Arrhythmias and Pregnancy Management of Preexisting and New-Onset Maternal Arrhythmias Dominique S. Williams, MDa,*, Krasimira Mikhova, MDb, Sandeep Sodhi, MDc KEYWORDS Pregnancy Maternal arrhythmias Arrhythmias Atrial fibrillation Supraventricular tachycardia Ventricular tachycardia Structural heart disease KEY POINTS Women with preexisting arrhythmias are at high risk for recurrent arrhythmias and/or exacerbation arrhythmias with pregnancy. Arrhythmias may present at any time during pregnancy. Higher risk periods include the latter part of the second trimester, third trimester, and peripartum period. New-onset atrial fibrillation and ventricular arrhythmias should prompt evaluation for structural heart disease. BACKGROUND minute, and peripheral vascular resistance declines. These changes are amplified in multiple gestation Arrhythmias are the most common cardiovascular pregnancy, with cardiac output increasing by 60% complication of pregnancy. Hospitalizations due to 70%.2,3 Physiologic changes peak in the second to arrhythmias in pregnancy have increased by trimester, and again in labor and delivery where car- 58% from 2000 to 2012, mainly due to a rise in 1 diac output increases due to “auto transfusion” with atrial fibrillation. This rise is likely due to the in- uterine contractions. Sympathomimetic tone is also crease in pregnancy in women with structural increased due multiple factors including neurohor- heart disease. Arrhythmias may present for the monal changes during pregnancy, and pain and first time in pregnancy, and in women with a his- anxiety during labor and delivery.3,4 tory of arrhythmias, pregnancy may lead to an Cardiac myocytes have estrogen and proges- exacerbation of a previously controlled terone receptors. The downstream effects of es- arrhythmia. Identification and appropriate man- trogen and progesterone on cardiac myocytes is agement of arrhythmias are of utmost importance not well understood, but studies have shown these in order to optimize maternal and fetal health. hormones play a role in repolarization.4 Temporary cardiac remodeling during pregnancy may PATHOPHYSIOLOGY contribute to the development of arrhythmias. Cardiac output increases by 30% to 50% in preg- Atrial enlargement and stretch may create a sub- 5,6 nancy, heart rate increases by 10 to 15 beats per strate for atrial arrythmias. a Cardiovascular Division, John T. Milliken Department of Internal Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8086, St Louis, MO 63110, USA; b Cardiovascular Division, Electrophysiology, John T. Milliken Department of Internal Medicine, Washington University School of Medi- cine, 660 South Euclid Avenue, Campus Box 8086, St Louis, MO 63110, USA; c Department of Medicine, Cardio- vascular Division, John T. Milliken Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8086, St Louis, MO 63110, USA * Corresponding author. E-mail address: [email protected] Cardiol Clin 39 (2021) 67–75 https://doi.org/10.1016/j.ccl.2020.09.013 0733-8651/21/Published by Elsevier Inc. cardiology.theclinics.com Descargado para Irene Ramírez ([email protected]) en National Library of Health and Social Security de ClinicalKey.es por Elsevier en enero 08, 2021. Para uso personal exclusivamente. No se permiten otros usos sin autorización. Copyright ©2021. Elsevier Inc. Todos los derechos reservados. 68 Williams et al PREMATURE BEATS Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia Premature atrial and ventricular beats are common (AVRT) are the most common subtypes of SVT. in pregnancy, occurring in w59% of pregnancies 7 AVNRT is characterized by dual AV node physi- in one study. Premature beats are often benign ology allowing anterograde and retrograde con- and patient reassurance can be provided. Howev- duction. In AVRT conduction may occur through er, in some patients, premature beats can be asso- the AV node or the accessory pathway. In anti- ciated with structural heart disease and further dromic AVRT, the tachycardia conducts antero- workup and evaluation are prudent. grade down the accessory pathway and Premature ventricular contractions (PVC) may retrograde conduction through the AV node, be an initial presentation of a cardiomyopathy or creating a regular wide complex tachycardia. Anti- lead to the development of a cardiomyopathy. dromic AVRT accounts of 5% to 10% of AVRT.12 PVC burden has been shown to correlate with In patients with SVT, electrocardiograms in si- left ventricular function. Most cases of PVC- nus rhythm are assessed for preexcitation, which induced cardiomyopathy occur in patients with a may be asymptomatic and intermittently present PVC burden of greater than 10% in 24 hours.8 9 on electrocardiogram. Findings