What is the immediate treatment for a patient with ventricular tachycardia (Vtach) with a pulse?

Immediate Treatment for Ventricular Tachycardia with Pulse

For hemodynamically unstable VT with pulse (hypotension, chest pain, heart failure, altered mental status), perform immediate synchronized cardioversion starting at 100J, then 200J, then 360J with sedation if the patient is conscious. 1, 2 For hemodynamically stable VT with pulse, intravenous amiodarone combined with beta-blockers is the preferred first-line pharmacological therapy, with procainamide as the most efficacious alternative. 3, 4, 5

Hemodynamic Assessment

The critical first step is determining hemodynamic stability by assessing for adverse signs: 3, 2

• Hypotension (systolic BP ≤90 mmHg)
• Chest pain suggesting ongoing ischemia
• Acute heart failure (pulmonary edema, dyspnea)
• Altered mental status
• Signs of shock

This assessment dictates whether electrical or pharmacological intervention takes priority. 4

Unstable VT with Pulse: Immediate Cardioversion

If any adverse signs are present, electrical therapy is mandatory: 1, 2

• Perform synchronized DC cardioversion immediately at escalating energy levels: 100J → 200J → 360J 1, 2
• Provide sedation before cardioversion if the patient is conscious but unstable 3, 2
• Have resuscitation equipment immediately available 1
• Do not delay cardioversion to establish IV access or administer medications 1

After successful cardioversion, consider antiarrhythmic therapy to prevent recurrence, as patients often have premature complexes that can reinitiate tachycardia. 1

Stable VT with Pulse: Pharmacological Management

First-Line Therapy: Amiodarone + Beta-Blockers

Amiodarone is the preferred antiarrhythmic for hemodynamically stable VT, particularly in patients with structural heart disease or heart failure: 3, 4, 6

• Loading dose: 150 mg IV over 10 minutes 3, 4, 6
• Maintenance infusion: 1.0 mg/min for 6 hours, then 0.5 mg/min 3, 4, 6
• Combine with IV beta-blockers for optimal efficacy, as beta-blockers are the single most effective therapy for polymorphic VT storm 3, 4

Alternative First-Line: Procainamide

Procainamide demonstrates the greatest efficacy among medical options for stable monomorphic VT and receives a Class IIa recommendation (stronger than amiodarone's IIb): 5

• Loading infusion: 20-30 mg/min up to maximum 10-17 mg/kg 3, 5
• Maintenance infusion: 1-4 mg/min 3
• Monitor blood pressure and ECG continuously during administration 5
• Reduce infusion rate in patients with renal dysfunction 3
• Contraindicated in patients with severe heart failure or acute infarction 3

Second-Line Alternative: Lidocaine

Lidocaine is particularly useful when VT is thought to be ischemia-related: 3, 2, 4

• Initial bolus: 1.0-1.5 mg/kg IV (maximum 100 mg) 2, 4
• Supplemental boluses: 0.5-0.75 mg/kg every 5-10 minutes to maximum total loading dose of 3 mg/kg 3, 4
• Maintenance infusion: 2-4 mg/min 3, 2, 4
• Reduce dose in elderly patients and those with heart failure or hepatic dysfunction 3
• Monitor for CNS toxicity (drowsiness, perioral numbness, confusion, seizures) 2

Special Situations

Torsades de Pointes (Polymorphic VT with Long QT)

• Administer magnesium 8 mmol (2 grams) IV bolus immediately, especially if hypomagnesemia is suspected 3, 4
• Follow with maintenance infusion of 2.5 mmol/hour 3
• Correct underlying electrolyte abnormalities (potassium, magnesium) 3, 4

VT Storm (≥3 episodes in 24 hours)

• IV beta-blockers are the single most effective therapy for polymorphic VT storm 3
• Combine amiodarone with beta-blockers as first-line therapy 3
• Consider urgent catheter ablation if refractory to medical therapy 3

Critical Contraindications and Pitfalls

Avoid calcium channel blockers (verapamil, diltiazem) entirely in VT patients, especially those with myocardial dysfunction, as they can precipitate VF or profound hypotension. 4 This is a common and dangerous error.

Do not use adenosine for unstable or irregular/polymorphic wide-complex tachycardias, as it may cause degeneration to VF. 1 Adenosine is only appropriate for regular monomorphic wide-complex tachycardias when the diagnosis is uncertain. 1

Avoid Class IC antiarrhythmics (flecainide, propafenone) in patients with prior MI or structural heart disease. 3

Practical Administration

• Always administer IV drugs with a 20 mL saline bolus to aid delivery to central circulation 2, 4
• Correct electrolyte abnormalities (potassium >4.0 mEq/L, magnesium >2.0 mg/dL) before and during therapy 3, 4
• Monitor continuously for hypotension, bradycardia, and AV block during antiarrhythmic administration 4
• Have cardioversion equipment immediately available when administering any antiarrhythmic drug 1

Evidence Considerations

While procainamide has the strongest efficacy data and highest guideline recommendation (Class IIa vs. IIb for amiodarone), amiodarone is more commonly used in practice due to its safety profile in patients with structural heart disease and heart failure. 5, 7 The choice should be guided by the specific clinical context: procainamide for patients without severe structural disease, amiodarone for those with heart failure or significant left ventricular dysfunction. 3, 5