Interpretation: Humans, 1; Machine, 0

ANSWER
The correct interpretation of this ECG is atrial fibrillation with a rapid ventricular response and aberrantly conducted QRS complexes. The latter were misinterpreted as ventricular tachycardia. Although they represent a wide complex at a rate of more than 100 beats/min, the rhythm is irregular and the intrinsic (initial) inflection of normally conducted and aberrant beats is the same. (See lead I rhythm strip at bottom.)

What is unusual (and doesn’t make sense) regarding this ECG is the machine’s reading of the PR interval (128 ms) and the QRS duration (88 ms). For one thing, there is no measurable PR interval. And for another, the measured QRS duration accounts for the normally conducted complex and not the aberrantly conducted ones.

The technician was reassured, and the patient underwent successful cardioversion back to normal sinus rhythm.