FCPS Paediatrics TOACS · Ebstein Anomaly of the Tricuspid Valve
💙 15-year-old with palpitations, cyanosis, ECG: RBBB, tall P waves, WPW – Apical displacement of tricuspid valve, ASD, Cone repair, Starnes procedure
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⚕️ OBSERVED STATION · CPSP FORMAT · 8 MINUTES · SEPARATE TABS · CLINICAL SCENARIO
📖 Problem-oriented Clinical Scenario – Ebstein Anomaly
👶🏻 Clinical Scenario (read aloud – 2 min):
A 15-year-old girl presents to the cardiology clinic with a history of palpitations and occasional lightheadedness over the past year. She reports that her heart "races" suddenly, often when she is resting, and the episodes last 5-10 minutes. She has also noticed that her fingernails and lips appear bluish during exercise, but this resolves with rest. She has a history of mild exercise intolerance and has had one episode of near-syncope during a school sports activity. There is no known heart disease in the family.
Examination: Vital signs: HR 80 bpm (irregular), BP 110/65 mm Hg, RR 18/min, SpO2 88% on room air (desaturates to 82% with exercise). Cardiovascular examination reveals a widely split S1 (due to delayed tricuspid closure), a holosystolic murmur at the left lower sternal border that increases with inspiration (Carvallo sign), and a soft ejection murmur at the left upper sternal border. There is mild cyanosis and clubbing of the fingers. The liver is not palpable.
ECG (obtained in clinic):
Task for the candidate: You are the pediatric cardiologist. Evaluate this patient, interpret the ECG (RBBB, tall P waves, WPW), discuss the pathophysiology of Ebstein anomaly (apical displacement of tricuspid valve, atrialized RV, TR, ASD), formulate a management plan (medical therapy, ablation for WPW, surgical cone repair), and provide counseling to the patient and family about prognosis and follow-up.
A 15-year-old girl presents to the cardiology clinic with a history of palpitations and occasional lightheadedness over the past year. She reports that her heart "races" suddenly, often when she is resting, and the episodes last 5-10 minutes. She has also noticed that her fingernails and lips appear bluish during exercise, but this resolves with rest. She has a history of mild exercise intolerance and has had one episode of near-syncope during a school sports activity. There is no known heart disease in the family.
Examination: Vital signs: HR 80 bpm (irregular), BP 110/65 mm Hg, RR 18/min, SpO2 88% on room air (desaturates to 82% with exercise). Cardiovascular examination reveals a widely split S1 (due to delayed tricuspid closure), a holosystolic murmur at the left lower sternal border that increases with inspiration (Carvallo sign), and a soft ejection murmur at the left upper sternal border. There is mild cyanosis and clubbing of the fingers. The liver is not palpable.
ECG (obtained in clinic):
Figure: ECG shows right bundle branch block (RBBB), tall peaked P waves (right atrial enlargement), and short PR interval with delta wave (WPW pattern) – classic findings in Ebstein anomaly.
💡 Examiner instruction (interactive): This is a case of Ebstein Anomaly – a rare congenital heart defect characterized by apical displacement of the tricuspid septal and posterior leaflets, leading to an atrialized right ventricle, tricuspid regurgitation, and right atrial enlargement. The candidate must recognize the classic ECG findings: right bundle branch block (RBBB), tall peaked P waves (right atrial enlargement), and WPW syndrome (short PR, delta wave) in ~25% of cases. The candidate should also understand the pathophysiology (right-to-left shunt through ASD/PFO causing cyanosis), the association with WPW, and the management options (observation for mild cases, radiofrequency ablation for WPW, cone repair for significant TR, and Starnes procedure for severe neonatal form). The candidate should discuss the Carvallo sign (TR murmur increases with inspiration) and the classic chest X-ray finding (massive cardiomegaly).
🔍 Examiner Questions (interactive) – Click to reveal model answers
❓ Q1 (Examiner): “Describe the ECG findings in this patient. What are the classic ECG features of Ebstein anomaly?”
✅ Candidate's answer:
• Classic ECG findings in Ebstein anomaly:
1️⃣ Right bundle branch block (RBBB): rsR' pattern in V1-V2 with wide QRS (≥0.12 sec). Present in most patients.
2️⃣ Tall peaked P waves: Right atrial enlargement (P pulmonale) – tall P waves (>2.5 mm) in leads II, III, aVF.
3️⃣ WPW syndrome (in 25%): Short PR interval (<0.08 sec in children), delta wave (slurred upstroke of QRS), wide QRS.
4️⃣ First-degree AV block: Prolonged PR interval – may be present.
