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

Authors, Journal, Affiliations, Type, DOI

• Chair: José A. Joglar, MD, FHRS (UT Southwestern); Vice-Chairs: Suraj Kapa (Mayo Clinic), Elizabeth V. Saarel (St. Luke's/Cleveland Clinic)
• Writing committee of 20 experts from 6 countries across electrophysiology, cardiology, pediatric EP, MFM, gynecology/obstetrics
• Endorsed by: ACC, ACOG, AHA, APHRS, EHRA, LAHRS, PACES, SMFM
• Journal: Heart Rhythm 2023;20:e175–e259 (October 2023)
• Type: International multi-society expert consensus statement (163 recommendations; mean consensus 98.4%; 123/163 with 100% consensus)
• DOI: https://doi.org/10.1016/j.hrthm.2023.05.017

Overview

This is the first dedicated international expert consensus document on the management of cardiac arrhythmias during pregnancy, covering both the mother and the fetus across all arrhythmia types. It synthesises evidence from MEDLINE, PubMed, Embase, and Cochrane across randomised trials, registries, case series, and case reports (given the limited RCT evidence in this field). The document provides 163 formal recommendations with Class of Recommendation (COR) and Level of Evidence (LOE), supported by decision algorithms for each arrhythmia type. It supersedes and consolidates the fragmented pregnancy arrhythmia guidance previously embedded in broader non-pregnant-focused guidelines.

Keywords

Antiarrhythmic; Atrial fibrillation; Bradyarrhythmia; Fetal arrhythmia; Inherited arrhythmia syndrome; Maternal arrhythmia; Pregnancy; Supraventricular tachycardia; Tachyarrhythmia; Ventricular tachycardia

Key Takeaways

Epidemiology of Arrhythmias in Pregnancy

• Overall prevalence of arrhythmias among pregnancy-related hospitalisations: 68–166 per 100,000 admissions
• Most common arrhythmias: sinus arrhythmia (60% of diagnoses), PAC/PVC (19%), PSVT (14%); AF (27/100,000), SVT (22/100,000), VT (16/100,000), VF (2/100,000)
• PACs/PVCs: present in 50–60% of patients with palpitations; generally resolve spontaneously after delivery
• In-hospital death with arrhythmia: 5.9% vs 0% without; perinatal complications 36.5% vs 21.8%
• Arrhythmias more common in Black women (116 vs 73 per 100,000); increase with maternal age and comorbidities (obesity, HTN, DM)
• Syncope incidence: 1% (9.7/1,000 pregnancies); most commonly vasovagal; cardiac syncope <1–2% of all syncope but highest-risk
• Only 10% of palpitation episodes during pregnancy are associated with a documented arrhythmia on 24-hour Holter

Pathophysiology of Arrhythmogenesis in Pregnancy

• Blood volume ↑50% (up to 100% in twin pregnancies) → cardiac chamber dilation → stretch-activated ion channels → spatial dispersion of refractoriness
• HR ↑10–20 bpm (autonomic shift toward sympathetic dominance)
• Estradiol and progesterone increase adrenergic receptor number and responsiveness → arrhythmogenic
• Hormonal changes lengthen reentrant pathways → facilitate reentrant arrhythmias

Antiarrhythmic Drugs in Pregnancy — General Principles

• Pharmacokinetic changes in pregnancy require attention: volume of distribution increases, clearance changes; drug levels or physiological effects (e.g., QT monitoring) should be tracked
• Beta-blockers: associated with intrauterine fetal growth restriction; atenolol has former FDA category D rating and is best avoided; growth restriction <200 g in most cases (clinically insignificant in most contexts)
• Nadolol: concentrates highly in breast milk (high risk for neonatal accumulation); if breastfeeding, prefer propranolol or metoprolol unless rhythm stability in LQTS requires it
• FDA 2015 Pregnancy and Lactation Labeling Rule replaced alphabet categories (A/B/C/D/X) with individualized narrative summaries; human data available in <20% of new labels
• During lactation: medication choice should balance maternal indication, efficacy, and infant exposure via breast milk
• Amiodarone in pregnancy: associated with fetal thyroid disorders, bradycardia, growth restriction, neonatal adverse effects — reserve for refractory cases; short-term exposure preferable to long-term

Key Drug Safety Profile in Pregnancy

Procedural Considerations

Cardioversion

• Safe and effective at all stages of pregnancy; same energy levels as non-pregnant patients
• Fetal heart rate monitoring advised after cardioversion if fetal viability reached
• Electrode placement: avoid breast tissue to maximise current delivery; sterno-apical for VT, antero-posterior for atrial arrhythmias
• Immediate cardioversion for hemodynamically unstable arrhythmias — should not be withheld due to pregnancy

