• In polymorphic VT, QRS complexes vary in shape and amplitude, and originate from multiple foci.
• The QT interval is normal or long.

Rate: 100–250 bpm

Rhythm: Regular or irregular

P Waves: None or not associated with the QRS

PR Interval: None

QRS: Wide (greater than 0.10 sec), bizarre appearance

Clinical Tip: It is important to determine whether pulses are present because polymorphic VT may be perfusing or nonperfusing.

Clinical Tip: Consider electrolyte abnormalities as a possible cause.