What is the immediate treatment for a patient presenting with ventricular tachycardia?

Immediate Treatment of Ventricular Tachycardia

For hemodynamically unstable VT (hypotension, altered mental status, chest pain, heart failure, or syncope), perform immediate synchronized direct current cardioversion without delay—this is the single most critical intervention that takes priority over all other considerations. 1, 2

Hemodynamic Assessment (First Priority)

Immediately assess for signs of instability: 1, 3, 2

• Hypotension or shock
• Altered mental status
• Ischemic chest pain
• Acute heart failure signs
• Syncope

Management Algorithm Based on Stability

Unstable VT (Immediate Action Required)

Synchronized cardioversion is the definitive first-line treatment: 1, 2

• Use 100 J synchronized discharge for monomorphic VT with rates >150 bpm 2
• Use unsynchronized 200 J for polymorphic VT resembling VF 2
• Provide immediate sedation before cardioversion in hypotensive but conscious patients 1, 2
• If no defibrillator is immediately available, attempt a precordial thump while preparing equipment 1

Stable Monomorphic VT (Pharmacological Options)

For hemodynamically stable patients with monomorphic VT, intravenous procainamide is the preferred first-line agent when early termination is desired, as it demonstrates the greatest efficacy for rhythm conversion: 2

• Administer 10 mg/kg IV at 50-100 mg/min over 10-20 minutes 4, 2
• Monitor blood pressure and ECG continuously during infusion 2
• Procainamide is specifically recommended for patients without severe heart failure or acute MI 4

Intravenous amiodarone is preferred over procainamide in patients with heart failure, suspected myocardial ischemia, or impaired left ventricular function: 1, 2

• Loading dose: 150 mg IV over 10 minutes, followed by maintenance infusion 1
• FDA-approved dosing: approximately 1000 mg over first 24 hours, then 0.5 mg/min maintenance 5
• Amiodarone is recommended for stable mVT with or without heart failure or acute MI 4

Alternative agents for stable VT: 4, 1

• Sotalol may be considered for hemodynamically stable sustained mVT, including post-MI patients 4
• Intravenous lidocaine is only moderately effective and should be considered second-line 1
• Beta-blockers are first-line unless contraindicated, particularly in post-MI settings 1

Stable Polymorphic VT

Direct current cardioversion remains first-line for hemodynamically compromised polymorphic VT: 2

For recurrent polymorphic VT: 2

• Intravenous beta-blockers are recommended, especially if ischemia is suspected or cannot be excluded 2
• Intravenous amiodarone loading is useful in the absence of QT prolongation 2
• Urgent revascularization should be considered when ischemia cannot be excluded 2

For polymorphic VT with long QT (torsades de pointes): 4

• Intravenous magnesium for recurrences 4
• Overdrive pacing (atrial or ventricular) 4
• Beta-blockers for congenital long QT 4

Post-Conversion Management

After successful conversion: 1, 2

• Evaluate and correct underlying causes: ongoing ischemia, electrolyte abnormalities (especially potassium and magnesium), hypoxia, acid-base disturbances 1, 2
• Monitor closely for recurrence 1
• Consider antiarrhythmic drug therapy to prevent acute reinitiation if VT recurs after cardioversion 2

For recurrent or incessant VT: 4

• Intravenous amiodarone or procainamide followed by VT ablation can be effective 4
• Urgent catheter ablation is recommended for scar-related heart disease with incessant VT or electrical storm 1, 2
• Beta-blockers with or without amiodarone for VT storm 4

Critical Pitfalls to Avoid

Never delay cardioversion in unstable patients while attempting pharmacological conversion—this is the most dangerous error in VT management: 1, 2

Avoid calcium channel blockers (diltiazem, verapamil) in patients with VT and suspected structural heart disease, as they may precipitate hemodynamic collapse: 1, 2

• These agents are only appropriate for specific VT subtypes (e.g., LV fascicular VT with RBBB morphology and left axis deviation) 1

Always presume wide-complex tachycardia is VT until proven otherwise—when in doubt, treat as VT: 3, 2

Distinguish accelerated idioventricular rhythm (ventricular rate <120 bpm) from true VT, as it is usually a harmless reperfusion rhythm requiring no treatment: 1

Special Considerations for Ischemic VT

For VT occurring early in acute coronary syndrome: 2

• Correction of ischemia is an early priority 2
• Revascularization and beta blockade followed by IV antiarrhythmic drugs (procainamide or amiodarone) are recommended for recurrent or incessant polymorphic VT due to acute ischemia 4
• Beta-blockers improve mortality in recurrent polymorphic VT with acute MI 2