Betamethasone-Induced Atrial Fibrillation With Rapid Ventricular Response in Pregnancy: Case Report [05M

Abstract

INTRODUCTION: Atrial fibrillation (AF) is a common cardiac arrhythmia but a rare occurrence in obstetrical patients. METHODS: A 24-year-old G6P2032 without significant medical history presented at 32 3/7 weeks gestation for routine obstetrical care. The fetus was suspected to have a hypoplastic right heart via fetal echocardiography at 24 5/7 weeks of gestation. She reported decreased fetal movement and audible fetal decelerations were noted during her exam. The patient was referred to the hospital and was noted to have category II fetal heart rate tracing (FHR). Considering the possibility of delivery before 37 weeks, she was given 12 mg betamethasone intramuscular injection at 32 3/7 weeks, which was repeated in 24 hours. The FHR improved to category I throughout prolonged monitoring. The following day, the patient returned complaining of severe palpitations, shortness of breath and was noted to have a pulse of 159 BPM while in AF with rapid ventricular response. She was started on an esmolol drip for rate control and failed to spontaneously convert to normal sinus rhythm (NSR). A transesophageal echocardiogram was performed, followed by direct current cardioversion (DCCV) with 150 J. The patient remained symptom-free in NSR after the DCCV and was discharged on 40 mg enoxaparin. Patient informed consent was obtained for submission of this case report. CONCLUSION: This case illustrates the uncommon, yet acknowledged risk of corticosteroid-induced AF. There have been reported cases of AF in pregnant patients receiving both betamethasone and beta-mimetics; however, these case reports attribute the AF to the beta-mimetics. This is believed to be the first reported case of betamethasone-induced AF in pregnancy.