RESUMO
BACKGROUND: De novo atrial fibrillation (AF) is rare in pregnancy. The exact pathophysiology of AF is unclear; it might be caused by several cardiovascular and hemodynamic changes that occur in pregnancy, leading to an increased stretch in myocardial cells of the atrial wall. CASE DESCRIPTION: A 26-year-old primigravida with a thus far uncomplicated pregnancy presents with symptoms of heart palpitations, shortness of breath and chest pain. The CTG was normal but an ECG showed de novo atrial fibrillation. The patient was given two doses of digoxin 0.25mg after which sinus rhythm was achieved. No anatomical substrate was found; hence it was seen as most likely caused by increased hemodynamic demands in pregnancy. The delivery and postpartum period were uncomplicated. CONCLUSION: AF is rarely seen in pregnancy. Treatment favours rate and/or rhythm control with metoprolol and digoxin, respectively. Anticoagulation is not indicated in lone AF during pregnancy. Vaginal birth is preferred.