5️⃣ Low voltage: May be seen in some cases.
- Differential diagnosis: RBBB with tall P waves can also be seen in other causes of right atrial enlargement (e.g., pulmonary stenosis, pulmonary hypertension), but the combination with WPW is highly suggestive of Ebstein anomaly.
• Significance: The ECG is often abnormal in Ebstein anomaly and can provide important clues to the diagnosis.
• Classic ECG findings in Ebstein anomaly:
1️⃣ Right bundle branch block (RBBB): rsR' pattern in V1-V2 with wide QRS (≥0.12 sec). Present in most patients.
2️⃣ Tall peaked P waves: Right atrial enlargement (P pulmonale) – tall P waves (>2.5 mm) in leads II, III, aVF.
3️⃣ WPW syndrome (in 25%): Short PR interval (<0.08 sec in children), delta wave (slurred upstroke of QRS), wide QRS.
4️⃣ First-degree AV block: Prolonged PR interval – may be present.
5️⃣ Low voltage: May be seen in some cases.
- Differential diagnosis: RBBB with tall P waves can also be seen in other causes of right atrial enlargement (e.g., pulmonary stenosis, pulmonary hypertension), but the combination with WPW is highly suggestive of Ebstein anomaly.
• Significance: The ECG is often abnormal in Ebstein anomaly and can provide important clues to the diagnosis.
❓ Q2 (Examiner): “Explain the pathophysiology of Ebstein anomaly. What is meant by 'atrialized right ventricle'?”
✅ Candidate's answer:
• Ebstein anomaly: Congenital malformation of the tricuspid valve characterized by apical displacement of the septal and posterior leaflets into the right ventricle.
• Displacement index: ≥8 mm/m² (measured from the annulus).
• Atrialized right ventricle: The portion of the RV proximal to the displaced valve becomes thin-walled, dysfunctional, and electrically silent. It functions as part of the right atrium, causing massive RA enlargement and TR.
• Consequences:
- Tricuspid regurgitation (TR): Incompetent valve → RA enlargement.
- Right-to-left shunt: If ASD/PFO is present, increased RA pressure causes cyanosis.
- Reduced RV function: The remaining RV (functional RV) may be small and dysfunctional.
- WPW: Accessory pathways (right-sided) in 25% of patients.
- Pulmonary blood flow: May be reduced due to functional pulmonary atresia (severe neonatal form) or normal.
• Ebstein anomaly: Congenital malformation of the tricuspid valve characterized by apical displacement of the septal and posterior leaflets into the right ventricle.
• Displacement index: ≥8 mm/m² (measured from the annulus).
• Atrialized right ventricle: The portion of the RV proximal to the displaced valve becomes thin-walled, dysfunctional, and electrically silent. It functions as part of the right atrium, causing massive RA enlargement and TR.
• Consequences:
- Tricuspid regurgitation (TR): Incompetent valve → RA enlargement.
- Right-to-left shunt: If ASD/PFO is present, increased RA pressure causes cyanosis.
- Reduced RV function: The remaining RV (functional RV) may be small and dysfunctional.
- WPW: Accessory pathways (right-sided) in 25% of patients.
- Pulmonary blood flow: May be reduced due to functional pulmonary atresia (severe neonatal form) or normal.
❓ Q3 (Examiner): “What are the associated cardiac defects in Ebstein anomaly? What is the incidence of WPW?”
✅ Candidate's answer:
• Associated defects in Ebstein anomaly:
1️⃣ ASD or PFO: Present in 80-90% of patients – allows right-to-left shunting → cyanosis.
2️⃣ Wolff-Parkinson-White (WPW) syndrome: Occurs in 25% of patients – accessory pathways (right-sided).
3️⃣ Pulmonary stenosis or atresia: Functional (due to RV dysfunction) or anatomic.
4️⃣ VSD: Less common.
5️⃣ Mitral valve prolapse: May be seen.
• WPW incidence: 25% – this is the most common arrhythmia associated with Ebstein anomaly. The accessory pathways are often right-sided and multiple.
• Clinical significance: WPW increases the risk of SVT and atrial fibrillation, which can be life-threatening if rapid conduction occurs.
• Associated defects in Ebstein anomaly:
1️⃣ ASD or PFO: Present in 80-90% of patients – allows right-to-left shunting → cyanosis.
2️⃣ Wolff-Parkinson-White (WPW) syndrome: Occurs in 25% of patients – accessory pathways (right-sided).
3️⃣ Pulmonary stenosis or atresia: Functional (due to RV dysfunction) or anatomic.
