McGill Case 321

This case report is kindly provided by Michael Rosengarten from McGill and is part of the McGill Cases. These cases come from the McGill EKG World Encyclopedia. Previous Case: McGill Case 320 | Next Case: McGill Case 322

This is an electrocardiogram from a young woman with Ebstein's anomaly. In this condition the right atrium is enlarged with downward a displacement of the tricuspid valve into the right ventricle. This partially explains the tall peaked p waves in the inferior leads. Note the P wave in lead II is greater than 2 mm in height. There is also a first-degree heart block which is often seen with these patients. Curiously higher grade blocks are rare. The QRS complex shows a right axis deviation and a terminal S wave in the V 6 derivation. Atypical right bundle branch block can be seen with this condition.