What is the treatment for monomorphic ventricular tachycardia (VT)?

Treatment of Monomorphic Ventricular Tachycardia

For hemodynamically unstable monomorphic VT, perform immediate direct-current cardioversion with appropriate sedation; for hemodynamically stable monomorphic VT, intravenous procainamide (10 mg/kg at 50-100 mg/min) is the first-line pharmacologic agent, with electrical cardioversion remaining the most efficacious option overall. 1, 2

Immediate Assessment

• Determine hemodynamic stability first: Look for hypotension (systolic BP <90 mmHg), altered mental status, chest pain, acute heart failure, or signs of shock 1
• Obtain a 12-lead ECG in all hemodynamically stable patients to confirm monomorphic VT and guide treatment decisions 1
• Presume any wide-QRS tachycardia is VT if diagnosis is unclear and treat accordingly 2

Hemodynamically Unstable Monomorphic VT

Direct-current cardioversion is mandatory (Class I recommendation) 1, 2

• Provide immediate sedation if the patient is conscious but hypotensive before cardioversion 1
• If VT recurs after cardioversion, administer intravenous amiodarone: 150 mg loading dose over 10 minutes, followed by maintenance infusion 1, 2, 3
• Amiodarone facilitates defibrillation and prevents VT/VF recurrences in acute situations 1

Hemodynamically Stable Monomorphic VT

First-Line Pharmacologic Treatment

Intravenous procainamide is the preferred initial agent (Class IIa recommendation, Level B evidence) 1, 2

• Dosing: 10 mg/kg at 50-100 mg/min intravenously over 10-20 minutes 1, 2, 4
• Monitor blood pressure and ECG continuously during infusion 4
• Contraindications: Severe heart failure or acute myocardial infarction 1

Alternative Pharmacologic Options

Intravenous amiodarone is recommended for:

• VT refractory to procainamide or cardioversion 2
• Patients with heart failure or suspected ischemia 1
• Dosing: 150 mg loading dose over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min maintenance 3
• Amiodarone carries a IIb recommendation (lower than procainamide) but is effective in patients with structural heart disease 1, 4

Intravenous sotalol may be considered for hemodynamically stable sustained monomorphic VT, including patients with acute MI 1

Intravenous flecainide may be considered only in patients without severe heart failure or acute MI 1

Electrical Cardioversion Remains Superior

• Electrical cardioversion should be first-line even in stable patients as it is most efficacious 1, 4
• Medical management is surrounded by controversy and should be reserved for situations where cardioversion is not immediately available or declined 4

Special Circumstances

LV Fascicular VT (Idiopathic VT)

Intravenous verapamil or beta-blockers are the treatments of choice for patients presenting with LV fascicular VT characterized by RBBB morphology and left axis deviation 1

VT Associated with Acute Myocardial Ischemia/Infarction

• Intravenous lidocaine: 1 mg/kg initial bolus, followed by 0.5 mg/kg every 8-10 minutes if needed 2
• Lidocaine is only moderately effective for general monomorphic VT but has specific utility in ischemic contexts 1
• Urgent coronary angiography with revascularization should be considered 2

Recurrent or Refractory VT

• Combination therapy with intravenous amiodarone, beta-blockers, and procainamide may be considered for repetitive monomorphic VT 2
• Urgent catheter ablation (Class I recommendation) is indicated for patients with scar-related heart disease presenting with incessant VT or electrical storm 1

Critical Contraindications and Pitfalls

Never use calcium channel blockers (verapamil, diltiazem) for wide-QRS tachycardia of unknown origin, especially in patients with history of myocardial dysfunction, as this can cause hemodynamic collapse 2

Avoid procainamide in patients with:

• Severe heart failure 1
• Acute myocardial infarction 1
• These patients should receive amiodarone instead 1

Amiodarone-specific warnings 3:

• Can cause hypotension (occurred in 16% of patients in clinical trials) 3
• Risk of pulmonary toxicity, thyroid dysfunction, and QTc prolongation 3
• Monitor FiO₂ and oxygen delivery closely 3

Intravenous adenosine may be considered relatively safe in undifferentiated regular stable wide-complex tachycardia to aid diagnosis, but should not be used as definitive treatment for confirmed VT 1

Long-Term Management Considerations

• Catheter ablation is recommended (Class I) for patients with ischemic heart disease and recurrent ICD shocks due to sustained VT 1
• Catheter ablation should be considered (Class IIa) after a first episode of sustained VT in patients with ischemic heart disease and an ICD 1
• Most patients require acute IV therapy for 48-96 hours before transitioning to oral amiodarone 3