differentiate during the period of organogenesis (gestational weeks 5 to 10) and are most susceptible to the effects of teratogens at that time. The major concern with antiarrhythmic drugs taken during the second and third trimesters are potential adverse effects on fetal growth and development, drug-related side effects in the neonate, risk of proarrhythmia, and possible effects on uterine contractility. Safety during pregnancy Safety profiles of antiarrhythmic drugs are drawn from case reports, case series, registry data, and case control and cohort studies of pregnant patients treated with these drugs, alone or with other agents, and for a variety of indications, including hypertension, maternal or fetal arrhythmias, and a wide spectrum of underlying medical disorders, which could confound findings. There are no data from large well-designed https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 12/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate randomized trials on which to base a recommendation for use of one drug over another. Data regarding both comparative efficacy in improving maternal outcome and fetal safety are inadequate for almost all antiarrhythmic drugs. Information related to the toxicity and teratogenicity of medications in pregnant patients must be interpreted in light of the background risk of adverse pregnancy outcomes in any pregnant woman. Major birth defects are defined as events of medical, surgical, or cosmetic significance. It is estimated that the prevalence of major birth defects is 2 to 4 percent among live born infants, and in utero growth restriction occurs in 3 to 10 percent of pregnancies, depending on the definition used. Intrauterine growth restriction can be related to in utero drug exposure, the mother's disease, other drug therapy, or a combination of these and other factors (eg, intrinsic fetal or placental factors). Since 1975, the United States Food and Drug Administration (FDA) has assigned pregnancy risk factors to all drugs available in the United States. Information on the use of specific drugs in pregnancy, including the FDA risk category and pregnancy implications, is available in the UpToDate drug database. Specific information on the fetal and neonatal risks of maternal drug ingestion during pregnancy and lactation are also available from the following website: www.perinatology.com/exposures/druglist.htm. The following table provides a brief synopsis of pregnancy and breastfeeding implications for the drugs discussed in this topic ( table 1). Pharmacokinetic changes during pregnancy Physiological changes during pregnancy may alter the absorption, excretion and effective plasma concentration of all antiarrhythmic drugs. Increased intravascular volumes during pregnancy may require an increase in loading dose. Gastrointestinal absorption of drugs may be altered by changes in gastric secretion and intestinal motility. Increase in renal blood flow and progesterone-induced increase of hepatic metabolism may augment drug clearance [71]. Finally, decreased serum protein concentrations may reduce protein binding, decreasing the total drug concentration and leading to greater fluctuation in unbound drug concentration. These pharmacokinetic changes may explain why pregnant patients previously stable on antiarrhythmic therapy have breakthrough arrhythmias. Because of intra-individual variability in the above-mentioned factors, drug dose should be optimized on an individual basis with monitoring of clinical response. Breast feeding In general, drugs that are most likely to be transferred from maternal plasma to milk have the following characteristics: nonionized, nonprotein bound, low molecular weight, high lipid solubility, and high pH. In addition to drug transfer, drug clearance in the setting of a https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 13/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate neonate's immature renal and hepatic function also determines whether a drug and/or its metabolites reach therapeutic or toxic levels in the infant. The LactMed database, produced by the National Library of Medicine, provides monographs on many prescription and over-the-counter medications. The database is available free of charge. The UpToDate drug database also provides information on lactation and breastfeeding implications for all drugs