of preexcitation Tong and colleagues performed a prospective include a short PR interval less than 120 ms, case control study of 53 pregnancies in 43 women slurred upstroke of the QRS, and QRS prolonga- with a PVC burden of greater than 1%, mean PVC tion greater than 110 ms. Concern arises in pa- burden of 13.9%, and no structural heart disease. tients with preexcited atrial fibrillation that may PVCs presented more commonly in the first degenerate into ventricular fibrillation. Preexcita- trimester. In 25 of 53 pregnancies, beta-blocker tion should be considered in patients with SVT therapy was initiated due to symptoms and/or a who present with syncope or sudden cardiac high burden. Adverse cardiovascular events death. occurred in 11% of pregnancies and included heart failure, and sustained and nonsustained ven- tricular tachycardia. Pregnancies with adverse ATRIAL FIBRILLATION cardiovascular events all had a PVC burden of Atrial fibrillation (AF) is the most common greater than 5%. Adverse fetal events occurred arrhythmia in pregnancy, accounting for 27 per in 13% of pregnancies and included small for 9 100,000 pregnancy hospitalizations for arryth- gestational age and preterm birth. mias.1,13 In a meta-analysis of 7 studies totaling Patients with significant symptoms and pre- 8 301,638 pregnancies, AF incidence was signifi- served systolic function should be reassured. Med- cantly higher in women with structural heart dis- ical therapy for PVCs is indicated for symptoms or in ease compared with women without structural the setting of a reduced left ventricular ejection frac- heart disease (0.3% vs 2.2%).14 tion. First-line therapy with non-dihydropyridine cal- Risk factors for AF in pregnancy are similar to cium channel blockers or beta-blockers, excluding 8 risk factors in the nonpregnant state. Obesity and atenolol, is recommended. age older than 40 significantly increase risk of Premature atrial contractions (PACs) have primar- AF.15 Additional risk factors for AF identified in ily been studied in the nonpregnant population. the Registry of Pregnancy and Cardiac Disease Frequent PACs (>100 beats in 24 hours) have (ROPAC) include congenital heart disease, preex- been shown to increase the risk of new-onset atrial isting history of AF, beta-blocker use before preg- fibrillation, supraventricular tachycardia, and car- nancy, and valvular heart disease.16 diovascular morbidity and mortality in healthy pa- AF in pregnancy is associated with adverse tients and patients with multiple comorbidities. 10,11 maternal and fetal outcomes. Adverse fetal out- including structural heart disease. comes include intrauterine growth restriction, res- piratory distress syndrome, intraventricular SUPRAVENTRICULAR TACHYCARDIA hemorrhage, and higher rates of neonatal intensive care unit admissions. In addition, agents used for Supraventricular tachycardia (SVT) is the second rate control may lead to maternal hypotension most common arrhythmia in pregnancy, occurring and decreased placental perfusion, increasing in 22 per 100,000 pregnancy hospitalizations.1 the risk for preterm labor. Adverse maternal out- SVT may present at any stage of pregnancy, but comes include heart failure and thromboembolic commonly presents in the second trimester. SVT events.15–17 presents with sudden onset of palpitations, which Management of AF is similar to the nonpregnant may be associated with dyspnea, chest discom- state. In the nonpregnant population, trials have fort, or presyncope. not shown a difference in cardiovascular Descargado para Irene Ramírez ([email protected]) en National Library of Health and Social Security de ClinicalKey.es por Elsevier en enero 08, 2021. Para uso personal exclusivamente. No se permiten otros usos sin autorización. Copyright ©2021. Elsevier Inc. Todos los derechos reservados. Arrhythmias and Pregnancy 69 outcomes and overall mortality between rate and heart rate with pregnancy. During pregnancy, the rhythm control strategies.18,19 There are no data heart rate increases by 10 to 20 beats per minute available comparing maternal and fetal outcomes but the resting heart rate rarely exceeds greater in a rate control versus rhythm control approach. than 95 beats per minute.28 IST is characterized According to the 2018 European Society of Cardi- by an elevated resting heart rate greater than 100 ology Guidelines, a rhythm control strategy is beats per minute or an average heart rate of preferred for management of AF in pregnancy.20 greater than 90 beats per minute over 24 hours Rhythm control allows for lower doses of rate con- in the absence of secondary causes. Symptoms trolling medications, such as beta-blockers, which of IST include palpitations,