Preexcitation

Preexcitation

prexcitation
Preexcitation

This ECG has a superficial resemblance to left bundle branch block, with tall slurred QRS complexes in lateral leads. The QS complexes in inferior leads mimic inferior wall myocardial infarction. Actually it is a non infarction Q wave or pseudoinfarction pattern. The PR interval is short and is immediately followed by the slurred initial portion of the QRS in lateral leads, which is the positive delta wave. These features are suggestive of ventricular preexcitation as in Wolff–Parkinson–White syndrome (WPW Syndrome). The delta wave is negative in inferior leads and V1. Tall QRS in lateral leads also mimic left ventricular hypertrophy.