in the database. The following table provides a brief synopsis of pregnancy and breastfeeding implications for drugs discussed in this topic ( table 1). ISSUES REGARDING NON-PHARMACOLOGIC TREATMENT Electrical cardioversion Emergent or elective electrical cardioversion can be performed at all stages of pregnancy [13,14,72], and should be used for any sustained arrhythmia with hemodynamic compromise and can be considered for drug-refractory arrhythmias. Electrical cardioversion does not result in compromise of blood flow to the fetus [72]. While there is a theoretical risk of inducing an arrhythmia in the fetus, this risk is very small due to the high fibrillation threshold and small amount of energy reaching the fetus. Nonetheless, fetal rhythm monitoring is recommended because of reported cases of emergency cesarean delivery due to fetal arrhythmias [73]. In the third trimester, some physicians prefer to perform electrical cardioversion under general anesthesia and intubation, considering the more difficult airway and increased risk of gastric aspiration during pregnancy. Radiofrequency catheter ablation In nonpregnant patients, more definitive treatment of atrial fibrillation, atrial flutter, and other arrhythmias can be accomplished with catheter ablation. (See "Overview of catheter ablation of cardiac arrhythmias", section on 'Introduction'.) Catheter ablation prior to pregnancy is recommended in patients with symptomatic arrhythmias [11]. Ablation of atrial flutter and other arrhythmias is generally avoided during pregnancy given the need for fluoroscopy. For those experiencing new onset of arrhythmias suitable for radiofrequency ablation, or worsening of existing arrhythmias during pregnancy, ablation is generally delayed until after delivery. Experience with radiofrequency catheter ablation during pregnancy has been limited to cases of supraventricular tachycardia [53,56,74-81]. These procedures are generally not performed during pregnancy, mainly due to concerns of ionizing radiation exposure to the fetus. However, in rare cases, patients with severe and drug-resistant arrhythmias during pregnancy may be considered for an ablation procedure [11,13]. The risk of radiation exposure for the fetus during https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 14/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate a typical ablation is small (<1 mGy at all periods of gestation), and is mainly attributable to scatter from the thorax of the mother [82]. (See "Diagnostic imaging in pregnant and lactating patients".) Cases of successful ablation of atrial tachycardia using intracardiac echocardiography and electro-anatomic mapping without fluoroscopy have been reported [83,84]. SOCIETY GUIDELINE LINKS Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Atrial fibrillation" and "Society guideline links: Arrhythmias in adults".) SUMMARY AND RECOMMENDATIONS Symptoms Palpitations occur frequently during pregnancy and are a common indication for cardiac evaluation during pregnancy. (See 'Symptom-rhythm correlation' above.) Evaluation for structural heart disease Since cardiac arrhythmias are frequently associated with structural heart disease, any woman who presents with an arrhythmia during pregnancy should undergo clinical evaluation for structural heart disease. including an electrocardiogram and a transthoracic echocardiogram. (See 'Diagnostic testing' above.) Paroxysmal supraventricular tachycardia In pregnant patients with structurally normal hearts, paroxysmal supraventricular tachycardia (PSVT), including atrioventricular (AV)- nodal reentrant tachycardia and AV-reciprocating tachycardia, is the most common arrhythmia. Management of PSVT is performed with AV-nodal blocking agents. If hemodynamic compromise is evident, direct current (DC) cardioversion should be performed. (See 'Paroxysmal supraventricular tachycardia' above.) Atrial fibrillation and flutter These arrhythmias occur less frequently than PSVT and are more common in patients with structural heart disease. (See 'Atrial fibrillation and flutter' above.) Hemodynamically unstable pregnant patients require urgent cardioversion. (See 'Electrical cardioversion' above.) We suggest a rhythm control over a rate control strategy in pregnancy (Grade 2C). In pregnant patients, we use flecainide, propafenone, or sotalol ( table 1). (See 'Rhythm