Overview
Definition
A fast, abnormal heart rate (≥ 3 consecutive PVCs at > 100 bpm) originating from the ventricles.
Epidemiology
A leading cause of sudden cardiac death. Usually occurs in patients with structural heart disease.
Etiology & Risk Factors
- Ischemic heart disease / Prior MI (scar tissue creates a reentry circuit)
- Dilated or Hypertrophic cardiomyopathy
- Electrolyte abnormalities (Hypokalemia, Hypomagnesemia)
- Prolonged QT syndrome (Torsades de Pointes)
Clinical Symptoms
- Palpitations
- Lightheadedness
- Syncope
- Cardiac arrest (if pulseless)
Clinical Approach
Diagnosis
- ECG: Wide QRS complex (≥ 120 ms) tachycardia, AV dissociation, capture/fusion beats
Management
- Pulseless VT: CPR and Defibrillation (ACLS protocol)
- Unstable with pulse: Synchronized cardioversion
- Stable with pulse: IV Amiodarone or Procainamide
- Long-term: ICD (Implantable Cardioverter Defibrillator) placement, Beta-blockers, Amiodarone
Complications
- Degeneration into Ventricular Fibrillation
- Sudden Cardiac Death
- Cardiogenic shock