A Case of Tachycardia-Induced Cardiomyopathy During Pregnancy: Clinical Presentation and Management

A 28-year-old G2P0010 woman with a history of COVID infection during her current pregnancy treated with monoclonal antibodies and benign gestational thrombocytopenia presented for routine prenatal care at 33 weeks' gestation. The patient was asymptomatic, but incidental tachycardia was noted on the physical exam with an irregular rhythm. An electrocardiogram (ECG) was performed and was consistent with multifocal atrial tachycardia at a rate of 144 beats per minute. The patient was started on labetalol 50 mg daily and was referred to cardiology for consultation. An echocardiogram was performed and showed dilated left ventricular cavity with a moderately reduced ejection fraction of 40%. No previous echocardiogram was available for comparison; the patient had no history of cardiac disease. The dose of labetalol was increased to 50 mg twice daily and she was admitted for digoxin loading and titration. Though fetal tolerance was excellent, her heart rate was not controlled. Digoxin was switched to flecainide and labetalol was switched to metoprolol which improved her heart rate and repeat echocardiogram showed an ejection fraction of 50%. The patient was admitted for induction of labor at 39 weeks of gestation and continued intrapartum flecainide. Metoprolol was continued intra and postpartum. Flecainide was resumed at three days postpartum due to the recurrence of atrial tachycardia and has been maintained. A repeat echocardiogram is scheduled six weeks postpartum to evaluate left ventricular function and wean off antiarrhythmics.