https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 15/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate control versus rate control' above.) If rhythm control cannot be achieved or is unlikely to be successful, then ventricular rate control can be instituted. Rate-control agents in pregnancy include beta-selective blockers, verapamil, and digoxin ( table 1), either alone or in combination. Although pregnancy is a prothrombotic state, given the lack of extensive data on risk stratification during pregnancy, similar recommendations for stroke risk assessment should be used as those in nonpregnant patients. (See "Atrial fibrillation in adults: Selection of candidates for anticoagulation".) The preferred anticoagulant for most pregnant patients is low molecular weight heparin. Heparin can be used throughout all stages of pregnancy but should be discontinued prior to delivery. (See 'Anticoagulation' above.) The labor and delivery plan Pregnant patients with arrhythmia should develop an early birth/labor plan with their multidisciplinary team including cardiology, OB-GYN, and anesthesia. A 12-lead electrocardiogram upon arrival to labor and delivery and telemetry may be indicated. (See 'Labor and delivery plan' above.) Information on the use of specific antiarrhythmic drugs in pregnancy is available in the UpToDate drug database. (See 'Issues regarding antiarrhythmic drug treatment' above.) Use of UpToDate is subject to the Terms of Use. REFERENCES 1. Siu SC, Sermer M, Colman JM, et al. Prospective multicenter study of pregnancy outcomes in women with heart disease. Circulation 2001; 104:515. 2. Drenthen W, Pieper PG, Roos-Hesselink JW, et al. Outcome of pregnancy in women with congenital heart disease: a literature review. J Am Coll Cardiol 2007; 49:2303. 3. Drenthen W, Boersma E, Balci A, et al. Predictors of pregnancy complications in women with congenital heart disease. Eur Heart J 2010; 31:2124. 4. Vaidya VR, Arora S, Patel N, et al. Burden of Arrhythmia in Pregnancy. Circulation 2017; 135:619. 5. Lee SH, Chen SA, Wu TJ, et al. Effects of pregnancy on first onset and symptoms of paroxysmal supraventricular tachycardia. Am J Cardiol 1995; 76:675. https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 16/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate 6. Silversides CK, Harris L, Haberer K, et al. Recurrence rates of arrhythmias during pregnancy in women with previous tachyarrhythmia and impact on fetal and neonatal outcomes. Am J Cardiol 2006; 97:1206. 7. Siu SC, Sermer M, Harrison DA, et al. Risk and predictors for pregnancy-related complications in women with heart disease. Circulation 1997; 96:2789. 8. Drenthen W, Pieper PG, Ploeg M, et al. Risk of complications during pregnancy after Senning or Mustard (atrial) repair of complete transposition of the great arteries. Eur Heart J 2005; 26:2588. 9. Drenthen W, Pieper PG, van der Tuuk K, et al. Cardiac complications relating to pregnancy and recurrence of disease in the offspring of women with atrioventricular septal defects. Eur Heart J 2005; 26:2581. 10. Drenthen W, Pieper PG, Roos-Hesselink JW, et al. Pregnancy and delivery in women after Fontan palliation. Heart 2006; 92:1290. 11. Brugada J, Katritsis DG, Arbelo E, et al. 2019 ESC Guidelines for the management of patients with supraventricular tachycardiaThe Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J 2020; 41:655. 12. Joglar JA, Page RL. Treatment of cardiac arrhythmias during pregnancy: safety considerations. Drug Saf 1999; 20:85. 13. Regitz-Zagrosek V, Roos-Hesselink JW, Bauersachs J, et al. 2018 ESC Guidelines for the management of cardiovascular diseases during pregnancy. Eur Heart J 2018; 39:3165. 14. Hindricks G, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J 2021; 42:373. 15. Silversides CK, Colman JM. Physiological changes in pregnancy. In: Heart disease in pregnan cy, 2nd ed, Oakley C, Warnes CA (Eds), Blackwell Publishing, Malden 2007. p.6. 16. Elkayam U, Gleicher N. Hemodynamics and cardiac function during normal pregnancy and p uerperium. In: Cardiac problems in pregnancy, 3rd ed, Elkayam U, Gleicher N (Eds), Wiley-Lis s, New York 1998. p.3. 