What is Wolff-Parkinson-White syndrome identified by on an ECG?

• A. Presence of a delta wave and short PR interval
• B. Elevation of the ST segment with tall T waves
• C. Prolonged QT interval with low heart rate
• D. Absent QRS complex in multiple leads

Answer: (A)

Wolff-Parkinson-White (WPW) syndrome is characterized by a specific set of findings on the electrocardiogram (ECG). The presence of a delta wave is the hallmark of WPW, which represents an accessory pathway conducting electrical impulses from the atria to the ventricles prematurely. This early conduction leads to characteristic changes in the ECG, including a short PR interval. The delta wave is seen as a slurring of the initial upstroke of the QRS complex, caused by the early depolarization of the ventricles before the typical conduction through the atrioventricular node and the His-Purkinje system occurs.

In this context, the presence of both the delta wave and the short PR interval are key diagnostic criteria for WPW syndrome, making this the correct answer. Other ECG features, such as normal QRS complex morphology, may also be present, but the delta wave and short PR interval are critical for diagnosis.

The other choices do not accurately represent the ECG findings associated with WPW. While elevated ST segments and tall T waves could relate to different cardiac conditions, they are not indicative of WPW. Similarly, a prolonged QT interval generally suggests issues with repolarization but does not pertain to