STAT ECG Diagnoses: a review of the differentials to consider when dealing with wide complex tachycardias and when antiarrhythmic medications can be harmful

ECG Weekly Workout with Dr. Amal Mattu


A 41-year-old female is brought into the ED by EMS unresponsive with unknown past medical history. She is found to be febrile, normotensive (126/78), tachycardic (120s-150s), tachypneic (30s with a Kussmaul respiratory pattern), SpO2 = 98% on room air, and POC glucose = “high”. The following ECG is obtained that shows a wide complex tachycardia:

The patient is treated empirically with calcium and insulin for suspected hyperkalemia, but there is no effect after 2 rounds of treatment.

  1. What is your differential for this wide complex tachycardia?
  2. Do you suspect ventricular tachycardia?
  3. Would you treat with an antiarrhythmic medication (amiodarone, lidocaine, procainamide, etc.)?