17. Katz R, Karliner JS, Resnik R. Effects of a natural volume overload state (pregnancy) on left ventricular performance in normal human subjects. Circulation 1978; 58:434. https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 17/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate 18. Rubler S, Damani PM, Pinto ER. Cardiac size and performance during pregnancy estimated with echocardiography. Am J Cardiol 1977; 40:534. 19. Liebson PR, Mann LI, Evans MI, et al. Cardiac performance during pregnancy: serial evaluation using external systolic time intervals. Am J Obstet Gynecol 1975; 122:1. 20. Campos O. Doppler Echocardiography During Pregnancy: Physiological and Abnormal Findings. Echocardiography 1996; 13:135. 21. Franz MR, Cima R, Wang D, et al. Electrophysiological effects of myocardial stretch and mechanical determinants of stretch-activated arrhythmias. Circulation 1992; 86:968. 22. Wang Y, Joyner RW, Wagner MB, et al. Stretch-activated channel activation promotes early afterdepolarizations in rat ventricular myocytes under oxidative stress. Am J Physiol Heart Circ Physiol 2009; 296:H1227. 23. Ninio DM, Saint DA. The role of stretch-activated channels in atrial fibrillation and the impact of intracellular acidosis. Prog Biophys Mol Biol 2008; 97:401. 24. Kamkin A, Kiseleva I, Isenberg G. Stretch-activated currents in ventricular myocytes: amplitude and arrhythmogenic effects increase with hypertrophy. Cardiovasc Res 2000; 48:409. 25. Soliman EZ, Elsalam MA, Li Y. The relationship between high resting heart rate and ventricular arrhythmogenesis in patients referred to ambulatory 24 h electrocardiographic recording. Europace 2010; 12:261. 26. Zuspan FP. Catecholamines. Their role in pregnancy and the development of pregnancy- induced hypertension. J Reprod Med 1979; 23:143. 27. Natrajan PG, McGarrigle HH, Lawrence DM, Lachelin GC. Plasma noradrenaline and adrenaline levels in normal pregnancy and in pregnancy-induced hypertension. Br J Obstet Gynaecol 1982; 89:1041. 28. Whittaker PG, Gerrard J, Lind T. Catecholamine responses to changes in posture during human pregnancy. Br J Obstet Gynaecol 1985; 92:586. 29. Barron WM, Mujais SK, Zinaman M, et al. Plasma catecholamine responses to physiologic stimuli in normal human pregnancy. Am J Obstet Gynecol 1986; 154:80. 30. Ramsay MM, Broughton Pipkin F, Rubin PC. Pressor, heart rate and plasma catecholamine responses to noradrenaline in pregnant and nonpregnant women. Br J Obstet Gynaecol 1993; 100:170. 31. Roberts JM, Insel PA, Goldfien A. Regulation of myometrial adrenoreceptors and adrenergic response by sex steroids. Mol Pharmacol 1981; 20:52. https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 18/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate 32. Priori SG, Mantica M, Schwartz PJ. Delayed afterdepolarizations elicited in vivo by left stellate ganglion stimulation. Circulation 1988; 78:178. 33. Shotan A, Ostrzega E, Mehra A, et al. Incidence of arrhythmias in normal pregnancy and relation to palpitations, dizziness, and syncope. Am J Cardiol 1997; 79:1061. 34. Li JM, Nguyen C, Joglar JA, et al. Frequency and outcome of arrhythmias complicating admission during pregnancy: experience from a high-volume and ethnically-diverse obstetric service. Clin Cardiol 2008; 31:538. 35. Chang SH, Kuo CF, Chou IJ, et al. Outcomes Associated With Paroxysmal Supraventricular Tachycardia During Pregnancy. Circulation 2017; 135:616. 36. Tawam M, Levine J, Mendelson M, et al. Effect of pregnancy on paroxysmal supraventricular tachycardia. Am J Cardiol 1993; 72:838. 37. Smith WM, Gallagher JJ, Kerr CR, et al. The electrophysiologic basis and management of symptomatic recurrent tachycardia in patients with Ebstein's anomaly of the tricuspid valve. Am J Cardiol 1982; 49:1223. 38. Gleicher N, Meller J, Sandler RZ, Sullum S. Wolff-Parkinson-White syndrome in pregnancy. Obstet Gynecol 1981; 58:748. 39. Widerhorn J, Widerhorn AL, Rahimtoola SH, Elkayam U. WPW syndrome during pregnancy: increased incidence of supraventricular arrhythmias. Am Heart J 1992; 123:796. 40. Kounis NG, Zavras GM, Papadaki PJ, et al. Pregnancy-induced increase of supraventricular arrhythmias in Wolff-Parkinson-White syndrome. Clin Cardiol 1995; 18:137. 41. Murphy JJ, Hutchon DJ. Incessant atrial tachycardia accelerated by pregnancy. Br Heart J 1992; 68:342. 42. Treakle K, Kostic B, Hulkower S. Supraventricular tachycardia resistant to treatment in a pregnant woman. J Fam Pract 1992; 35:581. 43. Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2016; 67:e27. 