Which ECG findings characterize Wolff-Parkinson-White syndrome?

Which ECG findings characterize Wolff-Parkinson-White syndrome?

• A. Long PR interval with narrow QRS and absent delta wave
• B. Short PR interval with delta wave and widened QRS
• C. Prolonged QT interval
• D. ST-segment elevations in multiple leads

Answer: (B)

Wolff-Parkinson-White is a pre-excitation syndrome caused by an accessory conduction pathway that bypasses the normal AV node delay. On an ECG, this shows three features during sinus rhythm: a short PR interval, a delta wave (a slurred upstroke at the beginning of the QRS), and a widened QRS complex. The short PR interval happens because part of the impulse reaches the ventricles via the accessory pathway faster than through the AV node. The delta wave reflects early ventricular activation through that pathway before the normal conduction takes over. Because the ventricles are being activated by two routes, the overall QRS is widened. This pattern distinguishes WPW from other ECG findings like prolonged QT or ST-segment elevations, which point to different conditions and lack the delta wave preexcitation.

Wolff-Parkinson-White is a pre-excitation syndrome caused by an accessory conduction pathway that bypasses the normal AV node delay. On an ECG, this shows three features during sinus rhythm: a short PR interval, a delta wave (a slurred upstroke at the beginning of the QRS), and a widened QRS complex. The short PR interval happens because part of the impulse reaches the ventricles via the accessory pathway faster than through the AV node. The delta wave reflects early ventricular activation through that pathway before the normal conduction takes over. Because the ventricles are being activated by two routes, the overall QRS is widened. This pattern distinguishes WPW from other ECG findings like prolonged QT or ST-segment elevations, which point to different conditions and lack the delta wave preexcitation.