Catheter Ablation

• Feasible during pregnancy, ideally after first trimester; modern 3D mapping systems allow zero-fluoroscopy procedures
• Fetal radiation dose from typical SVT ablation: well below 50 mGy negligible-risk threshold for lifetime malignancy
• Lead apron over pelvis: only 3% reduction in fetal radiation dose (scatter from thorax, not direct beam) — limited benefit
• Zero-fluoroscopy ablation increasingly used even for complex procedures

Anesthesia

• Regional anesthesia generally preferred; general anesthesia may be needed for hemodynamic instability
• Left lateral tilt (≥30°) or manual uterine displacement required to relieve aortocaval compression (from ~20 weeks)
• Multiple perioperative drugs prolong QT (Table 6): ondansetron, ketamine, sevoflurane, pancuronium — careful selection required in LQTS
• Cricoid pressure no longer favoured; rapid sequence induction for general anaesthesia

Aortocaval Compression

• Inferior vena cava compression begins at 20 weeks; severe obstruction at term
• Left lateral tilt ≥30° significantly improves cardiac output and IVC volume
• Avoid prolonged supine positioning, especially in third trimester and during procedures

Section 5–6: Palpitations and Syncope

• Palpitations evaluation: 12-lead ECG; Holter/event monitor; targeted echo; exclude non-cardiac causes
• Syncope classification in pregnancy unique: includes supine hypotensive syndrome (IVC compression in supine position)
• Vasovagal syncope most common in pregnancy; cardiac syncope rare but high risk
• Sudden LOC without prodrome in patient with pre-existing tachyarrhythmia, CHD, or channelopathy → high index of suspicion for cardiac cause

Section 7: Management of Specific Arrhythmias

Atrial Ectopy and SVT

• PACs require no treatment unless highly symptomatic; avoid caffeine, alcohol, stimulants, beta-agonists
• Acute SVT: vagal manoeuvres first; adenosine IV first-line pharmacological; beta-blockers (metoprolol/propranolol IV) if adenosine fails; verapamil IV last resort (caution: significant hypotension)
• Chronic SVT prevention: digoxin, metoprolol, propranolol (robust safety records); avoid atenolol
• WPW in pregnancy: flecainide or propafenone preferred (block accessory pathway); avoid AV nodal blockers (verapamil, diltiazem, digoxin, amiodarone — enhance accessory pathway conduction)
• Catheter ablation: curative option ideally pre-pregnancy; during pregnancy use zero-fluoroscopy technique after first trimester
• Tachycardia-induced cardiomyopathy: occurs with sustained focal AT; normalisation of EF with therapy common; beta-blockers first-line; ablation if refractory
• Amiodarone: last resort for hemodynamically significant refractory SVT

Atrial Fibrillation and Atrial Flutter

• AF is the most common sustained newly diagnosed arrhythmia in pregnancy
• DC cardioversion: first-line for AF/AFL with hemodynamic compromise
• Rate control (acceptable for asymptomatic): beta-blockers, digoxin, calcium channel blockers
• Rhythm control: elective cardioversion ± antiarrhythmic drugs; ibutilide (with IV magnesium pre-treatment) safe for acute conversion; oral flecainide bolus an option
• Anticoagulation: CHA₂DS₂-VASc score applies; DOACs contraindicated; LMWH or warfarin per mechanical valve protocol (Table 7); transition off VKA in peripartum period
• Up to two-thirds of women with AF/AFL without SHD may not need long-term medical therapy
• Catheter ablation: lower threshold for typical AFL ablation (simpler procedure); AF ablation during pregnancy generally deferred
• Amiodarone: reserved for refractory cases with SHD

Ventricular Arrhythmias

• Hemodynamically unstable VT: immediate DC cardioversion; same approach as non-pregnant
• PVCs with cardiomyopathy: beta-blockers first-line; verapamil for idiopathic outflow tract VT if needed
• Frequent PVCs causing cardiomyopathy: catheter ablation may be needed
• Idiopathic VT (RVOT, fascicular): beta-blockers or verapamil; ablation if refractory
• New VT in pregnancy: evaluate for underlying SHD, channelopathy, ACM

