Ebstein’s anomaly

Published on 02/04/2015 by admin

Filed under Internal Medicine

Last modified 22/04/2025

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35 Ebstein’s anomaly

Instruction

Listen to this patient’s heart. He was told he had an innocent murmur during a school medical examination many years ago but now has a large globular heart on chest radiography.

Diagnosis

This patient has isolated tricuspid regurgitation (lesion) that is probably of congenital aetiology as there is no pulmonary hypertension. He has Ebstein’s anomaly with cardiomegaly and cardiac failure (functional status).

Advanced-level questions

What is the pathology in Ebstein’s anomaly?

The tricuspid leaflets are abnormal and are displaced into the body of the RV. The septal leaflet is variably deficient or even absent. The posterior leaflet is also variably deficient and there is large ‘sail-like’ anterior leaflet, which is the hallmark of this condition. The anterior leaflet is rarely affected. The abnormally located tricuspid orifice produces a part of the RV lying between the atrioventricular ring and the origin of the valve, which is continuous with the right atrial chamber. This proximal segment is known as the ‘atrialized’ portion of the RV. Approximately 50% of the patients have either a patent foramen ovale or a secundum atrial septal defect, and 25% have one or more accessory atrioventricular conduction pathways. The anomaly is said to be associated with maternal lithium ingestion.

What are the mechanisms of cyanosis in these patients?

Right-to-left shunting at the atrial level, i.e. through a patent foramen ovale or atrial septal defect.

What are the poor predictors of outcome?

• The earlier the presentation higher the risk of mortality

• A large right atrium or cardiothoracic ratio >60%

• Severe right outflow tract abnormalities.

How would you investigate such a patient?

• Chest radiography (Fig. 35.1) shows the large right atrium with oligaemic lung fields.

• ECG shows right bundle branch block, prolonged PR interval, P pulmonale (indicating right atrial enlargement), large P waves (Himalayan P waves), type B Wolff–Parkinson–White syndrome (where the QRS complex is downward in lead V₁) (Fig. 35.2B). (Note: Wolff–Parkinson–White syndrome comprises a trial of short PR interval, delta wave and wide QRS complex.) Approximately 10% of patients with Ebstein’s anomaly have the Wolff–Parkinson–White syndrome.

• Echocardiography characteristic findings include the abnormal positional relation between the tricuspid valve and mitral valve with septal displacement of the septal tricuspid leaflet.

• Cardiac catheterization has no place in classical cases as in the past it has been associated with serious morbidity and mortality.

Fig. 35.1 Ebstein’s anomaly. (A) A giant right atrium (RA) causes a shoulder along the right cardiac silhouette (arrows). A giant right ventricular (RV) outflow tract causes the left cardiac border to be straight; the pulmonary artery (PA) is very small. (B) The left atrium (LA) and left ventricle (LV) are essentially normal, but the RA and RV are filling in the retrosternal space (arrows).

(With permission from Mettler 2004.)

Fig. 35.2 Wolff–Parkinson–White syndrome. (A) Type A. The delta wave is recognized clearly in leads II, III, aVF, and V₁ through V₄. (B) Type B. The tracing also shows left ventricular hypertrophy. Tachycardia can be seen, which may be caused by a re-entry phenomenon.

What are the indications for surgery?

• Severe functional limitation

• A cardiothoracic ratio >60%

• An atrial communication and if the patient has cyanosis (caused by risk of stroke)

• Accessory pathway is present

• Severe tricuspid regurgitation.

How are such patients treated?

• Tricupsid valve replacement plus closure of atrial septal defect

• Tricuspid annuloplasty with plication of the atrialized portion of the RV.

Wilhelm Ebstein (1836–1912), German physician who also described the Armanni–Ebstein nephropathy (where there is glycogen vacuolation in the proximal convoluted tubules)

L Armanni (1839–1903) was an Italian pathologist.

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