1. 🔍 Definition & Pathophysiology
Ebstein anomaly is a rare congenital cardiac defect characterized by downward (apical) displacement of the septal and posterior leaflets of the tricuspid valve into the right ventricle, resulting in “atrialization” of a portion of the RV and dilatation of the right atrium. Leaflets may be tethered or fenestrated, with an enlarged annulus and variable chordal anomalies. This displacement typically exceeds 8 mm/m² on echocardiographic assessment Pediatrics+13NCBI+13UCSF Health+13.
Consequences include:
- Severe tricuspid regurgitation
- Abnormal RV function and chamber geometry
- Enlarged RA and atrialized RV
- Frequent right-to-left shunts via ASD or PFO
- High incidence (25–65%) of accessory pathways/WPW, leading to arrhythmias WikipediaNCBI+1Wikipedia+1
2. 🌍 Epidemiology
- Incidence ~0.2–0.7 per 10,000 live births (~0.3–0.6% of congenital heart disease) NCBI.
- Gender prevalence is equal. Slightly higher incidence in Caucasians.
- Majority are sporadic; familial recurrence: ~6% from mothers, ~1% from fathers AHA Journals.
- Associated with chromosomal anomalies (15q duplications, MYH7, NKX2‑5) NCBI.
3. 🚼 Etiology & Risk Factors
- Most cases idiopathic.
- Historical lithium or benzodiazepine exposure in pregnancy remains controversial – newer studies suggest underlying maternal psychiatric illness may be the true correlate SAGE Journals+3Cambridge University Press & Assessment+3Psychiatry Online+3.
- Genetic mutations in cardiac developmental genes also implicated ScienceDirect+15NCBI+15Penn Medicine+15.
4. 🩺 Clinical Presentation
- Highly variable—from asymptomatic adults to neonates with cyanosis, heart failure, or shock NCBI.
- Neonates: may present prenatally or shortly after birth with cyanosis and perinatal mortality ~45% in severe cases .
- Adults: present with exertional dyspnea, palpitations, fatigue, cyanosis, edema, or syncope NCBI.
- Arrhythmias are common; risk of sudden cardiac death exists .
5. 🧪 Diagnostic Evaluation
- ECG: tall “Himalayan” P waves (RA enlargement), right-axis deviation, WPW features, first-degree AV block, RBBB pattern Wikipedia.
- Echocardiography: first-line—quantifies tricuspid displacement (>8 mm/m²), assesses regurgitation, RV function, shunts PMC+4NCBI+4Wikipedia+4.
- Cardiac MRI: for detailed anatomy, RV volumes, and pre-surgical planning.
- Chest X-ray: RA enlargement, cardiomegaly.
- Holter/EP studies: evaluate arrhythmias and plan intervention.
6. 📈 Natural History & Prognosis
- Prognosis correlates with the severity of leaflet displacement, RV dysfunction, and tricuspid regurgitation .
- Celermajer index (RA + atrialized RV area vs. functional cardiac chambers) predicts mortality: Grade I (<0.5) 0%, Grade III higher NCBI+1Cambridge University Press & Assessment+1.
- Left untreated: 1-year survival ~90%, falls to ~40% by 20 years .
- Surgical outcomes improved: post-cone repair survival ~98% at 1 year, ~76% at 20 years; reoperation ~2% at 6 years NCBI.
7. 🏥 Management
A. Surveillance
- All patients require lifelong cardiology care, preferably by ACHD specialists.
- Serial echocardiography (annually or per symptom progression) UpToDate.
B. Medical Therapy
- Congestive symptoms: diuretics, ACE inhibitors/β-blockers as needed.
- Arrhythmias: accessory pathway–mediated SVT → procainamide or class Ic agents; AV nodal blockers contraindicated .
- WPW/arrhythmias: early catheter ablation or surgical cryoablation, especially before valve repair NCBI.
- Anticoagulation: for AF or paradoxical embolism risk NCBI.
- Endocarditis prophylaxis: for uncorrected anomalies or post-valve surgery .
C. Surgical Indications & Techniques
Per 2025 AATS consensus aats.org+2PubMed+2J Thorac Cardiovasc Surg+2, refer for surgery when:
- Symptomatic NYHA II–IV, RV dysfunction, cyanosis, cardiomegaly (CTR >65%).
- Severe tricuspid regurgitation, large ASD with cyanosis, arrhythmias failing medical therapy.
Preferred surgical strategy:
- Cone reconstruction of the tricuspid valve—standard in skilled centers, with excellent long-term outcomes NCBI+1Wikipedia+1ScienceDirect+1aats.org+1.
- Neonatal management (AATS 2024): emergent Starnes procedure or modified biventricular repair depending on clinical status PubMed+2aats.org+2PubMed+2.
- Valve replacement reserved for non-repairable valves.
8. 💡 Key Clinical Pearls
- Presentation and progression vary greatly; clinical judgment guided by anatomy, function, and symptoms.
- Arrhythmia management is essential to reduce sudden cardiac death risk.
- Early valve repair before irreversible RV dysfunction yields better outcomes.
- Multidisciplinary care (ACHD cardiology, electrophysiology, cardiothoracic surgery) is critical.
🧭 Summary Table
| Feature | Highlights |
|---|---|
| Diagnosis | Echocardiogram (primary), ECG, CMRI, Holter, EP studies |
| Monitoring | Lifelong surveillance; annual echo unless mild |
| Medical Management | Diuretics, anti-arrhythmics, ablation, anticoagulation |
| Surgery | Cone repair, neonatal procedures (Starnes), valve replacement when needed |
| Prognosis | Variable; improved with early repair and arrhythmia control |