What is the initial management for a patient with sustained ventricular tachycardia (V-tach)?

Initial Management of Sustained Ventricular Tachycardia

The initial management of sustained ventricular tachycardia requires immediate assessment of hemodynamic stability, with direct current cardioversion recommended for patients with hemodynamic compromise. 1

Initial Assessment

• Assess hemodynamic stability by evaluating blood pressure, mental status, and signs of hypoperfusion 2
• Any wide-QRS tachycardia should be presumed to be VT if the diagnosis is unclear 1
• Obtain a 12-lead ECG for all patients with sustained VT who are hemodynamically stable 1
• Classify VT as monomorphic (consistent QRS morphology) or polymorphic (changing QRS morphology) 2

Management Algorithm Based on Hemodynamic Status

For Hemodynamically Unstable Patients

• Perform immediate synchronized direct-current cardioversion with appropriate sedation 1
• Start with 100-200 J for synchronized cardioversion of monomorphic VT 2
• For polymorphic VT, use unsynchronized defibrillation at 200 J (treat similar to VF) 1
• Have resuscitation equipment readily available 2

For Hemodynamically Stable Patients

• Pharmacological therapy can be attempted first 1

• For monomorphic VT:

  • Intravenous procainamide (20-30 mg/min loading infusion up to 12-17 mg/kg) is reasonable as first-line treatment 1
  • Intravenous amiodarone (150 mg over 10 minutes, followed by 1.0 mg/min for 6 hours, then 0.5 mg/min) is reasonable for patients with heart failure or when VT is refractory to countershock 1
  • Intravenous lidocaine (1.0-1.5 mg/kg bolus, followed by 0.5-0.75 mg/kg every 5-10 minutes to maximum 3 mg/kg, then 2-4 mg/min infusion) might be reasonable if VT is associated with acute myocardial ischemia 1

• For polymorphic VT:

  • Intravenous beta-blockers are useful, especially if ischemia is suspected 1
  • Intravenous amiodarone is useful in the absence of QT prolongation 1
  • Consider urgent coronary angiography if myocardial ischemia cannot be excluded 1

Post-Conversion Management

• Evaluate for underlying causes of VT, including myocardial ischemia (check cardiac enzymes) 2
• Consider maintenance antiarrhythmic therapy to prevent recurrence 2
• Cardiology consultation is recommended, particularly for patients with structural heart disease 2

Common Pitfalls to Avoid

• Do not delay cardioversion in hemodynamically unstable patients 2, 3
• Avoid calcium channel blockers such as verapamil and diltiazem for wide-QRS-complex tachycardia of unknown origin, especially in patients with a history of myocardial dysfunction 1, 2
• Do not underestimate "stable" VT - even hemodynamically stable VT is associated with high mortality and may be a marker for a substrate capable of producing more malignant arrhythmias 4
• Monitor patients closely after conversion as recurrence is common 5

Special Considerations

• For VT associated with acute myocardial infarction, beta-blockers improve mortality 2
• Transvenous catheter pace termination can be useful for sustained monomorphic VT that is refractory to cardioversion or frequently recurrent despite antiarrhythmic medication 1
• Urgent catheter ablation is recommended in patients with scar-related heart disease presenting with incessant VT or electrical storm 1
• Consider ICD evaluation for patients with structural heart disease and sustained VT, as this is associated with high risk of recurrence and sudden death 1, 6