44. Elkayam U, Goodwin TM. Adenosine therapy for supraventricular tachycardia during pregnancy. Am J Cardiol 1995; 75:521. 45. Ghosh N, Luk A, Derzko C, et al. The acute treatment of maternal supraventricular tachycardias during pregnancy: a review of the literature. J Obstet Gynaecol Can 2011; 33:17. https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 19/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate 46. Jaqueti J, Martinez-Hern ndez D, Hern ndez-Garcia R, et al. Adenosine deaminase in pregnancy serum. Clin Chem 1990; 36:2144. 47. Mariani PJ. Pharmacotherapy of pregnancy related SVT. Ann Emerg Med 1992; 21:229. 48. Byerly WG, Hartmann A, Foster DE, Tannenbaum AK. Verapamil in the treatment of maternal paroxysmal supraventricular tachycardia. Ann Emerg Med 1991; 20:552. 49. Halpern DG, Weinberg CR, Pinnelas R, et al. Use of Medication for Cardiovascular Disease During Pregnancy: JACC State-of-the-Art Review. J Am Coll Cardiol 2019; 73:457. 50. Bateman BT, Heide-J rgensen U, Einarsd ttir K, et al. -Blocker Use in Pregnancy and the Risk for Congenital Malformations: An International Cohort Study. Ann Intern Med 2018; 169:665. 51. Briggs GC, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation, 8th ed, Lippincott Willia ms & Wilkins, Philadelphia 2008. 52. Winniford MD, Fulton KL, Hillis LD. Long-term therapy of paroxysmal supraventricular tachycardia: a randomized, double-blind comparison of digoxin, propranolol and verapamil. Am J Cardiol 1984; 54:1138. 53. Szumowski L, Szufladowicz E, Orczykowski M, et al. Ablation of severe drug-resistant tachyarrhythmia during pregnancy. J Cardiovasc Electrophysiol 2010; 21:877. 54. Cruz FE, Cheriex EC, Smeets JL, et al. Reversibility of tachycardia-induced cardiomyopathy after cure of incessant supraventricular tachycardia. J Am Coll Cardiol 1990; 16:739. 55. Haines DE, DiMarco JP. Sustained intraatrial reentrant tachycardia: clinical, electrocardiographic and electrophysiologic characteristics and long-term follow-up. J Am Coll Cardiol 1990; 15:1345. 56. Pagad SV, Barmade AB, Toal SC, et al. 'Rescue' radiofrequency ablation for atrial tachycardia presenting as cardiomyopathy in pregnancy. Indian Heart J 2004; 56:245. 57. Gowda RM, Punukollu G, Khan IA, et al. Lone atrial fibrillation during pregnancy. Int J Cardiol 2003; 88:123. 58. Kuczkowski KM. New onset transient lone atrial fibrillation in a healthy parturient: d j vu. Int J Cardiol 2004; 97:339. 59. Autore C, Conte MR, Piccininno M, et al. Risk associated with pregnancy in hypertrophic cardiomyopathy. J Am Coll Cardiol 2002; 40:1864. 60. Walsh EP, Cecchin F. Arrhythmias in adult patients with congenital heart disease. Circulation 2007; 115:534. https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 20/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate 61. Tateno S, Niwa K, Nakazawa M, et al. Arrhythmia and conduction disturbances in patients with congenital heart disease during pregnancy: multicenter study. Circ J 2003; 67:992. 62. Balci A, Drenthen W, Mulder BJ, et al. Pregnancy in women with corrected tetralogy of Fallot: occurrence and predictors of adverse events. Am Heart J 2011; 161:307. 63. O'Riordan MN, Higgins JR. Haemostasis in normal and abnormal pregnancy. Best Pract Res Clin Obstet Gynaecol 2003; 17:385. 64. Kockova R, Kocka V, Kiernan T, Fahy GJ. Ibutilide-induced cardioversion of atrial fibrillation during pregnancy. J Cardiovasc Electrophysiol 2007; 18:545. 65. Burkart TA, Kron J, Miles WM, et al. Successful termination of atrial flutter by ibutilide during pregnancy. Pacing Clin Electrophysiol 2007; 30:283. 66. Tan HL, Lie KI. Treatment of tachyarrhythmias during pregnancy and lactation. Eur Heart J 2001; 22:458. 67. Giehm-Reese M, Kronborg MB, Lukac P, et al. Recurrent atrial flutter ablation and incidence of atrial fibrillation ablation after first-time ablation for typical atrial flutter: A nation-wide Danish cohort study. Int J Cardiol 2020; 298:44. 68. Davis MB, Walsh MN. Cardio-Obstetrics. Circ Cardiovasc Qual Outcomes 2019; 12:e005417. 69. Sharma G, Zakaria S, Michos ED, et al. Improving Cardiovascular Workforce Competencies in Cardio-Obstetrics: Current Challenges and Future Directions. J Am Heart Assoc 2020; 9:e015569. 70. Syme MR, Paxton JW, Keelan JA. Drug transfer and metabolism by the human placenta. Clin Pharmacokinet 2004; 43:487. 