Case presentation
The patient was a 22-year-old woman (height: 165 cm; weight: 86.5 kg; BMI: 31.8 kg/m2). She was scheduled to undergo endometrial ablation for endometrial hyperplasia. Regarding her medical history, she experienced a cardiopulmonary arrest owing to ventricular fibrillation at the age of 15, at which time she was diagnosed as having coronary spasm via a coronary angiogram and acetylcholine stress test. She underwent ICD implantation, together with the initiation of treatment with a Ca2+ blocker and coronary dilators. The ICD was activated 4 times in 6 years, and the patient resumed a self-paced heartbeat. After a careful interview regarding the circumstances of the onset of her symptoms, we strongly suspected menstrual-associated coronary spasm, as her symptoms occurred from just before menstruation to the middle of menstruation. Estrogen/progesterone replacement therapy was started, and her ICD activation and angina attacks ceased. When she was 22 years old, we decided to perform an endometrial ablation with tissue biopsy for endometrial hyperplasia that was thought to be caused by the estrogen/progesterone medication. Her family history included coronary angina pectoris in the father. Her oral medications were diltiazem (120 mg/day), nifedipine (40 mg/day), nicorandil (25 mg/day), and isosorbide mononitrate (40 mg/day), and an isosorbide mononitrate patch (80 mg/day). She had no history of smoking. Her first menstrual period was at 11 years old, and her menstrual cycle was 30 days and regular. Her last menstrual period was 14 days before the scheduled surgery. Blood test findings were normal. Chest X-ray displayed no cardiac enlargement or abnormal shadows, except for the presence of an ICD device. Preoperative estradiol levels were 63.1 pg/mL in the follicular phase, and 42.9 pg/mL in the ovulatory phase, which were within the normal ranges for these phases in nonpregnant women. Her ECG results were normal, with a pulse of 55 beats/min, sinus rhythm, and a corrected QTc of 403 ms. Transthoracic echocardiography displayed an ejection fraction of 65%, no abnormal wall motion, no systolic or diastolic dysfunction, and no apparent valvular disease. There were load-induced right ventricular abnormalities, and she had a NYHA classification of grade I. Anesthesia was induced with remifentanil (0.3 µg/kg/min) and propofol TCI (4.0 µg/mL), and muscle relaxation was achieved with rocuronium bromide (50 mg). After endotracheal intubation using a McGrath MAC® video laryngoscope (Medtronic Co., Minneapolis, MN, USA), anesthesia was maintained with propofol TCI (4.0 µg/mL), continuous infusion of remifentanil (0.1–0.2 µg/kg/min), and rocuronium bromide 50mg, and sedation levels were monitored using the patient state index measured with a Sedline® monitor (Masimo Co., Irvine, CA, USA), and maintained at scores between 30 and 50. In addition, an observation arterial pressure line was taken. Intraoperative and postoperative nicorandil (1 µg/kg/min) and diltiazem (1 µg/kg/min) were continuously administered intravenously. The patient remained unchanged and her blood pressure did not decrease, and no antihypertensive or antiarrhythmic medications were administered during the surgery. Surgery time was 13 minutes, and anesthesia time was 49 minutes. Bleeding was minimal. The surgery was completed without any complications, and the patient was extubated and returned to the ICU after surgery. The patient was discharged on the day after the surgery.