4️⃣ VSD: Less common.
5️⃣ Mitral valve prolapse: May be seen.
• WPW incidence: 25% – this is the most common arrhythmia associated with Ebstein anomaly. The accessory pathways are often right-sided and multiple.
• Clinical significance: WPW increases the risk of SVT and atrial fibrillation, which can be life-threatening if rapid conduction occurs.
❓ Q4 (Examiner): “This patient has a holosystolic murmur at the LLSB that increases with inspiration. What is this sign and what does it indicate?”
✅ Candidate's answer:
• Carvallo sign: The murmur of tricuspid regurgitation (holosystolic, best heard at the left lower sternal border) increases in intensity with inspiration.
• Mechanism: Inspiration increases venous return to the right heart → increased right ventricular volume → increased tricuspid regurgitation → louder murmur.
• Significance:
- Helps distinguish tricuspid regurgitation (increases with inspiration) from mitral regurgitation (does not change or decreases with inspiration).
- In Ebstein anomaly, TR is a hallmark feature, and the Carvallo sign is often present.
• Other murmurs in Ebstein:
- Widely split S1 – due to delayed tricuspid closure (tricuspid valve clicks).
- Systolic ejection murmur at LUSB – due to increased flow across the pulmonary valve (if pulmonary flow is increased).
- Diastolic murmur – may be present if significant TR.
• Carvallo sign: The murmur of tricuspid regurgitation (holosystolic, best heard at the left lower sternal border) increases in intensity with inspiration.
• Mechanism: Inspiration increases venous return to the right heart → increased right ventricular volume → increased tricuspid regurgitation → louder murmur.
• Significance:
- Helps distinguish tricuspid regurgitation (increases with inspiration) from mitral regurgitation (does not change or decreases with inspiration).
- In Ebstein anomaly, TR is a hallmark feature, and the Carvallo sign is often present.
• Other murmurs in Ebstein:
- Widely split S1 – due to delayed tricuspid closure (tricuspid valve clicks).
- Systolic ejection murmur at LUSB – due to increased flow across the pulmonary valve (if pulmonary flow is increased).
- Diastolic murmur – may be present if significant TR.
❓ Q5 (Examiner): “What is the classic chest X-ray finding in Ebstein anomaly? Why does it occur?”
✅ Candidate's answer:
• Classic chest X-ray finding: Massive cardiomegaly – often described as a "box-shaped" or "water bottle" heart.
• Mechanism:
- Massive right atrial enlargement: Due to the atrialized right ventricle and severe tricuspid regurgitation.
- RA enlargement: The RA becomes massively dilated, pushing the cardiac silhouette to the right and left.
- Decreased pulmonary vascularity: If pulmonary blood flow is reduced (functional pulmonary atresia).
- Normal or decreased lung fields: The heart is so large that it occupies most of the chest.
• Differential diagnosis: Massive cardiomegaly can also be seen in pericardial effusion, severe TR from other causes, and cardiomyopathy. However, in a cyanotic patient with these ECG findings, Ebstein anomaly is the most likely diagnosis.
• Classic chest X-ray finding: Massive cardiomegaly – often described as a "box-shaped" or "water bottle" heart.
• Mechanism:
- Massive right atrial enlargement: Due to the atrialized right ventricle and severe tricuspid regurgitation.
- RA enlargement: The RA becomes massively dilated, pushing the cardiac silhouette to the right and left.
- Decreased pulmonary vascularity: If pulmonary blood flow is reduced (functional pulmonary atresia).
- Normal or decreased lung fields: The heart is so large that it occupies most of the chest.
• Differential diagnosis: Massive cardiomegaly can also be seen in pericardial effusion, severe TR from other causes, and cardiomyopathy. However, in a cyanotic patient with these ECG findings, Ebstein anomaly is the most likely diagnosis.
❓ Q6 (Examiner): “This patient has WPW on ECG. What is the management of WPW in Ebstein anomaly?”
✅ Candidate's answer:
• Management of WPW in Ebstein anomaly:
1️⃣ Electrophysiology study (EPS) and radiofrequency ablation: This is the treatment of choice for symptomatic patients with WPW (palpitations, SVT, syncope). Ablation of the accessory pathway is curative and eliminates the risk of SVT and atrial fibrillation with rapid conduction.
2️⃣ If ablation is not feasible or refused:
- Antiarrhythmic medications: Flecainide, propafenone, or sotalol – but ablation is preferred.
- Avoid digoxin and verapamil: These drugs can accelerate conduction over the accessory pathway during atrial fibrillation, leading to VF.
