Etiology
Pathophysiology
Clinical features
- Often asymptomatic
- Cardiovascular features
- Palpitations
- Tachycardia (HR ≥100/min; typically regular)
- Chest pain/pressure
- Dyspnea, orthopnea
- Symptoms of reduced cardiac output
- Dizziness
- Hypotension
- Syncope
- Cardiogenic shock and loss of consciousness
- Cardiac arrest
Diagnostics
- Polymorphic VT with QRS complexes that typically appear to twist around the isoelectric line, usually in self-limiting bursts
- Often preceded by bigeminy and followed by several premature ventricular contractions
- R-on-T phenomenon may also be seen.
Treatment
- Hemodynamically unstable patients: Defibrillation plus CPR.
- Hemodynamically stable patients: Administer IV magnesium sulfate.
- Identify and treat the underlying etiology of QT prolongation.