What are the latest Advanced Life Support (ALS) guidelines for treating a patient with ventricular tachycardia (VT) with a pulse?

Latest ALS Guidelines for VT with Pulse

For hemodynamically unstable VT with a pulse, perform immediate synchronized cardioversion starting at 100 J (biphasic) without delay—this is the definitive treatment and takes priority over all pharmacologic options. 1

Immediate Assessment

Rapidly assess hemodynamic stability by checking for:

• Hypotension 1
• Altered mental status 1
• Chest pain 1
• Signs of shock 1
• Heart failure 1

Obtain a 12-lead ECG immediately to confirm VT and distinguish monomorphic from polymorphic patterns. 1 Establish IV access and ensure resuscitation equipment is readily available. 1

Treatment Algorithm Based on Stability

Hemodynamically Unstable VT (Hypotension, Altered Mental Status, Shock, Heart Failure)

Deliver synchronized cardioversion immediately without attempting pharmacologic therapy first. 1

For monomorphic VT:

• Use synchronized cardioversion starting at 100 J with a biphasic defibrillator 1
• If unsuccessful, increase energy for subsequent shocks 2

For polymorphic VT:

• Use unsynchronized high-energy shocks (defibrillation doses of 200 J) 1
• Never use synchronized cardioversion for polymorphic VT 1
• Treat polymorphic VT identically to ventricular fibrillation 2

Hemodynamically Stable Monomorphic VT

Procainamide is the first-line pharmacologic agent for stable monomorphic VT, unless contraindicated. 1, 3

Procainamide dosing:

• Administer 10 mg/kg IV at 50-100 mg/min over 10-20 minutes 1, 3
• Monitor blood pressure and ECG continuously during infusion 1, 3
• Stop infusion if hypotension develops or QRS widens >50% 3

Alternative agents if procainamide is unavailable or contraindicated:

• Amiodarone: 150 mg IV over 10 minutes, may repeat once 2, 4
• Lidocaine: 1-1.5 mg/kg IV bolus 2
• Sotalol (Class IIb recommendation) 2, 3

Important caveat: While procainamide has the highest efficacy for stable monomorphic VT, amiodarone received only a Class IIb recommendation in AHA guidelines compared to procainamide's Class IIa recommendation. 2, 3 However, direct current cardioversion remains most efficacious even in stable patients. 3

Special Considerations for Polymorphic VT

Polymorphic VT with Long QT Interval (Torsades de Pointes)

First steps:

• Stop all QT-prolonging medications immediately 2
• Correct electrolyte abnormalities (particularly magnesium and potassium) 2
• Identify and treat acute precipitants (drug overdose, poisoning) 2

Pharmacologic treatment:

• Administer IV magnesium sulfate (supported by observational studies showing effectiveness in prolonged QT interval) 2
• Consider ventricular pacing or IV isoproterenol for bradycardia-associated torsades 2
• Never use isoproterenol for familial long QT syndrome 2

Polymorphic VT with Normal QT Interval

The most common cause is myocardial ischemia. 2

Treatment approach:

• IV amiodarone may reduce arrhythmia recurrence (Class IIb, LOE C) 2
• Beta-blockers may reduce recurrence frequency 2
• Treat underlying ischemia aggressively 2

Post-Cardioversion Management

After successful rhythm conversion:

• Obtain 12-lead ECG to assess for ST-segment elevation or ischemic changes 1
• Check cardiac enzymes to assess for myocardial ischemia 1
• Correct electrolyte abnormalities 1
• Start IV beta-blockers to prevent recurrence 1
• Focus on addressing underlying causes 1

Critical Pitfalls to Avoid

Never use Class IC antiarrhythmic drugs (flecainide, propafenone) in patients with history of myocardial infarction. 1 These agents are contraindicated and can cause fatal proarrhythmia.

Never use synchronized cardioversion for polymorphic VT—use defibrillation instead. 1 The device may fail to sense an appropriate QRS complex in polymorphic rhythms.

Never administer calcium channel blockers for VT. 1 These can cause hemodynamic collapse or degeneration to ventricular fibrillation.

Do not delay cardioversion in unstable patients to establish IV access or administer medications. 5 Electrical therapy is definitive and should not be postponed.

Avoid using amiodarone as first-line therapy for stable monomorphic VT when procainamide is available. 1, 3 Procainamide demonstrates superior efficacy and has a higher guideline recommendation class.

Pulseless VT

If pulse is absent, treat identically to ventricular fibrillation: 1, 5

• Begin high-quality CPR immediately 5
• Deliver unsynchronized high-energy shocks (200 J biphasic, 360 J monophasic) 5
• Resume CPR immediately after shock without pulse check 5
• Administer epinephrine 1 mg IV every 3-5 minutes 5
• Consider amiodarone 300 mg IV bolus after first shock 5
• Never use synchronized cardioversion for pulseless VT 5