Ebstein's anomaly

Ebstein's anomaly
Pathological specimen and ultrasound image of a heart with Ebstein's anomaly: Abbreviations: RA: right atrium; ARV: atrialized right ventricle; FRV: fight ventricle; AL: anterior leaflet; SL: septal leaflet; LA: left atrium; LV: left ventricle; asterisk: grade II tethering of the tricuspid septal leaflet
Classification and external resources
Specialty cardiology
ICD-10 Q22.5
ICD-9-CM 746.2
OMIM 224700
DiseasesDB 4039
MedlinePlus 007321
eMedicine med/627
MeSH D004437

Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart.

Presentation

The annulus of the valve is still in the normal position. The valve leaflets, however, are to a varying degree, attached to the walls and septum of the right ventricle. A subsequent 'atrialization' of a portion of the morphologic right ventricle (which is then contiguous with the right atrium) is seen. This causes the right atrium to be large and the anatomic right ventricle to be small in size.

Risk factors

An enlargement of the aorta may occur; an increased risk of abnormality is seen in infants of women taking lithium during the first trimester of pregnancy[1] (though some have questioned this)[2] and in those with Wolff-Parkinson-White syndrome.

History

Ebstein's anomaly was named after Wilhelm Ebstein,[3][4] who in 1866 described the heart of the 19-year-old Joseph Prescher.

While Ebstein's anomaly is defined as the congenital displacement of the tricuspid valve towards the apex of the right ventricle, it is often associated with other abnormalities.

Anatomic abnormalities

Typically, anatomic abnormalities of the tricuspid valve exist, with enlargement of the anterior leaflet of the valve. The other leaflets are described as being plastered to the endocardium.

About 50% of individuals with Ebstein's anomaly have an associated shunt between the right and left atria, either an atrial septal defect or a patent foramen ovale. [5]

Electrophysiologic abnormalities

About 50% of individuals with Ebstein's anomaly have evidence of Wolff-Parkinson-White syndrome, secondary to the atrialized right ventricular tissue.

A 10-lead ECG of a woman with Ebstein's anomaly: The ECG shows signs of right atrial enlargement, best seen in V1. Other P waves are broad and tall, these are termed "Himalayan" P waves. Also, a right bundle-branch block pattern and a first-degree atrioventricular block (prolonged PR-interval) due to intra-atrial conduction delay are seen. No evidence of a Kent-bundle is seen in this patient. The T wave inversion in V1-4 and a marked Q wave in III occur; these changes are characteristic for Ebstein's anomaly and do not reflect ischemic ECG changes in this patient.

Other abnormalities that can be seen on the ECG include:

  1. signs of right atrial enlargement or tall and broad 'Himalayan' P waves
  2. first degree atrioventricular block manifesting as a prolonged PR-interval
  3. low amplitude QRS complexes in the right precordial leads
  4. atypical right bundle branch block
  5. T wave inversion in V1-V4 and Q waves in V1-V4 and II, III and aVF.[6]

Management

Pharmacological

Ebstein's cardiophysiology typically presents as an (antidromic) AV reentrant tachycardia with associated pre-excitation. In this setting, the preferred pharmacological treatment agent is procainamide. Since AV-blockade may promote conduction over the accessory pathway, drugs such as beta blockers, calcium channel blockers, and digoxin are contraindicated.

If atrial fibrillation with pre-excitation occurs, treatment options include procainamide, flecainide, propafenone, dofetilide, and ibutilide, since these medications slow conduction in the accessory pathway causing the tachycardia and should be administered before considering electrical cardioversion. Intravenous amiodarone may also convert atrial fibrillation and/or slow the ventricular response.

Surgical

The Canadian Cardiovascular Society (CCS) recommends surgical intervention for these indications:[7]

The CCS further recommends patients who require operation for Ebstein's anomaly should be operated on by congenital heart surgeons who have substantial specific experience and success with this operation. Every effort should be made to preserve the native tricuspid valve.[7]

References

  1. ↑ Attenhofer Jost CH, Connolly HM, Dearani JA, Edwards WD, Danielson GK (2007). "Ebstein's anomaly". Circulation. 115 (2): 277–85. doi:10.1161/CIRCULATIONAHA.106.619338. PMID 17228014.
  2. ↑ Yacobi S, Ornoy A (2008). "Is lithium a real teratogen? What can we conclude from the prospective versus retrospective studies? A review". Isr J Psychiatry Relat Sci. 45 (2): 95–106. PMID 18982835.
  3. ↑ synd/435 at Who Named It?
  4. ↑ W. Ebstein. Über einen sehr seltenen Fall von Insufficienz der Valvula tricuspidalis, bedingt durch eine angeborene hochgradige Missbildung derselben. Archiv für Anatomie, Physiologie und wissenschaftliche Medicin, Leipzig, 1866, 238-254.
  5. ↑ كتاب A Practical Approach to Clinical Echocardiography, p.119 Jaypee Brothers, First Edition 2014, ISBN 978-93-5152-140-2.
  6. ↑ Khairy P, Marelli AJ (December 2007). "Clinical use of electrocardiography in adults with congenital heart disease". Circulation. 116 (23): 2734–46. doi:10.1161/CIRCULATIONAHA.107.691568. PMID 18056539.
  7. 1 2 Silversides, C. K.; Salehian, O.; Oechslin, E.; Schwerzmann, M.; Vonder Muhll, I.; Khairy, P.; Horlick, E.; Landzberg, M.; Meijboom, F.; Warnes, C.; Therrien, J. (2010). "Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: Complex congenital cardiac lesions". The Canadian journal of cardiology. 26 (3): e98–117. doi:10.1016/S0828-282X(10)70356-1. PMC 2851473Freely accessible. PMID 20352139.
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