71. Dunlop W. Serial changes in renal haemodynamics during normal human pregnancy. Br J Obstet Gynaecol 1981; 88:1. 72. Wang YC, Chen CH, Su HY, Yu MH. The impact of maternal cardioversion on fetal haemodynamics. Eur J Obstet Gynecol Reprod Biol 2006; 126:268. 73. Barnes EJ, Eben F, Patterson D. Direct current cardioversion during pregnancy should be performed with facilities available for fetal monitoring and emergency caesarean section. BJOG 2002; 109:1406. 74. Bongiorni MG, Di Cori A, Soldati E, et al. Radiofrequency catheter ablation of atrioventricular nodal reciprocating tachycardia using intracardiac echocardiography in pregnancy. Europace 2008; 10:1018. 75. Risius T, Mortensen K, Meinertz T, Willems S. Cluster of multiple atrial tachycardias limited to pregnancy after radiofrequency ablation following senning operation. Int J Cardiol 2008; 123:e48. https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 21/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate 76. Kanjwal Y, Kosinski D, Kanj M, et al. Successful radiofrequency catheter ablation of left lateral accessory pathway using transseptal approach during pregnancy. J Interv Card Electrophysiol 2005; 13:239. 77. Bombelli F, Lagona F, Salvati A, et al. Radiofrequency catheter ablation in drug refractory maternal supraventricular tachycardias in advanced pregnancy. Obstet Gynecol 2003; 102:1171. 78. Dom nguez A, Iturralde P, Hermosillo AG, et al. Successful radiofrequency ablation of an accessory pathway during pregnancy. Pacing Clin Electrophysiol 1999; 22:131. 79. Berruezo A, D ez GR, Berne P, et al. Low exposure radiation with conventional guided radiofrequency catheter ablation in pregnant women. Pacing Clin Electrophysiol 2007; 30:1299. 80. Driver K, Chisholm CA, Darby AE, et al. Catheter Ablation of Arrhythmia During Pregnancy. J Cardiovasc Electrophysiol 2015; 26:698. 81. Chen G, Sun G, Xu R, et al. Zero-fluoroscopy catheter ablation of severe drug-resistant arrhythmia guided by Ensite NavX system during pregnancy: Two case reports and literature review. Medicine (Baltimore) 2016; 95:e4487. 82. Damilakis J, Theocharopoulos N, Perisinakis K, et al. Conceptus radiation dose and risk from cardiac catheter ablation procedures. Circulation 2001; 104:893. 83. Ferguson JD, Helms A, Mangrum JM, DiMarco JP. Ablation of incessant left atrial tachycardia without fluoroscopy in a pregnant woman. J Cardiovasc Electrophysiol 2011; 22:346. 84. Szumowski L, Szufladowicz E, Orczykowski M, et al. Ablation of severe drug-resistant tachyarrhythmia during pregnancy. J Cardiovasc Electrophysiol 2010; 21:877. Topic 13600 Version 31.0 https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 22/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate GRAPHICS Prevalence of arrhythmias during pregnancy in women with congenital heart disease AOS: aortic stenosis; ASD: atrial septal defect; AVSD: atrioventricular septal defect; CC-TGA: congenital corrected transposition of the great arteries; CHD: congenital heart disease; PAVSD: pulmonary atresia with ventricular septal defect; TGA: transposition of the great arteries; TOF: tetralogy of Fallot. Data from: Drenthen W, Pieper PG, Roos-Hesselink JW, et al. Outcome of pregnancy in women with congenital heart disease: a literature review. J Am Coll Cardiol 2007; 49:2303. Graphic 61986 Version 4.0 https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 23/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate Antiarrhythmic drugs in pregnancy Drug Pregnancy Breastfeeding Amiodarone Has been associated with serious adverse effects. Congenital Not recommended because of potential risk of hypothyroidism in goiter/hypothyroidism and hyperthyroidism can occur after in neonate. utero exposure. Other potential risks include prolonged QT interval in neonates. Beta blockers No evidence of increased risk of The AAP considers these agents teratogenesis, but some (particularly atenolol) may impair fetal growth when compatible with breastfeeding, but newborns should be observed for signs used for a prolonged duration in the second and third trimesters. Use only of beta blockade. Atenolol is a weak base that will accumulate in milk. Accumulation is in the third trimester is associated with reduced placental weight. enhanced by its water-soluble, low Newborns of patients taking these drugs near delivery are at risk of protein binding, little or no