What is the treatment for a patient presenting with ventricular tachycardia (V tach)?

Treatment for Ventricular Tachycardia

For hemodynamically unstable VT (hypotension, chest pain, heart failure, or heart rate ≥150 bpm), perform immediate synchronized DC cardioversion starting at 100J, escalating to 200J then 360J if needed. 1, 2, 3

Initial Assessment: Determine Hemodynamic Stability

The critical first step is assessing whether the patient is stable or unstable, as this dictates immediate management 1, 2, 3:

Unstable VT is defined by:

• Systolic blood pressure ≤90 mmHg 2
• Chest pain or acute heart failure 4, 2
• Heart rate ≥150 beats/min 2, 3
• Altered mental status or signs of shock 4

For pulseless VT: Follow the ventricular fibrillation protocol with immediate unsynchronized defibrillation 2, 3

Treatment Algorithm for Hemodynamically Unstable VT

Immediate synchronized cardioversion is mandatory without delay 1, 2, 3:

• Start with 100J synchronized shock 2, 3
• If unsuccessful, escalate to 200J 2, 3
• If still unsuccessful, escalate to 360J 2, 3
• Sedate the conscious but unstable patient immediately before cardioversion 4, 2
• If VT recurs after successful cardioversion, administer antiarrhythmic drugs to prevent reinitiation 2

A precordial thump may be attempted if no defibrillator is immediately available 4

Treatment Algorithm for Hemodynamically Stable Monomorphic VT

First-Line Pharmacological Treatment

Procainamide is the preferred first-line agent for stable monomorphic VT, demonstrating the greatest efficacy among antiarrhythmics 1, 2, 3:

• Dosing: 10 mg/kg IV at 50-100 mg/min over 10-20 minutes (maximum dose 10-20 mg/kg) 1, 2, 3
• Monitor continuously for hypotension and QRS widening during administration 2, 3
• Critical contraindication: Avoid procainamide in patients with severe heart failure or acute myocardial infarction—use amiodarone instead 1, 2

Alternative Agents When Procainamide is Contraindicated

Amiodarone is preferred in patients with heart failure or suspected ischemia 1, 2, 3:

• Dosing: 150 mg (5 mg/kg) IV over 10 minutes, then 1 mg/min infusion for 6 hours, then 0.5 mg/min 2, 5
• Amiodarone reduces life-threatening arrhythmias, required shocks, and symptomatic VT episodes 1, 2
• Important caveat: Amiodarone's antiarrhythmic effect may take up to 30 minutes, making it less suitable for emergent situations 3
• For breakthrough VT/VF during maintenance infusion, give 150 mg supplemental bolus over 10 minutes 5

Sotalol may be considered for stable monomorphic VT, but exercise caution due to significant beta-sympatholytic properties 1, 2

Lidocaine is only moderately effective and less effective than procainamide, sotalol, or amiodarone 1, 3

Beta-Blockers for Specific Contexts

Beta-blockers are first-line therapy unless contraindicated, particularly in the post-MI setting 4:

• Effective for preventing recurrence and late conversion in refractory ventricular tachyarrhythmias 1
• Cornerstone of treatment for catecholaminergic polymorphic VT 1, 2, 3

Special Considerations for Polymorphic VT

Polymorphic VT with Normal QT Interval (Likely Ischemia-Related)

• Consider IV beta-blockers 2, 3
• Treat underlying ischemia aggressively 2

Polymorphic VT with Prolonged QT (Torsades de Pointes)

Administer IV magnesium sulfate: 8 mmol bolus followed by 2.5 mmol/h infusion 2, 3

• Correct electrolyte abnormalities (potassium, magnesium) 2
• Consider pacing for familial long QT syndrome 3
• Avoid isoproterenol in familial long QT syndrome 3

Non-Sustained VT

Runs of non-sustained VT may be well tolerated and do not necessarily require treatment 4:

• Beta-blockers are first-line therapy unless contraindicated 4
• Differentiate from accelerated idioventricular rhythm (ventricular rate <120 bpm), which is usually a harmless consequence of reperfusion and requires no treatment 4

Long-Term Management After Acute Stabilization

Urgent catheter ablation is recommended for incessant VT or electrical storm in scar-related heart disease 1, 2:

• Catheter ablation is recommended for recurrent ICD shocks due to sustained VT in ischemic heart disease 1
• Consider ICD implantation for secondary prevention in structural heart disease 2, 3

For catecholaminergic polymorphic VT with recurrent syncope despite beta-blockers:

• Consider combination therapy with flecainide, left cardiac sympathetic denervation, and/or ICD 1

Critical Pitfalls to Avoid

Never assume wide-complex tachycardia is supraventricular—when in doubt, treat as VT 2

Avoid calcium channel blockers (verapamil, diltiazem) in VT with structural heart disease, as they may precipitate hemodynamic collapse and worsen outcomes 2

Do not use procainamide in patients with severe heart failure or acute MI—use amiodarone instead 1, 2

Measure and normalize serum potassium and magnesium before initiating antiarrhythmics 2

Monitoring Requirements

• Continuous ECG monitoring is mandatory for all VT treatment 2
• Monitor QTc interval—discontinue drug if QTc prolongs to ≥500 ms 2
• Facility must have cardiac resuscitation capabilities immediately available 2
• Use a volumetric infusion pump for amiodarone administration 5
• Administer amiodarone through a central venous catheter for concentrations >2 mg/mL 5