Management of Monomorphic Recurrent Ventricular Tachycardia
For hemodynamically unstable monomorphic recurrent VT, perform immediate direct-current cardioversion with appropriate sedation; for hemodynamically stable recurrent VT, administer intravenous procainamide (10 mg/kg at 50-100 mg/min) as first-line medical therapy, reserving amiodarone for VT refractory to cardioversion or procainamide. 1, 2
Initial Assessment
- Presume any wide-QRS tachycardia to be VT if the diagnosis is unclear and immediately assess hemodynamic stability (blood pressure, mental status, signs of shock or pulmonary edema). 1, 2
Hemodynamically Unstable Monomorphic Recurrent VT
Perform immediate direct-current cardioversion with appropriate sedation as the definitive treatment at any point in the treatment cascade. 1, 2
If VT recurs after successful cardioversion, administer intravenous amiodarone loading dose of 150 mg over 10 minutes, followed by maintenance infusion (1 mg/min for 6 hours, then 0.5 mg/min). 1, 2, 3
For breakthrough recurrent episodes after amiodarone loading, give supplemental 150 mg amiodarone infusions over 10 minutes to minimize hypotension risk. 3
Hemodynamically Stable Monomorphic Recurrent VT
Administer intravenous procainamide (10 mg/kg at 50-100 mg/min) as first-line medical therapy, with close monitoring of blood pressure and QRS/QT interval prolongation. 1, 2, 4
Procainamide demonstrates superior efficacy compared to lidocaine (RR 3.7,95% CI 1.3-10.5) and terminates 80% of stable monomorphic VT episodes versus 20% with lidocaine. 5, 6
Avoid intravenous amiodarone for early conversion of stable monomorphic VT as it is poorly effective for acute termination (only 29% success rate) due to slow onset of action. 1, 7
If procainamide fails or is unavailable, use intravenous amiodarone for refractory or recurrent VT despite other agents, though direct-current cardioversion remains more efficacious. 1, 2, 4
Special Circumstances
VT Associated with Acute Myocardial Ischemia
Administer intravenous lidocaine (1 mg/kg initial bolus) specifically when VT is thought to be related to acute myocardial ischemia or infarction. 1, 2
Pursue urgent coronary angiography with revascularization as correction of ischemia is an early priority. 1, 2
Correct potentially causative conditions including hypokalemia and ongoing ischemia before or concurrent with antiarrhythmic therapy. 1
Refractory Recurrent VT
Consider transvenous catheter pace termination for sustained monomorphic VT that is refractory to cardioversion or frequently recurrent despite antiarrhythmic medication. 1, 2
For repetitive monomorphic VT in coronary disease or idiopathic VT, combination therapy with intravenous amiodarone, beta blockers, and procainamide may be useful. 1, 2
Critical Contraindications and Pitfalls
Never use calcium channel blockers (verapamil, diltiazem) to terminate wide-QRS-complex tachycardia of unknown origin, especially in patients with myocardial dysfunction, as this can cause hemodynamic collapse. 1, 2
When administering amiodarone, use a central venous catheter for concentrations >2 mg/mL to avoid peripheral vein phlebitis, and always use a volumetric infusion pump (not drop counters which can underdose by 30%). 3
Monitor for hypotension during procainamide infusion, particularly in patients with congestive heart failure or baseline hypotension. 1
Do not exceed initial amiodarone infusion rate of 30 mg/min and avoid mean daily doses above 2100 mg due to increased hypotension risk. 3