The Challenge of Managing Atrial Fibrillation during Pregnancy

Abstract

The incidence of atrial fibrillation (AF) during pregnancy increases with maternal age and with the presence of structural heart disorders. Early diagnosis and prompt therapy can considerably reduce the risk of thromboembolism. The therapeutic approach to AF during pregnancy is particularly challenging, and the maternal and fetal risks associated with the use of antiarrhythmic and anticoagulant drugs must be carefully evaluated. Moreover, the currently used thromboembolic risk scores have yet to be validated for the prediction of stroke during pregnancy. At present, electrical cardioversion is considered to be the safest and most effective strategy in women with hemodynamic instability. Beta-selective blockers are also recommended as the first choice for rate control. Antiarrhythmic drugs such as flecainide, propafenone and sotalol should be considered for rhythm control if atrioventricular nodal-blocking drugs fail. AF catheter ablation is currently not recommended during pregnancy. Overall, the therapeutic strategy for AF in pregnancy must be carefully assessed and should take into consideration the advantages and drawbacks of each aspect. A multidisciplinary approach with a "Pregnancy-Heart Team" appears to improve the management and outcome of these patients. However, further studies are needed to identify the most appropriate therapeutic strategies for AF in pregnancy.

Keywords: Pregnancy Heart Team; antiarrhythmic drugs (AADs); anticoagulants; atrial fibrillation (AF); electrical cardioversion (ECV); pregnancy.

Fig. 1.

Clinical risk factors for atrial fibrillation (AF) during pregnancy. AF during pregnancy generally indicates an underlying congenital or acquired heart disease. Cardiovascular risk factors such as obesity, chronic hypertension and diabetes have been associated with AF during pregnancy. Moreover, AF is more frequent in older women ($>$41 years), women of African-American ancestry, and women with lower socioeconomic status. Drug toxicity, pulmonary embolism, accessory pathways, re-entrant circuits, hyperthyroidism, and electrolyte imbalance have also been associated with the development of AF during pregnancy.

Fig. 2.

Pathophysiology of atrial fibrillation (AF) in pregnancy. Several neurohormonal and hemodynamic changes characterize pregnancy, including vasodilation, neurohormonal activation, enhanced sympathetic tone, and increased resting heart rate and total blood volume.

Fig. 3.

Rhythm control and rate strategy for atrial fibrillation (AF) in pregnancy. Rhythm control should be the preferred treatment strategy during pregnancy. If rate control is chosen, $\beta$-blockers should be the first line of therapy, with digoxin, verapamil or diltiazem as the second choice.

Fig. 4.

Proposed strategy for atrial fibrillation (AF) management in pregnancy. Hemodynamic condition is the most important factor for determining the appropriate management of AF in pregnancy. Electrical cardioversion (ECV) should be performed promptly if there is hemodynamic instability or if the arrhythmias present a risk to the mother and/or fetus. The ECV option may also be considered for stable patients. ECV during pregnancy is relatively safe at all stages of pregnancy when using a synchronized external direct current (50–100 J biphasic shocks for AF, and 25–50 J for atrial flutter), and with monitoring of the fetal heart rate during cardioversion. In stable patients with structurally normal hearts, a pharmacologic cardioversion attempt can be performed safely using intravenous flecainide [71]. *Flecainide is relatively contraindicated in women with structural heart disease, and is also contraindicated in case of atrial flutter due to risk of 1:1 AV conduction. LMWH, low-molecular-weight-heparin; AV, aortic valve.