Classic Electrocardiographic Findings in Wolff-Parkinson-White Syndrome

Diagnostic Criteria

The European Society of Cardiology recommends that the classic ECG findings in Wolff-Parkinson-White syndrome include a shortened PR interval (<120 ms), delta wave (slurred upstroke of the QRS complex), and widened QRS complex (>120 ms) 1, 2, 3
A short PR interval, less than 120 ms, is caused by the accessory pathway bypassing the AV node and conducting the electrical impulse prematurely to the ventricles, according to the European Heart Journal 1, 2
The presence of a delta wave, a slurred, slow upstroke at the initial portion of the QRS complex, represents early ventricular activation through the accessory pathway before normal AV nodal conduction arrives, as stated by the European Heart Journal 1, 2
A widened QRS complex, duration greater than 120 ms, results from fusion of two wavefronts—one through the accessory pathway and one through the normal AV node-His-Purkinje system, as reported by the European Heart Journal and the Journal of the American College of Cardiology 1, 2, 3

Incomplete RBBB with ST elevation in V1-V3 describes Brugada pattern, not WPW, according to the Journal of the American College of Cardiology 4
LVH with deep narrow Q waves suggests hypertrophic cardiomyopathy or prior infarction, as stated by Circulation 5
Sinus tachycardia with low voltage and electrical alternans is classic for pericardial effusion with tamponade physiology, according to Circulation 5