Ebsteins anomaly of the tricuspid valve electrocardiogram

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] and Claudia P. Hochberg, M.D. [2]

Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [3]

Electrocardiogram

The EKG is abnormal in 50 to 67%.

About 50% of individuals with Ebstein's anomaly have evidence of Wolff-Parkinson-White Syndrome (syndrome of pre-excitation of the ventricles due to an accessory pathway known as the Bundle of Kent), secondary to the the apical displacement of the septal tricuspid valve leaflet resulting in discontinuity of the central fibrous body.

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. There is also a right bundle branch block pattern and a first degree atrioventricular block (prolonged PR-interval) due to intra-atrial conduction delay. There is no evidence of a Kent-bundle in this patient. There is T wave inversion in V1-4 and a marked Q wave in III; 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) a short PR interval and a delta wave and low voltages.