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Chapters

0:00 Introduction
0:51 Causes of Ebstein Anomaly
1:50 Symptoms of Ebstein Anomaly
2:09 Diagnosis for Ebstein Anomaly
2:39 Treatment of Ebstein Anomaly

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. It is classified as a critical congenital heart defect[1] accounting for 1% of all congenital heart defects presenting in 1 per 200,000 live births.[2] Ebstein anomaly is the congenital heart lesion most commonly associated with supraventricular tachycardia.
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.[citation needed]

S3 heart sound
S4 heart sound
Triple or quadruple gallop due to widely split S1 and S2 sounds plus a loud S3 and/or S4
Systolic murmur of tricuspid regurgitation = Holosystolic or early systolic murmur along the lower left sternal border depending on the severity of the regurgitation
Right atrial hypertrophy
Right ventricular conduction defects
Wolff-Parkinson-White syndrome often accompanies

Related abnormalities
A diagram showing the downward displacement of the tricuspid valve from its normal position in the fibrous ring down into the right ventricle.

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.[citation needed]
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.[citation needed] Tethering the underlying ventricular wall is the most common for the posterior and septal leaflets, and sail-like anterior leaflets may be tethered to the RV free wall also.[citation needed]
ECGs recorded during sinus rhythm and AVRT in a 9-year-old girl with Ebstein's anomaly and a Mahaim accessory pathway.

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.[3]
Electrophysiologic abnormalities

About 50% of individuals with Ebstein's anomaly have an accessory pathway with evidence of Wolff-Parkinson-White syndrome, secondary to the atrialized right ventricular tissue. This can lead to abnormal heart rhythms including atrioventricular re-entrant tachycardia.[citation needed]
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:

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