This 41-year-old man known to have a dilated cardiomyopathy for several years is seen in the Emergency Department complaining of dyspnea and weakness, starting suddenly 1 hour earlier:

• Polymorphic ventricular tachycardia, rate 180/min. After the first 9 seconds of the recording, the VT ends and is replaced by narrow complex rhythm with evidence of ST depression

Comment: polymorphic ventricular tachycardia can occur in the setting of either a prolonged or normal QT interval. In the setting of a normal baseline QT interval, one of the principal causes of polymorphic ventricular tachycardia is myocardial ischemia/infarction

This ECG was recorded immediately after the end of the ventricular tachycardia:

• Atrial Fibrillation, 86/min
• Right bundle branch block
• Left posterior fascicular block
• Bifascicular block (RBBB and LPFB)
• ST elevation in AVR with ST depression in remaining leads highly suspicious for global myocardial ischemia (eg: left main coronary disease)