3️⃣ Asymptomatic WPW: If no symptoms and no high-risk features (short accessory pathway refractory period), observation may be considered. However, many experts recommend ablation in Ebstein anomaly because of the high risk of SVT and atrial fibrillation.
4️⃣ Risk of sudden death: WPW + atrial fibrillation can be life-threatening. Ablation is often recommended even in asymptomatic patients to prevent sudden death.
• Management of WPW in Ebstein anomaly:
1️⃣ Electrophysiology study (EPS) and radiofrequency ablation: This is the treatment of choice for symptomatic patients with WPW (palpitations, SVT, syncope). Ablation of the accessory pathway is curative and eliminates the risk of SVT and atrial fibrillation with rapid conduction.
2️⃣ If ablation is not feasible or refused:
- Antiarrhythmic medications: Flecainide, propafenone, or sotalol – but ablation is preferred.
- Avoid digoxin and verapamil: These drugs can accelerate conduction over the accessory pathway during atrial fibrillation, leading to VF.
3️⃣ Asymptomatic WPW: If no symptoms and no high-risk features (short accessory pathway refractory period), observation may be considered. However, many experts recommend ablation in Ebstein anomaly because of the high risk of SVT and atrial fibrillation.
4️⃣ Risk of sudden death: WPW + atrial fibrillation can be life-threatening. Ablation is often recommended even in asymptomatic patients to prevent sudden death.
❓ Q7 (Examiner): “What is the cone repair (Da Silva technique) for Ebstein anomaly? When is it performed?”
✅ Candidate's answer:
• Cone repair (Da Silva technique):
- A surgical technique for tricuspid valve repair in Ebstein anomaly.
- Procedure:
1️⃣ Detach the tricuspid valve leaflets from the annulus.
2️⃣ Rotate the leaflets 90-180 degrees to create a cone-shaped valve.
3️⃣ Reattach the leaflet tissue to the true annulus.
4️⃣ Close the ASD/PFO (if present).
5️⃣ Plication of the atrialized RV may be performed.
- Advantages: Excellent results, avoids valve replacement, improves RV function.
• When is it performed?
- Indications for surgery:
- Severe TR with RV dilation or dysfunction.
- Symptoms: Heart failure, cyanosis, exercise intolerance, arrhythmias.
- Paradoxical embolism.
- Progressive RV enlargement on echo/MRI.
- Timing: Usually performed in older children, adolescents, or adults (>3-5 years). For neonates, cone repair is often not feasible due to the severity of the lesion and the small size; the Starnes procedure is used instead.
• Cone repair (Da Silva technique):
- A surgical technique for tricuspid valve repair in Ebstein anomaly.
- Procedure:
1️⃣ Detach the tricuspid valve leaflets from the annulus.
2️⃣ Rotate the leaflets 90-180 degrees to create a cone-shaped valve.
3️⃣ Reattach the leaflet tissue to the true annulus.
4️⃣ Close the ASD/PFO (if present).
5️⃣ Plication of the atrialized RV may be performed.
- Advantages: Excellent results, avoids valve replacement, improves RV function.
• When is it performed?
- Indications for surgery:
- Severe TR with RV dilation or dysfunction.
- Symptoms: Heart failure, cyanosis, exercise intolerance, arrhythmias.
- Paradoxical embolism.
- Progressive RV enlargement on echo/MRI.
- Timing: Usually performed in older children, adolescents, or adults (>3-5 years). For neonates, cone repair is often not feasible due to the severity of the lesion and the small size; the Starnes procedure is used instead.
❓ Q8 (Examiner): “What is the Starnes procedure? When is it indicated?”
✅ Candidate's answer:
• Starnes procedure:
- A surgical procedure for critically ill neonates with severe Ebstein anomaly.
- Procedure:
1️⃣ Closure of the tricuspid valve orifice: Prevents severe TR and right-to-left shunting.
2️⃣ BT shunt (Blalock-Taussig): Provides pulmonary blood flow.
3️⃣ ASD creation: Allows decompression of the right heart.
4️⃣ Results in single ventricle physiology: The patient becomes a Fontan candidate.
- Indications:
- Severe neonatal Ebstein anomaly with functional pulmonary atresia.
- Massive cardiomegaly, severe cyanosis, and heart failure in the newborn period.
- Patients who are not candidates for cone repair due to the severity of the disease and small size.
- Outcome: High-risk procedure (mortality ~30-50%) but life-saving. The patient will eventually require a Fontan procedure.
• Starnes procedure:
- A surgical procedure for critically ill neonates with severe Ebstein anomaly.
