Preexcitation Pitfalls (Part 1): The “Inferior STEMI” That Isn’t

ECG Weekly Workout with Dr. Amal Mattu

HPI

A critically ill 38-year-old man presents hypotensive, pale, and diaphoretic with abdominal pain and rectal bleeding. Upright chest X-ray shows free air under the diaphragm, and the patient is headed urgently to the OR. The following pre-op ECG is obtained and the computer interpretation calls an acute inferior STEMI:

Before watching this week’s workout, review the pre-operative ECG carefully and consider:

    1. In a patient who is not in arrest, what is the single highest-yield 20 to 30 second ECG routine that prevents reflexively accepting a scary computer read?
    2. What interval finding should immediately push you toward an accessory-pathway diagnosis, even when the ST segments look alarming?
    3. What are the most common ways preexcitation can masquerade as prior infarction patterns and falsely steer management?