Atrial Fibrillation in a Structurally Normal Heart during Pregnancy: A Review of Cases From a Registry and From the Literature.

OBJECTIVES

Atrial fibrillation (AF) in a structurally normal heart is rare during pregnancy. We wished to use our experience to expand the literature on the causes and management of this condition.

METHODS

All members of Groupe d'Étude en Médecine Obstétricale du Québec (GÉMOQ) were invited to record cases of AF in a structurally normal heart during pregnancy to the group's Registry. We searched Medline, PubMed, and Google Scholar (1946 to 15 April 2016) for relevant articles using the key words "atrial fibrillation" and "pregnancy."

RESULTS

Sixteen pregnancies with AF in 12 women were recorded in the Registry, and 19 pregnancies with AF in 18 women were retrieved from the literature. The majority (94% in the Registry and 89% in the literature) presented with paroxysmal AF. We found differences between characteristics recorded in the literature and in the Registry; these were the presence of classic triggers for AF (37% in the literature vs. 0% in the Registry), the rate of recurrence of AF in the same pregnancy (5% vs. 31%) or in subsequent pregnancies (1 vs. 4), the rate of spontaneous cardioversion (50% vs. 81%), the use of acetylsalicylic acid and/or low molecular weight heparin as stroke preventive therapy (35% vs. 71%), and the rate of AF influencing the decision to deliver (21% vs. 6%). One woman in the Registry with persistent AF had a left atrial appendage thrombus.

CONCLUSION

The GÉMOQ's Registry added 12 cases (16 pregnancies) to the existing literature. AF during pregnancy is an arrhythmia that is mainly unprovoked, paroxysmal, and stable, with spontaneous cardioversion occurring usually within 24 hours. It is associated with good pregnancy outcomes.