- Procedure:
1️⃣ Closure of the tricuspid valve orifice: Prevents severe TR and right-to-left shunting.
2️⃣ BT shunt (Blalock-Taussig): Provides pulmonary blood flow.
3️⃣ ASD creation: Allows decompression of the right heart.
4️⃣ Results in single ventricle physiology: The patient becomes a Fontan candidate.
- Indications:
- Severe neonatal Ebstein anomaly with functional pulmonary atresia.
- Massive cardiomegaly, severe cyanosis, and heart failure in the newborn period.
- Patients who are not candidates for cone repair due to the severity of the disease and small size.
- Outcome: High-risk procedure (mortality ~30-50%) but life-saving. The patient will eventually require a Fontan procedure.
❓ Q9 (Examiner): “A newborn presents with severe cyanosis and massive cardiomegaly. What is the initial management?”
✅ Candidate's answer:
• Initial management of neonatal Ebstein anomaly:
1️⃣ PGE1 (Prostaglandin E1): 0.05-0.1 mcg/kg/min IV to maintain ductal patency. This is essential if there is functional pulmonary atresia (pulmonary blood flow is duct-dependent).
2️⃣ Supportive care: Ventilatory support, correction of acidosis, and treatment of heart failure if present.
3️⃣ Echocardiogram: To confirm the diagnosis, assess TR severity, RV function, and pulmonary valve (functional vs anatomic atresia).
4️⃣ Starnes procedure: If the infant is critically ill (severe cyanosis, massive cardiomegaly, heart failure), the Starnes procedure is indicated. This is the salvage operation for severe neonatal Ebstein.
5️⃣ If the infant is stable: May be managed medically (PGE1 weaned, watchful waiting) and cone repair deferred to later childhood.
6️⃣ Prognosis: Neonatal Ebstein has a high mortality (up to 50%) if untreated. Early intervention is crucial.
• Initial management of neonatal Ebstein anomaly:
1️⃣ PGE1 (Prostaglandin E1): 0.05-0.1 mcg/kg/min IV to maintain ductal patency. This is essential if there is functional pulmonary atresia (pulmonary blood flow is duct-dependent).
2️⃣ Supportive care: Ventilatory support, correction of acidosis, and treatment of heart failure if present.
3️⃣ Echocardiogram: To confirm the diagnosis, assess TR severity, RV function, and pulmonary valve (functional vs anatomic atresia).
4️⃣ Starnes procedure: If the infant is critically ill (severe cyanosis, massive cardiomegaly, heart failure), the Starnes procedure is indicated. This is the salvage operation for severe neonatal Ebstein.
5️⃣ If the infant is stable: May be managed medically (PGE1 weaned, watchful waiting) and cone repair deferred to later childhood.
6️⃣ Prognosis: Neonatal Ebstein has a high mortality (up to 50%) if untreated. Early intervention is crucial.
❓ Q10 (Examiner): “What are the indications for tricuspid valve surgery in Ebstein anomaly?”
✅ Candidate's answer:
• Indications for surgery (cone repair or tricuspid valve replacement):
1️⃣ Severe TR with RV dilation or dysfunction (RV end-diastolic volume index >150 mL/m²).
2️⃣ Symptoms: Heart failure (dyspnea, fatigue, exercise intolerance), cyanosis (SpO2 <90%), or arrhythmias refractory to medical therapy.
3️⃣ Paradoxical embolism – stroke or TIA due to right-to-left shunting through ASD/PFO.
4️⃣ Progressive RV enlargement on echocardiography or MRI.
5️⃣ Severe tricuspid regurgitation with significant right heart failure (hepatomegaly, ascites).
6️⃣ Atrial arrhythmias (atrial flutter, atrial fibrillation) – may require concomitant maze procedure.
7️⃣ WPW with symptomatic SVT – ablation is first-line, but surgery may be needed if ablation fails.
• Timing: Surgery is usually performed in older children/adolescents. Neonates are generally not candidates for cone repair (Starnes procedure is used in severe cases).
• Indications for surgery (cone repair or tricuspid valve replacement):
1️⃣ Severe TR with RV dilation or dysfunction (RV end-diastolic volume index >150 mL/m²).
2️⃣ Symptoms: Heart failure (dyspnea, fatigue, exercise intolerance), cyanosis (SpO2 <90%), or arrhythmias refractory to medical therapy.
3️⃣ Paradoxical embolism – stroke or TIA due to right-to-left shunting through ASD/PFO.
4️⃣ Progressive RV enlargement on echocardiography or MRI.