Section 8: Bradycardia and Heart Block

• Pacemaker implantation: follow same indications as non-pregnant; can be performed safely during pregnancy with minimal/zero fluoroscopy
• Congenital heart block (anti-Ro/SSA, anti-La/SSB antibody-associated): serial fetal monitoring; dexamethasone controversial; IVIG if immune-mediated
• Hemodynamically stable AV block with narrow QRS and acceptable rate: conservative management at delivery; pacemaker not mandated peripartum
• Sinus node dysfunction: beta-blockers/CCBs may worsen; temporary pacing available

Section 9: Cardiac Arrest in Pregnancy (ACLS)

• Management same as non-pregnant in first ~20 weeks (small uterus, no aortocaval compression)
• From ~20 weeks: manual left uterine displacement during CPR; alternatively left lateral tilt with wedge
• Standard hand position for chest compressions (no modification needed); standard energy for defibrillation
• Lead placement: avoid breast tissue; avoid fetal monitoring systems delaying maternal defibrillation
• IV access: above the diaphragm preferred; interosseous humerus if no central access
• Perimortem/resuscitative hysterotomy (C-section): if viable fetus and maternal arrest; initiate delivery within 5 minutes of arrest; perform wherever resuscitation is occurring (no operating room required); maternal survival often improves after uterine evacuation; do not transport patient for C-section
• Pharmacological management of arrest: same drugs as non-pregnant (no evidence for modification)

Section 10: Arrhythmogenic Structural Cardiac Substrates

• SHD: new arrhythmia in pregnancy may be first manifestation of undiagnosed SHD; echocardiogram mandatory
• CHD: 50% develop atrial tachyarrhythmia by young adulthood; ventricular arrhythmias leading cause of SCD (up to 100× higher than age-matched controls); rate control + rhythm control depending on substrate; anticoagulation for IART
• Valvular heart disease: mitral stenosis highest risk for AF (2.5% in ROPAC); tight mitral stenosis drives AF risk
• ACM: avoid exercise; risk of sustained VA; maintain appropriate medications; genetic counselling for offspring
• HCM: beta-blockers for rate/arrhythmia control; maintain preload; ICD per standard indications

Section 11: Fetal Arrhythmias (See concepts/Fetal-Arrhythmia)

Fetal Atrial Tachyarrhythmias

• Normal fetal HR: 110–160 bpm
• Fetal arrhythmias diagnosed in ~1% of all fetuses; up to 49% of referrals for fetal echo
• Intermittent (<50% of the time) SVT or AFL: monitoring only (no pharmacotherapy required)
• Incessant (>50% of the time) SVT or AFL with/without hydrops: pharmacological therapy required
• First-line for fetal SVT: flecainide (superior to digoxin and sotalol; advantage most marked when hydrops present) — based on meta-analysis of 10 studies, 537 patients
• First-line for fetal AFL: sotalol or digoxin (sotalol may have slight advantage for incessant flutter)
• Verapamil avoided for fetal SVT (unexpected fetal death reported; safer options available)
• Digoxin less effective when hydrops present (impaired transplacental transfer)
• Amiodarone: last resort for drug-refractory fetal SVT (converts 14/15 in one series)
• Direct intramuscular/intraperitoneal injection: reserved for refractory cases with hydrops
• Close-to-term fetus with incessant flutter or SVT with hydrops: delivery preferable to ongoing maternal pharmacotherapy

Fetal Ventricular Tachycardia

• Most fetal VT associated with IAS (especially LQTS)
• Non-IAS fetal VT causes: AV block, cardiac tumours, myocarditis, ventricular aneurysms, cardiomyopathy, accelerated idioventricular (usually benign)
• First-line: maternal IV magnesium + lidocaine (limit magnesium to <48 hours)
• Alternatives: oral propranolol, mexiletine
• Refractory: sotalol, flecainide, amiodarone — no single drug superior
• Myocarditis-associated VT: dexamethasone + IVIG (limited, conflicting data)

Fetal Bradycardia/Conduction Disorders

• Congenital complete heart block: associated with maternal anti-Ro/anti-La antibodies (neonatal lupus); high risk of hydrops and fetal death; multidisciplinary management
• Dexamethasone: may prevent progression from 2nd to 3rd degree; benefit for 3rd-degree block controversial
• Pacing (after delivery): required for symptomatic complete heart block in neonates

Section 12: Inherited Arrhythmia Syndromes (IAS)

• General: Genetic testing results predict severity, influence drug choice, assist fetal risk stratification; 5–10% of unexplained stillbirths may harbour IAS
• Pregnancies with IAS: 8× higher fetal stillbirth rate, 2× higher miscarriage rate (Cuneo et al., 148 pregnancies); maternal IAS more dangerous than paternal IAS
• Delivery planning essential: risk-stratified three-tier framework (Figure 19) for IAS labor management
• ICD implantation: follows standard indications regardless of pregnancy; safe with minimal radiation; pre-pregnancy implantation preferred

