polymorphic ventricular tachycardia
Also written as: PMVT — polymorphic ventricular tachycardia
Ventricular tachycardia with varying QRS morphology, often associated with QT prolongation or ischemia.
Full Definition
A form of ventricular tachycardia characterized by continuously changing QRS morphology, axis, and amplitude, creating a characteristic 'twisting' appearance on the electrocardiogram. This arrhythmia can occur in the setting of a normal QT interval (usually ischemia-related) or prolonged QT interval (torsades de pointes). Polymorphic ventricular tachycardia is often hemodynamically unstable and may degenerate into ventricular fibrillation. Emergency management focuses on identifying and treating the underlying cause while providing immediate rhythm support through defibrillation if pulseless or cardioversion if hemodynamically stable.
Usage
Usage note: Distinguish from torsades de pointes, which specifically occurs with QT prolongation.
In Context
- "The monitor showed polymorphic ventricular tachycardia with rapid degeneration to ventricular fibrillation." — Resuscitation documentation
- "Polymorphic ventricular tachycardia in the setting of acute MI required immediate defibrillation." — Emergency intervention note