5️⃣ Severe tricuspid regurgitation with significant right heart failure (hepatomegaly, ascites).
6️⃣ Atrial arrhythmias (atrial flutter, atrial fibrillation) – may require concomitant maze procedure.
7️⃣ WPW with symptomatic SVT – ablation is first-line, but surgery may be needed if ablation fails.
• Timing: Surgery is usually performed in older children/adolescents. Neonates are generally not candidates for cone repair (Starnes procedure is used in severe cases).
❓ Q11 (Examiner): “Should the ASD be closed in Ebstein anomaly? What are the risks and benefits?”
✅ Candidate's answer:
• ASD in Ebstein anomaly: Present in 80-90% of patients. Allows right-to-left shunting → cyanosis.
• Indications for ASD closure:
- Usually closed during tricuspid valve surgery (cone repair or valve replacement).
- If paradoxical embolism occurs – closure is indicated.
- If cyanosis is significant and surgery is being performed.
• Risks of ASD closure:
- Right heart failure: If the ASD is a "pop-off" valve for the right heart, closing it may increase right-sided pressures and worsen heart failure.
- Increased cyanosis: Paradoxically, if the ASD is closed, the left-to-right shunt may decrease, but the right-to-left shunt may become worse if RV function is poor.
• Recommendation: ASD closure is generally performed only if the tricuspid valve is repaired and the right heart can handle the volume. In patients with severe RV dysfunction, ASD closure may be delayed or not performed.
• ASD in Ebstein anomaly: Present in 80-90% of patients. Allows right-to-left shunting → cyanosis.
• Indications for ASD closure:
- Usually closed during tricuspid valve surgery (cone repair or valve replacement).
- If paradoxical embolism occurs – closure is indicated.
- If cyanosis is significant and surgery is being performed.
• Risks of ASD closure:
- Right heart failure: If the ASD is a "pop-off" valve for the right heart, closing it may increase right-sided pressures and worsen heart failure.
- Increased cyanosis: Paradoxically, if the ASD is closed, the left-to-right shunt may decrease, but the right-to-left shunt may become worse if RV function is poor.
• Recommendation: ASD closure is generally performed only if the tricuspid valve is repaired and the right heart can handle the volume. In patients with severe RV dysfunction, ASD closure may be delayed or not performed.
❓ Q12 (Examiner): “What is the long-term prognosis for a patient with Ebstein anomaly?”
✅ Candidate's answer:
• Prognosis depends on:
- Severity of the anomaly: Mild forms have an excellent prognosis with normal life expectancy. Severe neonatal forms have a guarded prognosis.
- Presence of symptoms: Cyanosis, heart failure, and arrhythmias worsen prognosis.
- RV function: Preserved RV function is associated with better outcomes.
- Arrhythmias: WPW and atrial arrhythmias increase morbidity and mortality.
• With surgical repair:
- Cone repair: Excellent results – most patients have good valve function and improved symptoms.
- Starnes procedure: High mortality (30-50%) but life-saving.
• Long-term follow-up: Lifelong cardiology follow-up. Annual echocardiograms to monitor TR severity, RV function, and valve repair integrity. Monitor for arrhythmias (WPW, atrial flutter).
• Pregnancy: Patients with repaired Ebstein and good RV function can often tolerate pregnancy, but it is high-risk and requires multidisciplinary care.
• Prognosis depends on:
- Severity of the anomaly: Mild forms have an excellent prognosis with normal life expectancy. Severe neonatal forms have a guarded prognosis.
- Presence of symptoms: Cyanosis, heart failure, and arrhythmias worsen prognosis.
- RV function: Preserved RV function is associated with better outcomes.
- Arrhythmias: WPW and atrial arrhythmias increase morbidity and mortality.
• With surgical repair:
- Cone repair: Excellent results – most patients have good valve function and improved symptoms.
- Starnes procedure: High mortality (30-50%) but life-saving.
• Long-term follow-up: Lifelong cardiology follow-up. Annual echocardiograms to monitor TR severity, RV function, and valve repair integrity. Monitor for arrhythmias (WPW, atrial flutter).
• Pregnancy: Patients with repaired Ebstein and good RV function can often tolerate pregnancy, but it is high-risk and requires multidisciplinary care.
❓ Q13 (Examiner): “Is Ebstein anomaly associated with any genetic syndromes?”
✅ Candidate's answer:
• Genetics of Ebstein anomaly:
- Most cases are sporadic (no known genetic cause).
- Familial cases are rare but have been reported.
- Associated with:
- NKX2.5 mutations: Associated with ASD and Ebstein-like anomalies.