hepatic metabolism, and renal excretion bradycardia, hypoglycemia, and other symptoms of beta blockade. properties. Because it has been associated with beta-blocking effects and cyanosis in nursing infants, it is best avoided during breastfeeding. Among this class of drugs, atenolol appears to have the most unfavorable effect on birthweight. Sotalol Sotalol, which has both beta blocker Sotalol is concentrated in breast milk, and type III antiarrhythmic properties, with milk levels several-fold higher is not teratogenic, and its use has not been associated with fetal growth than those in maternal plasma, so close monitoring for bradycardia, restriction. Its use near birth has been associated with newborn bradycardia. hypotension, respiratory distress, and hypoglycemia is advised. Adenosine No evidence of increased risk of No information. Because of very short teratogenesis or increased risk of adverse fetal/neonatal effects. half-life, it is unlikely to have any adverse effects on the neonate. Digoxin No evidence of increased risk of The AAP considers digoxin compatible teratogenesis or increased risk of with breastfeeding. adverse fetal/neonatal effects. Verapamil No evidence of increased risk of teratogenesis or increased risk of The AAP considers verapamil compatible with breastfeeding. adverse fetal/neonatal effects. Procainamide No evidence of increased risk of teratogenesis or increased risk of The AAP classifies procainamide as compatible with breastfeeding. https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 24/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate adverse fetal/neonatal effects. However, the long-term effects of exposure in the nursing infant are unknown, particularly with respect to potential drug toxicity (eg, development of antinuclear antibodies and lupus-like syndrome). Quinidine No evidence of increased risk of teratogenesis. In therapeutic doses, The AAP considers quinidine compatible with breastfeeding. the oxytocic properties of quinidine have been rarely observed, but high doses can produce this effect and may result in preterm labor or abortion. Flecainide Developmental toxicity has been noted The AAP considers flecainide in animals, but there is limited compatible with breastfeeding. information on human risk from early pregnancy exposure. This risk appears to be low when used for refractory fetal arrhythmia. It may be the treatment of choice for tachycardia in hydropic fetuses. AAP: American Academy of Pediatrics. Adapted from: Briggs GG, Freeman RK, Ya e SJ. Drugs in Pregnancy and Lactation, 8th edition. Philadelphia: Lippincott Williams & Wilkins. Graphic 50716 Version 8.0 https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 25/26 7/6/23, 1:50 PM Supraventricular arrhythmias during pregnancy - UpToDate Contributor Disclosures Candice Silversides, MD, MS, FRCPC No relevant financial relationship(s) with ineligible companies to disclose. Louise Harris, MBChB No relevant financial relationship(s) with ineligible companies to disclose. Sing-Chien Yap, MD, PhD Grant/Research/Clinical Trial Support: Medtronic [Ventricular arrhythmias]. Consultant/Advisory Boards: Boston Scientific [Ventricular arrhythmias]. All of the relevant financial relationships listed have been mitigated. Hugh Calkins, MD Grant/Research/Clinical Trial Support: Adagio Medical [Atrial fibrillation]; Boston Scientific [ARVC]; Farapulse [Atrial fibrillation]; Medtronic [Atrial fibrillation]. Consultant/Advisory Boards: Abbott [Atrial fibrillation]; Atricure [Atrial fibrillation]; Biosense Webster [Catheter ablation]; Boston Scientific [ARVC and atrial fibrillation]; Medtronic [Atrial fibrillation]; Sanofi [Atrial fibrillation]. Other Financial Interest: Atricure [Lecture honoraria]; Biosense Webster [Lecture honoraria]; Boston Scientific [Lecture honoraria]; Medtronic [Lecture honoraria]. All of the relevant financial relationships listed have been mitigated. N A Mark Estes, III, MD Consultant/Advisory Boards: Boston Scientific [Arrhythmias]; Medtronic [Arrhythmias]. All of the relevant financial relationships listed have been mitigated. Nisha Parikh, MD, MPH No relevant financial relationship(s) with ineligible companies to disclose. Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence. Conflict of interest policy https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy/print 26/26