What is the initial management for ventricular tachycardia (VT) with a pulse?

Management of Ventricular Tachycardia with a Pulse

Immediate Assessment: Hemodynamic Stability

The initial management of VT with a pulse depends entirely on whether the patient is hemodynamically stable or unstable. 1

Hemodynamically Unstable VT with Pulse

For unstable monomorphic VT with a pulse, perform immediate synchronized cardioversion starting at 100 J (biphasic or monophasic). 1, 2

• Hemodynamic instability is defined as: hypotension (systolic BP <90 mmHg), pulmonary edema, ongoing chest pain/ischemia, or altered mental status 1
• Synchronized cardioversion must be used for monomorphic (regular) VT with a pulse to avoid inducing ventricular fibrillation 1, 2
• If the initial 100 J shock fails, increase energy in a stepwise fashion for subsequent attempts 1, 2
• Brief sedation/anesthesia is necessary for stable patients, but do not delay cardioversion in hemodynamically unstable patients 1

Critical Exception: Polymorphic VT

If the VT is polymorphic (irregular), treat it as ventricular fibrillation with unsynchronized high-energy shocks (defibrillation doses of 200 J monophasic or 120-200 J biphasic), even if a pulse is present. 1, 2

• Polymorphic VT will not permit synchronization due to varying QRS morphology 1
• Never attempt synchronized cardioversion for polymorphic VT—synchronization is not possible and delays treatment 1, 2

Hemodynamically Stable VT with Pulse

For stable monomorphic VT, pharmacologic therapy is the initial approach:

First-line pharmacologic options include: 1

• Amiodarone: 150 mg IV over 10 minutes, followed by 1 mg/min infusion for 6 hours, then 0.5 mg/min maintenance 1, 3
• Procainamide: 20-30 mg/min loading infusion up to 12-17 mg/kg, followed by 1-4 mg/min infusion 1
• Lidocaine: 1.0-1.5 mg/kg bolus, with supplemental boluses of 0.5-0.75 mg/kg every 5-10 minutes (maximum 3 mg/kg), followed by 2-4 mg/min infusion 1

If pharmacologic therapy fails or is contraindicated, proceed to synchronized cardioversion at 100 J 1

Key Safety Considerations

What NOT to Do

• Never use synchronized cardioversion for pulseless VT—treat as VF with immediate unsynchronized shocks 1, 2
• Never use synchronized cardioversion for ventricular fibrillation—the device may not sense a QRS and fail to deliver a shock 1, 2
• Never use synchronized cardioversion for polymorphic VT—synchronization is not possible 1, 2

Equipment Preparation

• Have defibrillator immediately available when treating any VT, as the patient may deteriorate to pulseless VT or VF at any moment 2
• Ensure the defibrillator shows visible artifact indicating proper synchronization with QRS complexes before delivering synchronized shocks 2
• Use a central venous catheter for amiodarone concentrations >2 mg/mL to avoid peripheral vein phlebitis 3

Common Pitfalls

• Confusing monomorphic with polymorphic VT: Monomorphic VT has a regular, uniform QRS morphology and responds to synchronized cardioversion; polymorphic VT has varying QRS morphology and requires unsynchronized shocks 1
• Delaying cardioversion for sedation in unstable patients: Hemodynamically unstable patients require immediate cardioversion without waiting for sedation 1
• Using amiodarone in already hypotensive patients: Amiodarone can worsen hypotension in unstable patients; cardioversion is preferred 4
• Attempting synchronization on polymorphic rhythms: This wastes critical time and may result in no shock delivery 1, 2