Preexcitation Pitfalls (Part 4): Potpourri Cases & Final Teaching Points

ECG Weekly Workout with Dr. Amal Mattu

HPI

A 49-year-old man arrives with palpitations and chest discomfort. The monitor shows an irregular, wide-complex tachycardia with varying morphology and rates nearing 250 to 300 bpm. The team debates polymorphic VT versus another high-risk rhythm and reaches for a familiar antiarrhythmic. The following ECG is obtained on arrival:

Before watching this week’s workout, review the arrival ECG carefully and consider:

    1. What ECG features help you separate preexcited atrial fibrillation from polymorphic VT on a single-lead rhythm strip or 12-lead ECG?
    2. Which commonly used ED medications can turn this rhythm into ventricular fibrillation, and why?
    3. In what scenarios can WPW show a normal PR interval, and what should you look for instead?