- Maternal lithium exposure: Historical association (now less clear).
- Noonan syndrome – occasionally associated with Ebstein.
- Congenital heart disease syndromes – rarely.
• Genetic counseling: For families with affected individuals, genetic testing (NKX2.5, other CHD genes) may be considered, but routine testing is not typically recommended. Recurrence risk is low (2-3%) for sporadic cases.
• Genetics of Ebstein anomaly:
- Most cases are sporadic (no known genetic cause).
- Familial cases are rare but have been reported.
- Associated with:
- NKX2.5 mutations: Associated with ASD and Ebstein-like anomalies.
- Maternal lithium exposure: Historical association (now less clear).
- Noonan syndrome – occasionally associated with Ebstein.
- Congenital heart disease syndromes – rarely.
• Genetic counseling: For families with affected individuals, genetic testing (NKX2.5, other CHD genes) may be considered, but routine testing is not typically recommended. Recurrence risk is low (2-3%) for sporadic cases.
❓ Q14 (Examiner): “The patient and her family are anxious about the diagnosis. How will you counsel them?”
✅ Candidate's structured answer:
• “You have a condition called Ebstein anomaly – a rare congenital heart defect where the tricuspid valve (the valve between the right upper and lower chambers) is abnormally positioned lower than normal. This causes the valve to leak (tricuspid regurgitation) and can lead to enlargement of the right heart.”
• “The ECG shows some characteristic changes – a pattern called right bundle branch block, tall P waves (showing that the right atrium is enlarged), and a fast-rhythm pathway called WPW. The WPW can cause palpitations, which is why you sometimes feel your heart racing.”
• “The good news is that we have excellent treatments. If your symptoms are mild, we can observe you and treat the palpitations with a procedure called catheter ablation – where we cauterize the extra pathway in the heart. If the valve leakage is significant, we can repair the valve using a surgery called the cone repair – which has excellent results.”
• “You will need lifelong follow-up with a cardiologist, but most patients with Ebstein anomaly live long, active lives. We will monitor your heart with annual echocardiograms.”
• “We will also discuss pregnancy risks in the future, if you choose to have children – we can plan that together with a team of specialists.”
• “You have a condition called Ebstein anomaly – a rare congenital heart defect where the tricuspid valve (the valve between the right upper and lower chambers) is abnormally positioned lower than normal. This causes the valve to leak (tricuspid regurgitation) and can lead to enlargement of the right heart.”
• “The ECG shows some characteristic changes – a pattern called right bundle branch block, tall P waves (showing that the right atrium is enlarged), and a fast-rhythm pathway called WPW. The WPW can cause palpitations, which is why you sometimes feel your heart racing.”
• “The good news is that we have excellent treatments. If your symptoms are mild, we can observe you and treat the palpitations with a procedure called catheter ablation – where we cauterize the extra pathway in the heart. If the valve leakage is significant, we can repair the valve using a surgery called the cone repair – which has excellent results.”
• “You will need lifelong follow-up with a cardiologist, but most patients with Ebstein anomaly live long, active lives. We will monitor your heart with annual echocardiograms.”
• “We will also discuss pregnancy risks in the future, if you choose to have children – we can plan that together with a team of specialists.”
🗣️ Examiner's probing / high-yield points (Ebstein Anomaly):
• "What are the classic ECG findings in Ebstein anomaly?" → RBBB, tall P waves (RA enlargement), WPW (25%).
• "What is the Carvallo sign?" → TR murmur increases with inspiration.
• "What is the chest X-ray finding?" → Massive cardiomegaly (box-shaped heart).
• "What is the treatment for WPW in Ebstein?" → Radiofrequency ablation.
• "What is the cone repair?" → Tricuspid valve repair (Da Silva technique).
• "What is the Starnes procedure?" → Tricuspid closure + BT shunt for severe neonatal Ebstein.
• "What is the atrialized RV?" → Thin-walled, dysfunctional portion of RV proximal to displaced valve.
• "What is the incidence of WPW in Ebstein?" → 25%.
• "What is the most common associated defect?" → ASD/PFO (80-90%).
• "What is the Carvallo sign?" → Increases with inspiration (TR).
• "What are the classic ECG findings in Ebstein anomaly?" → RBBB, tall P waves (RA enlargement), WPW (25%).
• "What is the Carvallo sign?" → TR murmur increases with inspiration.
• "What is the chest X-ray finding?" → Massive cardiomegaly (box-shaped heart).
• "What is the treatment for WPW in Ebstein?" → Radiofrequency ablation.
