- The first-line treatment for a patient with unstable ventricular tachycardia is synchronous cardioversion, because it delivers a timed electrical shock synchronized to the QRS complex, restoring normal rhythm without precipitating ventricular fibrillation.
- Unstable VT, characterized by hemodynamic compromise (e.g., hypotension, chest pain, altered consciousness), requires immediate rhythm control.
- Intravenous antiarrhythmics like amiodarone are used once the patient is stabilized or if VT is stable.
- Unsynchronized defibrillation is reserved for pulseless VT or ventricular fibrillation.
- Vagal maneuvers have no role in ventricular arrhythmias.
- Prompt cardioversion prevents clinical deterioration and sudden cardiac death.

Reference: Davidson’s Principles and Practice of Medicine, 24th Edition, Chapter: Cardiac Arrhythmias, Page 600.