycle was obtained prosp ectively among 42 women referred during a 3-year period. Patients with cycl ical patterns of spontaneous tachycardias, who had had negative electrophys iologic studies at midcycle or while receiving estrogen replacement therapy , had repeat procedures (1) when premenstrual or at the onset of menses, or (2) after stopping estrogen replacement therapy. Seventeen of 42 consecuti ve female patients (40%) had histories of perimenstrual clustering of arrhy thmias. Six women (4 with normal menstrual cycles, 2 on estrogen replacemen t therapy), who qualified for paired electrophysiologic studies because of a negative initial electrophysiologic study that included provocation with isoproterenol, had inducibility into SVTs during the second study. All 6 ha d dual atrioventricular (AV) nodal pathway physiology, 4 held AV nodal reen trant tachycardia (AVNRT) induced, 1 held both AVNRT and reciprocating AV t achycardias, and 1 had nonsustained AVNRT and an atrial tachycardia induced , Successful ablation procedures were performed in 5 of the 6 patients. Thu s, among women with a history of perimenstrual clustering of paroxysmal SVT and among those receiving estrogen replacement therapy, scheduling of elec tive electrophysiologic procedures at times of low estrogen levels (premens trual or off estrogen replacement therapy) may facilitate the probability o f a successful procedure. (C) 1999 by Excerpta Medica, Inc.