• "What is the cone repair?" → Tricuspid valve repair (Da Silva technique).
• "What is the Starnes procedure?" → Tricuspid closure + BT shunt for severe neonatal Ebstein.
• "What is the atrialized RV?" → Thin-walled, dysfunctional portion of RV proximal to displaced valve.
• "What is the incidence of WPW in Ebstein?" → 25%.
• "What is the most common associated defect?" → ASD/PFO (80-90%).
• "What is the Carvallo sign?" → Increases with inspiration (TR).
📘 Ebstein Anomaly – Core Revision for TOACS
💙 Definition
Apical displacement of tricuspid septal and posterior leaflets into RV (≥8 mm/m²) → atrialized RV, TR, RA enlargement. <1% of CHD.
Apical displacement of tricuspid septal and posterior leaflets into RV (≥8 mm/m²) → atrialized RV, TR, RA enlargement. <1% of CHD.
📊 ECG Findings
RBBB, tall P waves (RA enlargement), WPW (25% – short PR, delta wave).
RBBB, tall P waves (RA enlargement), WPW (25% – short PR, delta wave).
📸 CXR
Massive cardiomegaly (box-shaped or water bottle heart) due to RA enlargement.
Massive cardiomegaly (box-shaped or water bottle heart) due to RA enlargement.
🔍 Associated Defects
ASD/PFO (80-90%), WPW (25%), pulmonary stenosis/atresia, VSD.
ASD/PFO (80-90%), WPW (25%), pulmonary stenosis/atresia, VSD.
💊 Management
Mild: observation. WPW: ablation. Severe TR: cone repair. Neonatal severe: Starnes procedure (single ventricle).
Mild: observation. WPW: ablation. Severe TR: cone repair. Neonatal severe: Starnes procedure (single ventricle).
📈 Prognosis
Mild: excellent. Severe neonatal: guarded. Cone repair: excellent results. Lifelong follow-up.
Mild: excellent. Severe neonatal: guarded. Cone repair: excellent results. Lifelong follow-up.
⭐ High-yield pearls for TOACS (Ebstein Anomaly):
• ECG: RBBB + tall P waves + WPW (25%).
• Chest X-ray: Massive cardiomegaly (box-shaped heart).
• Carvallo sign: TR murmur increases with inspiration.
• WPW management: Radiofrequency ablation.
• Cone repair: Gold standard for tricuspid valve repair in older children.
• Starnes procedure: For severe neonatal Ebstein (tricuspid closure + BT shunt).
• ASD closure: Usually performed during surgery, but may be contraindicated if RV dysfunction.
• ECG: RBBB + tall P waves + WPW (25%).
• Chest X-ray: Massive cardiomegaly (box-shaped heart).
• Carvallo sign: TR murmur increases with inspiration.
• WPW management: Radiofrequency ablation.
• Cone repair: Gold standard for tricuspid valve repair in older children.
• Starnes procedure: For severe neonatal Ebstein (tricuspid closure + BT shunt).
• ASD closure: Usually performed during surgery, but may be contraindicated if RV dysfunction.
🗣️ Candidate's role-play & examiner feedback
💬 To the candidate (role‑play): You will be asked the 14 questions from the Examiner Q&A tab. This station tests knowledge of Ebstein Anomaly – ECG interpretation (RBBB, tall P waves, WPW), pathophysiology (apical displacement, atrialized RV, TR, ASD), management (ablation for WPW, cone repair for TR, Starnes for neonatal), and Carvallo sign. Provide compassionate counseling to the patient and family about prognosis and follow-up.
📝 Examiner Marking Grid (Ebstein Anomaly – TOACS station):
- ✅ Interprets ECG: RBBB, tall P waves, WPW (25%)
- ✅ Describes pathophysiology: apical displacement, atrialized RV, TR, ASD
- ✅ Lists associated defects: ASD (80-90%), WPW (25%), pulmonary stenosis/atresia
- ✅ Describes Carvallo sign (TR increases with inspiration)
- ✅ States chest X-ray finding: massive cardiomegaly (box-shaped heart)
- ✅ Manages WPW: radiofrequency ablation
- ✅ Describes cone repair (tricuspid valve repair for older children)
- ✅ Describes Starnes procedure (neonatal severe Ebstein – tricuspid closure + BT shunt)
- ✅ Discusses indications for surgery (severe TR, symptoms, RV dysfunction)
- ✅ Provides compassionate counseling and discusses prognosis
📚 Key references: Nelson Textbook of Pediatrics 22e (Section 479.7 – Ebstein Anomaly), Pediatric Cardiology guidelines.