Management of Arrhythmias During Pregnancy

1. The most common arrhythmias seen in pregnant patients are generally benign, including sinus arrhythmia, supraventricular tachycardia (SVT), and premature beats, whereas life-threatening arrhythmias, such as hemodynamically significant supraventricular tachycardia or ventricular tachycardia (VT), are significantly less common.

2. Atrial fibrillation (AF) is increasingly becoming the most common newly diagnosed sustained arrhythmia during pregnancy. Some therapeutic decisions for atrial fibrillation, such as a rate-control strategy versus rhythm control strategy, should be based on hemodynamic tolerance and underlying substrate as in nonpregnant patients, whereas others, such as anticoagulation therapy protocols, are specific to pregnancy.

3. Care of arrhythmias in the pregnant patient should involve a multidisciplinary engagement of cardiologists and/or electrophysiologists, pediatric electrophysiologists, maternal-fetal medicine subspecialists, anesthesiologists, and neonatologists to optimize outcomes for both the mother and the fetus/newborn.

4. When arrhythmias occur in pregnancy, both the mother and the fetus may be affected; thus, shared decision-making should include a discussion of the risks and benefits to both the mother and the fetus of antiarrhythmic drugs, specific procedures, and monitoring, as well as the risks of withholding such therapies.

5. Fetal arrhythmia management decisions should be considered in the context of any concomitant maternal arrhythmias or diagnoses (eg, fetal bradycardia in mothers with long QT syndrome [LQTS]). Treatment of fetal arrhythmias generally involves either maternal systemic administration of antiarrhythmic agents; rarely, such as in cases of fetal hydrops, direct fetal intramuscular (IM) injection or intraperitoneal injection of antiarrhythmic drugs may be necessary.

6. Management of hemodynamically significant maternal arrhythmias should emphasize the prompt use of the most effective therapy available (cardioversion, antiarrhythmic drug infusion, or catheter ablation) to terminate the ongoing arrhythmia and/or prevent recurrent arrhythmias, with appropriate fetal monitoring, and measures to minimize radiation exposure when catheter ablation is pursued.

7. Procedures such as catheter ablation and implantable devices, if indicated for arrhythmias with hemodynamic compromise or for sudden death prevention, can be performed at experienced centers with maximum possible mitigation of radiation exposure to the fetus, which is best achieved by overall reduction of total maternal radiation, since covering the maternal abdomen with a lead apron alone is generally of no benefit.

8. Due to the overall risk of aortocaval compression in pregnant patients, particularly in the third trimester, avoidance of prolonged supine positioning is warranted, especially during invasive procedures, with preference given to a left lateral tilt position to optimize hemodynamics.

9. Use of antiarrhythmic drugs during pregnancy and the postpartum period should largely be similar to use in nonpregnant patients with some exceptions for the sake of fetal safety: selecting drugs with the longest record of safe use during pregnancy and lactation; using the lowest effective dose; and periodically reevaluating the continued need for the same dose/type of antiarrhythmic, including during the postpartum period, in light of potential drug concentration in breast milk.

10. For parents with a suspected or known inherited arrhythmia syndrome, genetic screening and counseling should be provided, ideally by genetic counselors or providers who are trained or specialize in genetics, to assess potential fetal risks and for therapeutic optimization.