QRS–ST–T triangulation with repolarization shortening as a precursor of sustained ventricular tachycardia during acute myocardial ischemia

Abstract

We present segments from a 24-hour 12-lead digital Holter recording in a 48-year-old man demonstrating transient ST elevations in the inferior leads that triggered sustained ventricular tachycardia/ventricular fibrillation (VT/VF) requiring cardioversion. The onset of VT was preceded by a gradual increase in the ST with marked QRS broadening that lacked distinction between the end of the QRS and the beginning of the ST (QRS–ST–T “triangulation”), and shortening of the QT interval not caused by an increased heart rate. This is a relatively rare documentation of the mechanisms immediately triggering sustained ventricular arrhythmias during acute myocardial ischemia obtained with 12-lead ECG.

Keywords

• Ventricular arrhythmia
• Myocardial ischemia
• Mechanisms of re-entry
• ST segment elevation
• Vasospastic angina