A 50yoM with h/o MI >5 years ago presents with a heart rate of 150, only complaining of palpitations, and otherwise normal vital signs. States he was told he had some type of arrhythmia in the past with similar symptoms, and was given a medication that quickly resolved the symptoms. The ECG is shown below. You are unsure of what this is. What non-pharmacological, noninvasive tool can you use to help diagnose this?

 

Answer: The Lewis Lead. You readjust the electrodes to acquire the Lewis Lead to reveal the p waves with A-V dissociation. This is VT.

http://emcrit.org/wee/lewis-lead/

See past pearl from 3/2/12 for extensive discussion on management and other methods of diagnosis.