Cardiac symptoms related to paroxysmal atrial fibrillation varied with menstrual cycle in a premenopausal woman

Abstract

Atrial fibrillation, an arrhythmia observed more frequently in men than women, is induced by both sympathetic and parasympathetic autonomic nerve activations. The menstrual cycle in premenopausal women has been reported to modulate the autonomic nervous system: parasympathetic activity is dominant in the follicular phase and sympathetic activity is dominant in the luteal phase. However, the relationship between atrial fibrillation and the menstrual cycle has not yet been reported, because this arrhythmia is very rarely detected in premenopausal women. We experienced a 38 year-old woman with paroxysmal atrial fibrillation. Her menstrual cycle was 30.4 ± 0.5 days and the menstrual period was 3.9 ± 0.2 days for 22 cycles. Although she had taken flecainide 200 mg/day, bepridil 200 mg/day, and propranolol 20 mg/day, she sometimes experienced mild palpitations. QTc intervals measured at her visits to our clinic were 440 ± 3 msec in the follicular phase and 425 ± 2 msec in the luteal phase (P = 0.01). These changes in QTc intervals during the menstrual cycle are compatible with earlier reports. During the 22 menstrual cycles, she felt palpitations on 3.2 ± 0.7 days in the menstrual period, 6.4 ± 0.3 days in the follicular phase, and 4.1 ± 0.4 days in the luteal phase (P = 0.01). Afterward, the medication was changed from daily to periodic administration for one week beginning a couple of days before the expected menstrual time, and she did not feel symptomatic variation in her menstrual cycle. These data suggest that her symptoms related to atrial fibrillation might have been dependent on parasympathetic activity.