Abstract

37-year-old Caucasian lady presented to ANC at 19⁺⁰/40 with AF that had been diagnosed in A&E at 12 weeks after presenting with a UTI. She had one previous term vaginal delivery, was a non-smoker, HR 100bpm and normal TFTs.

She was commenced on low dose aspirin, booked for an ECHO and joint Obstetric and Cardiology follow-up with serial growth scans. She remained obstetrically well.

In Cardiology clinic at 29 weeks her AF persisted and bisoprolol 2.5mg was commenced, increasing to 5mg after one week. At 35 weeks the ECHO showed better rate control and normal cardiac function.

She was admitted to LW at 36⁺⁰ weeks with IUGR. Cardiac assessment was normal, and she was induced with a planned limited second stage. Pushing was associated with light-headedness and tachycardia but she declined an instrumental delivery.

Post delivery she showed signs of cardiac decompensation. Cardiology team recommended further bisoprolol, and digoxin if ongoing evidence of cardiac failure. Her symptoms settled and she remained well postnatally. She was discharged on warfarin, and cardiology follow-up for cardioversion.

Physiological changes in pregnancy can predispose women to arrhythmias, and increased morbidity and mortality due to complications (heart failure, PE, IUGR). AF is rare without an underlying cardiac abnormality (congenital or valvular), or metabolic disturbance (thyrotoxicosis, electrolyte abnormality).2 2

Objectives of pregnancy management include rate control, cardioversion if haemodynamically unstable, and thromboprophylaxis (not in lone AF).3

Therapeutic treatment must be balanced with the risks to the fetus: Beta-blockers (IUGR, fetal bradycardia, hypoglycaemia), Digoxin (IUGR, preterm labour).4