LQTS in Pregnancy

• Most common types: LQTS1 (KCNQ1), LQTS2 (KCNH2), LQTS3 (SCN5A) — account for 75–85% of fetal presentations
• Beta-blockers recommended throughout pregnancy and postpartum; nadolol preferred (long-acting, superior QTc control)
• LQTS2 is highest-risk subgroup in pregnancy and especially postpartum (Figure 20, Seth et al.)
• QTc >500 ms with LQTS2: consider ICD or wearable defibrillator in postpartum period
• Fetal echo: routine at 20–22 weeks if parent has LQTS; rhythm disorders more reliably diagnosed after 27 weeks
• Avoid QT-prolonging perioperative drugs (Table 6)
• Postpartum: continue beta-blockers ≥9 months; high-risk monitoring plan

Brugada Syndrome in Pregnancy

• Women generally at lower risk than men; pregnancy does not appear to increase arrhythmic risk (series of 104 women)
• General management same as non-pregnant (treat fever aggressively — fever precipitates VF in BrS; avoid contraindicated drugs at www.brugadadrugs.org)
• Risk prognostication in women remains challenging; spontaneous type 1 pattern and symptom status do not reliably predict events in women

CPVT in Pregnancy

• Beta-blockers mandatory throughout; add flecainide for recurrent syncope/VT
• Retrospective series (96 women, 228 pregnancies): no increased events during pregnancy or postpartum (but majority diagnosed after pregnancies)
• ICD for post–cardiac arrest: consider VT storm risk with each shock (may perpetuate adrenergic cascade)

Short QT Syndrome in Pregnancy

• Very limited data; general advice: manage as non-pregnant; hydroquinidine may be considered; ICD for high-risk patients

Limitations of the Document

• Limited RCT evidence in this population; evidence predominantly from registries, case series, and case reports
• Fetal arrhythmia data largely from non-randomised retrospective studies with small numbers
• Drug safety data in breastfeeding based on limited pharmacokinetic studies; <20% of new drug labels contain human lactation data
• Most IAS pregnancy data from retrospective single-centre series; miscarriage/stillbirth denominators uncertain

Key Concepts Mentioned

• concepts/Arrhythmia-in-Pregnancy — primary concept page for this source
• concepts/Fetal-Arrhythmia — comprehensive fetal arrhythmia management
• concepts/LQTS-Pregnancy-Management — LQTS-specific management during pregnancy
• concepts/Antiarrhythmic-Drugs — drug safety in pregnancy and lactation
• concepts/Cardio-Obstetrics — multidisciplinary team framework
• concepts/SVT-Management — SVT in pregnancy
• concepts/Torsades-de-Pointes — LQTS-triggered TdP in pregnancy
• concepts/Vasovagal-Syncope — most common syncope type in pregnancy
• concepts/Inappropriate-Sinus-Tachycardia — IST in pregnancy (8% triggered by pregnancy)
• concepts/Tachycardia-Induced-Cardiomyopathy — from sustained focal AT in pregnancy
• concepts/Left-Cardiac-Sympathetic-Denervation — for IAS in pregnancy (post-partum)
• concepts/Sudden-Cardiac-Death — IAS-related SCD risk

Key Entities Mentioned

• entities/Long-QT-Syndrome — highest-risk IAS in pregnancy
• entities/Brugada-Syndrome — pregnancy management
• entities/CPVT — pregnancy management
• entities/Short-QT-Syndrome — pregnancy (very limited data)
• entities/Atrial-Fibrillation — most common sustained arrhythmia in pregnancy
• entities/Atrial-Flutter — fetal AFL management
• entities/ICD — device management in pregnancy
• entities/Amiodarone — last resort in pregnancy; significant fetal toxicity
• entities/Flecainide — preferred for fetal SVT (especially with hydrops)
• entities/Peripartum-Cardiomyopathy — SHD context for arrhythmia management

Wiki Pages Updated

• Created: wiki/sources/arrhythmia-pregnancy-hrs-2023.md
• Created: wiki/concepts/Arrhythmia-in-Pregnancy.md
• Created: wiki/concepts/Fetal-Arrhythmia.md
• Updated: wiki/concepts/LQTS-Pregnancy-Management.md
• Updated: wiki/concepts/Cardio-Obstetrics.md
• Updated: wiki/sourceindex.md
• Updated: wiki/wikiindex.md