Palpitations during pregnancy are not an uncommon finding. However, arrhythmias requiring monitoring or treatment throughout the antepartum and peripartum periods are less frequent. Regardless, it is important for cardiologists to understand the risk factors for development of arrhythmias in patients of childbearing age throughout pregnancy, especially given the increasing prevalence of arrhythmias in pregnant patients during pregnancy.¹ An understanding of arrhythmia management is imperative during this vulnerable time given the need to consider safety for both the pregnant patient and the fetus. Individuals with a history of arrhythmia or inherited arrhythmia disorders also need to receive appropriate counseling prior to pregnancy.

The most common risk factor for an arrhythmia during pregnancy is a history of arrhythmia. Other common risk factors include advanced age, Black race, and lower socioeconomic status.^2,3 Recognition of arrhythmia is important, and pregnant patients require close monitoring because arrhythmia is associated with increased death rates, maternal complications, and fetal complications, with the most common adverse event being prematurity. This is influenced not only by the arrhythmia itself, but also treatment with medications such as anticoagulant or antiarrhythmic medications.

Pregnancy is associated with many hemodynamic and physiologic changes that can contribute to increased arrhythmia burden. These changes include increased myocardial stretch and remodeling due to increased blood volume, increased vasomotor sympathetic activity and baroreceptor sensitivity, increased resting heart rate with associated ion channel remodeling, and hormonal factors (i.e., increased estrogen and progesterone levels followed by a steep decline in the postpartum period).⁴ Combined, these factors can contribute not only to subjective sensation of palpitations but also to clinical arrhythmia.

Other than sinus tachycardia, supraventricular tachycardia is the most common arrhythmia observed during pregnancy.⁵ Although vagal maneuvers can be used in an attempt to control arrhythmias upon onset, pregnant patients with hemodynamically unstable or sustained arrhythmias may require direct electrical cardioversion or pharmacotherapy. No medications are without risk, but beta-blockers, such as metoprolol and propranolol, or digoxin are often safely used for rate control. Adenosine can be used in the acute setting. Flecainide and sotalol are often considered for a rhythm-control strategy, but amiodarone can be used in life-threatening situations, with cardioversion as necessary in more acute settings.^1,4 In pregnant patients with arrhythmias amenable to catheter ablation, waiting until the postpartum period to pursue ablation is preferable in an attempt to minimize radiation exposure to the fetus. If required, ablation can be considered during pregnancy, ideally after the first trimester, unless the procedure can be performed without fluoroscopy. There are limited data on the safety of direct oral anticoagulation medications in the setting of pregnancy; therefore, heparin (i.e., low molecular weight heparin [LMWH]) is preferred during pregnancy, as it does not cross the placenta. For patients deemed at high risk of thromboembolic events, warfarin is also used throughout pregnancy at dosages of <5 mg/day, or can be resumed in the second and third trimesters for pregnant patients requiring dosages of >5 mg/day, with use of LMWH during the first trimester.⁵ Information on the safety of medications during pregnancy and lactation can be found at LactMed®.⁶

Patients with a history of inherited arrhythmia disorders should have close monitoring throughout pregnancy and the postpartum period. This approach is particularly important for pregnant patients with long QT syndrome type 2, for whom cardiac events are most common in the postpartum period up to 40 weeks after delivery.⁵ Although there is no contraindication to pregnancy, patients with such history require counseling on associated risks and expectant management. Similarly, there is no contraindication to pregnancy in patients with a history of implantable cardiac device. Sudden cardiac death during pregnancy is rare; however, pregnant patients requiring resuscitation for any reason should receive routine advanced cardiac life support with special consideration to the gravid uterus with left uterine displacement to avoid compression of the aorta and vena cava.

Overall, the incidence of arrhythmia during pregnancy is increasing and patients with a history of arrhythmia or who develop arrhythmia during pregnancy require close monitoring. Although medical therapies are available, these are not without risk, and multidisciplinary care and coordination between obstetrics and cardiology is essential.

References

1. Park K, Bairey Merz CN, Bello NA, et al. Management of women with acquired cardiovascular disease from pre-conception through pregnancy and postpartum: JACC focus seminar 3/5. J Am Coll Cardiol 2021;77:1799-812.
2. Tamirisa KP, Elkayam U, Briller JE, et al. Arrhythmias in pregnancy. JACC Clin Electrophysiol 2022;8:120-35.
3. Vaidya VR, Arora S, Patel N, et al. Burden of arrhythmia in pregnancy. Circulation 2017;135:619-21.
4. Katsi V, Georgiopoulus G, Marketou M, et al. Atrial fibrillation in pregnancy: a growing challenge. Curr Med Res Opin 2017;33:1497-504.
5. Joglar JA, Kapa S, Saarel EV, et al. 2023 HRS expert consensus statement on the management of arrhythmias during pregnancy. Heart Rhythm 2023;20:e175-e264.
6. National Institute of Child Health and Human Development. Durgs and Lactation Database (LactMed®) (National Library of Medicine website). Available at: https://www.ncbi.nlm.nih.gov/books/NBK501922/. Accessed 09/13/2024.