2023 HRS Expert Consensus Statement on the Management of Arrhythmias During Pregnancy (2023)

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

Atrial fibrillation is increasingly becoming the most common newly diagnosed sustained arrhythmia during pregnancy. Some therapeutic decisions for atrial fibrillation, such as a

In scenarios where there is significant hemodynamic compromise, such as rapid VT or certain unstable forms of SVT, the priority is to restore normal hemodynamics; thus, direct current cardioversion should be performed in pregnant patients following the same resuscitation algorithms as in the general population, without delay out of concern for potential harm to the fetus.^155,162 There is no evidence to support the use of difference shock energy outputs, other than what is already used

1.Sustained arrhythmias during pregnancy increase the risk of hemodynamic instability. Although regional anesthesia is generally preferred during pregnancy to avoid more difficult airway management and, theoretically, to optimize fetal/neonatal risks,¹⁷¹ general anesthesia for cardiac procedures will optimize oxygenation during hemodynamic instability. When general anesthesia is planned, expertise in safe obstetric general anesthetic administration is optimal.¹⁷²

Aortocaval compression occurs as

Pregnancy in healthy individuals is associated with an increase in sinus rhythm frequency and slight increase in extrasystole burden, which return to prepregnancy levels postpartum. In general, resting heart rate increases by 10% or more during pregnancy due to autonomic, hemodynamic, and whole-body volume fluctuations. Patients with extrasystole or sinus tachycardia on ECG documented during ongoing symptoms generally do not benefit from further extensive evaluation. In a study of 110 pregnant

The evidence supporting the value of detailed history, physical examination, targeted blood testing, and resting 12-lead ECG in nonpregnant patients presenting with syncope has been recently reviewed in the 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients with Syncope¹⁸ and in the 2018 ESC Guidelines for the Diagnosis and Management of Syncope.¹³ In pregnant patients, although specific studies do not exist and pregnancy is a frequent exclusion criterion in clinical

SVT may be secondary to atrial tachycardia (AT), AV nodal reentry tachycardia, or AV reciprocating tachycardia, with an accessory pathway either overt or concealed. For both AV nodal reentry tachycardia and AV reciprocating tachycardia, the AV node is a required component of the reentrant circuit, and maneuvers or medications that slow AV conduction can terminate the SVT. Vagal maneuvers, such as the Valsalva maneuver or carotid sinus massage, are simple methods for terminating SVT and are safe

Occasionally, PACs are associated with intolerable symptoms during pregnancy and therapy is necessary. The studies on the treatment of PACs during pregnancy involve a beta-blocker, either metoprolol or propranolol.^64,162,234 Atenolol is best avoided during pregnancy because it is associated with lower birth weight when compared with other agents.

PACs are common during pregnancy and are very rarely associated with adverse events in the mother or the fetus.³³ PACs do not require treatment unless

Cardioversion is generally safe during pregnancy. The majority of data show no adverse effects to the fetus with direct current cardioversion.²⁴⁵ Any possible risks that may be imposed by shocks are generally balanced against the importance of restoring baseline maternal hemodynamics.

Retrospective database evaluations and case reports show relative safety and tolerance for the acute use of intravenous beta-blockers, digoxin, and/or calcium channel blockers for rate control in AF/AFL with RVR

Direct current cardioversion is generally safe during pregnancy and effective particularly in cases of hemodynamic compromise. The majority of data show no adverse effects to the fetus with direct current cardioversion.^245,270,291 Furthermore, literature in the ICD population also supports the lack of significant risk to the fetus with maternal ICD shocks.²⁶⁹ Any possible risk to the fetus that may be imposed by shocks must be balanced against the importance of restoring baseline maternal

Although in a majority of pregnant patients who present with advanced heart block the etiology is congenital, other diagnostic possibilities must be excluded. Transthoracic echocardiography can reveal conditions such as cardiomyopathy, valvular disease, congenital defects, tumors, infiltrative processes, and pericardial and great vessel abnormalities.^29,308 Cardiac magnetic resonance is particularly useful if additional information is required to identify infiltrative disease processes in

Recognition of women at risk of clinical deterioration allows for initiation of monitoring and the opportunity for cardiovascular stabilization, resulting in significant reductions in maternal morbidity. The clinical criteria to be monitored include maternal heart rate >130/min, respiratory rate >30/min, mean arterial pressure <55 mmHg, oxygen saturation <90%, abnormal body temperature, fetal heart rate >160/min, altered mental status, and pain out of proportion to stage of labor.³¹³

Patients with CHD are at higher risk of maternal and fetal complications, morbidity, and mortality during pregnancy than individuals without heart disease,^46,332 and Drenthen et al³³¹ noted that the most common complications of pregnant patients with CHD include arrhythmias and heart failure. Thus, it is important to have clear discussions regarding risks of pregnancy and to take steps to mitigate these risks with patients who have CHD and arrhythmias before they become pregnant.

A systematic

Several case reports and nonrandomized retrospective studies have found that intermittent AFL (<50% of the time or <12 hours per day) in fetuses with no evidence of hydrops on fetal ultrasound or fetal echocardiogram is well tolerated with good outcomes.^232,381 Cuneo et al⁷⁴ found that in 15 fetuses with intermittent tachycardia, none progressed to sustained tachycardia or heart failure. Management of intermittent AFL with frequent monitoring is generally sufficient and is less risky to the

In the majority of cases of sustained VT, ​the first-line therapy for the fetus includes maternal intravenous magnesium and lidocaine. Limiting maternal magnesium to <48 hours duration¹³⁴ reduces the risk of maternal toxicity. ​Monitoring of magnesium levels is advisable, and magnesium may be redosed if there is recurrent VT as long as maternal magnesium levels are <6 mEq/L. In some reports, oral propranolol and mexiletine therapy have also been used as first-line agents for this indication.^128,

While maternal antibody levels can fluctuate, when anti-Ro and anti-La antibodies are present in pregnancies complicated by autoimmune or rheumatologic conditions, fetuses are at risk for the development of cardiac complications, such as isoimmune heart block, hydrops, and cardiomyopathy, including endocardial fibroelastosis independent of conduction system involvement. Pregnancies with prior history of fetal/neonatal isoimmune cardiac disease have at least a 10% risk of recurrence.⁴¹¹

Genetic testing results can predict severity of presentation, influence choice of antiarrhythmic drugs, and assist risk stratification for an affected fetus, as well as the pregnant patient, if affected.429, 430, 431, 432 The risk of stillbirth and the incidence of fetal and neonatal life-threatening IAS-related rhythms vary with genotype; for SCN5A, phenotypic expression in the fetus and neonate can vary widely.^{77,79,153,154,407,429,430,}433, 434, 435, 436, 437, 438 Of women with prior

A number of retrospective studies have shown reduced events in women with LQTS who are treated with beta-blockers during pregnancy and the postpartum period.^423,444, 445, 446 Although these are not randomized, the demonstration of serious adverse events in these studies, including cardiac arrest and death, highlight the risk for both mother and fetus/baby. Guidelines recommend longer-acting beta-blockers (eg, nadolol and sustained-release propranolol).^15,24,27,69 Data are insufficient regarding

Fetal echocardiography can determine some features of fetal conduction, and most importantly, can detect structural and functional heart conditions, such as hydrops fetalis, LV dysfunction, cardiomyopathy, LV noncompaction, and structural cardiac defects. Anomalies of structure and function are particularly common in fetuses that present with severe symptoms.⁴³² Fetal echocardiography is readily available and assesses fetal heart rate and rhythm, isovolumic relaxation time, and whether