Sahra Sultan KARA
Anatolian Journal of Obstetrics and Gynecology Research - 2026;3(1):56-61
Perimenopause is marked by high-amplitude estradiol variability and loss of progesterone-dependent cycle stabilization, which can modify autonomic tone and myocardial excitability. In women with lifelong vasovagal susceptibility, these endocrine shifts may lower the threshold for bradyarrhythmia or reflex syncope. Severe cardioinhibitory events temporally linked to anovulatory cycles have rarely been reported. A 39-year-old woman with lifelong vasovagal syncope experienced progressive cycle shortening (21-25 days), prolonged bleeding (10 days), and presumed anovulatory cycles, fulfilling Stages of Reproductive Aging Workshop +10 criteria for early menopausal transition. Hormonal evaluation showed suppressed mid-luteal progesterone (<0.5 ng/mL), fluctuating estradiol (24-150 pg/mL), and diminished ovarian reserve (anti-müllerian hormone 0.1 ng/mL). She developed worsening presyncope and cyclical clusters of premature atrial contractions (PACs), which intensified during anovulatory windows and in the 4-5 days preceding menses, and consistently diminished by days 3-5 of menstruation. Holter monitoring revealed sinus bradycardia (45-60 bpm) and low-burden PACs, with an estimated pre-procedural burden of approximately 10%. Tilt-table testing provoked a 40-second asystolic cardioinhibitory response. Given her age and clearly vagal phenotype, cardioneuroablation (CNA) was selected as a physiologic alternative to permanent pacing. During the procedure, prolonged arrest required chest compressions, bag-mask ventilation, and pacing to achieve return of spontaneous circulation. Post-CNA follow-up demonstrated complete resolution of syncope and normalization of resting heart rate (70-80 bpm), while PACs persisted, with burden decreasing to approximately 1% after CNA. Estrogen therapy was avoided because of active smoking and persistently positive antiphospholipid antibodies. This case highlights a potential association between perimenopausal hormonal variability and increased susceptibility to cardioinhibitory reflex syncope in autonomically predisposed women. Recognition of cycle-related symptom patterns may improve clinical awareness and support individualized diagnostic and management approaches.
