New-onset lone maternal atrial fibrillation: A case report.

Rationale: Atrial fibrillation (AF) is encountered rarely in pregnancy. Management of maternal AF is challenging as it poses a threat to both maternal and fetal well-being.

Patient Concerns: We report a case of a 35 weeks pregnant woman who presented in emergency with sudden-onset palpitations and mild shortness of breath with no personal/family history of cardiac diseases.

Diagnoses: Patient's pulse was irregularly irregular with an average rate of 179 beats per minute. The obstetric examination was normal.

Diagnosis: High-sensitive cardiac troponin T (hs-cTnT) was elevated. The 12 lead electrocardiogram (ECG) confirmed AF. The obstetric ultrasound, electronic fetal heart rate (EFHR) trace, and maternal echocardiography were normal.

Interventions: The patient was admitted under joint cardiology and obstetric care and monitored with continuous telemetry. She was commenced on a therapeutic dose of low-molecular weight heparin (LMWH) and intravenous fluid. She received a single 200 Joule synchronized direct current (DC) shock under general anesthesia in operation theater, which reverted the rhythm back to normal. EFHR monitoring was normal pre- and post-DC cardioversion. We acknowledge the unwise use of therapeutic dose of LMWH before DC cardioversion (DCCV) because of a potential need for emergency cesarean delivery for maternal and/or fetal compromise.

Outcome: The patient remained well and in sinus rhythm after cardioversion. She was discharged home the following day on Flecainide (anti-arrhythmic) and therapeutic dose of low molecular weight heparin (LMWH) and followed up in outpatient clinics frequently. She had a baby at term and received prophylactic LMWH for 10 days post-cesarean. She was discharged from cardiology clinic when she was 10 weeks postnatal, and Flecainide was discontinued.

Lessons: We are reporting this case because of the rarity of the condition and successful use of DCCV for treating maternal AF. High-sensitive cardiac troponin T (hs-cTnT) level is a useful laboratory indicator to gauge the severity of AF in pregnancy. We emphasize to make the arrangements for EFHR monitoring and potential cesarean delivery and advocate cautious use of thromboprophylaxis while planning for electrical cardioversion (ECV) for maternal AF.