Can beta‑blockers be given in ventricular tachycardia?

Beta-Blockers in Ventricular Tachycardia

Beta-blockers can and should be given in specific types of ventricular tachycardia, particularly polymorphic VT with suspected ischemia and recurrent VT/VF storm, where they are Class I and Class IIa recommendations respectively. However, they are not first-line agents for acute termination of stable monomorphic VT.

When Beta-Blockers Are Recommended in VT

Polymorphic VT with Ischemia (Class I Indication)

• Intravenous beta-blockers are useful for patients with recurrent polymorphic VT, especially if ischemia is suspected or cannot be excluded. 1
• Beta-blockers improve mortality in the setting of recurrent polymorphic VT with acute myocardial infarction. 1
• This is a Class I recommendation with Level of Evidence B. 1

VT/VF Storm in Recent MI (Class IIa Indication)

• In patients with a recent MI who have VT/VF that repeatedly recurs despite direct current cardioversion and antiarrhythmic medications (VT/VF storm), an intravenous beta-blocker can be useful. 1
• This represents a Class IIa recommendation with Level of Evidence B-NR. 1

Repetitive Monomorphic VT (Class IIa Indication)

• Intravenous beta-blockers can be useful for treating repetitive monomorphic VT in the context of coronary disease and idiopathic VT. 1
• This is a Class IIa recommendation with Level of Evidence C. 1

When Beta-Blockers Are NOT First-Line in VT

Hemodynamically Unstable VT

• Direct-current cardioversion with appropriate sedation is recommended at any point in the treatment cascade for patients with suspected sustained monomorphic VT with hemodynamic compromise. 1
• Do not delay cardioversion to attempt pharmacologic therapy when the patient is unstable. 1

Stable Monomorphic VT (Not First-Line)

• For hemodynamically stable monomorphic VT, intravenous procainamide is the reasonable first-line agent (Class IIa). 1
• Intravenous amiodarone is reasonable for patients with sustained monomorphic VT that is hemodynamically unstable, refractory to cardioversion, or recurrent despite procainamide. 1
• Beta-blockers are not mentioned as first-line therapy for acute termination of stable monomorphic VT in the guidelines. 1

Mechanism and Rationale

Why Beta-Blockers Work in Polymorphic VT

• Polymorphic VT is frequently triggered by myocardial ischemia, and beta-blockers reduce myocardial oxygen demand by decreasing heart rate, contractility, and blood pressure. 1
• Beta-blockers suppress catecholamine-mediated triggered activity that precipitates polymorphic VT in the ischemic setting. 1

Long-Term Secondary Prevention

• Beta-blockers are the only antiarrhythmic drugs that have been demonstrated to reduce mortality in patients with VT or complex ventricular arrhythmias. 2
• Beta-blocker use was independently associated with improved survival in patients with VF or symptomatic VT who were not treated with specific antiarrhythmic therapy (adjusted RR = 0.47; 95% CI 0.25 to 0.88; p = 0.018). 3
• However, this protective effect was not prominent in patients already receiving amiodarone or an implantable cardioverter-defibrillator. 3

Critical Pitfalls to Avoid

Do Not Use in Wide-QRS Tachycardia of Unknown Origin

• Wide-QRS tachycardia should be presumed to be VT if the diagnosis is unclear. 1
• Calcium channel blockers such as verapamil and diltiazem should not be used to terminate wide-QRS-complex tachycardia of unknown origin, especially in patients with a history of myocardial dysfunction. 1
• While this contraindication is explicit for calcium-channel blockers, beta-blockers are also not recommended as first-line agents for wide-complex tachycardia of uncertain etiology. 1

Contraindications to Beta-Blockers in VT

• Do not use beta-blockers in patients with decompensated heart failure or cardiogenic shock. 1
• Avoid in severe reactive airway disease or active asthma. 1
• Do not use in second- or third-degree AV block without a pacemaker. 1

Practical Algorithm for Beta-Blocker Use in VT

Step 1: Assess hemodynamic stability

• If unstable (hypotension, altered mental status, shock, chest pain, acute heart failure) → immediate synchronized cardioversion. 1

Step 2: Determine VT morphology and context

• Polymorphic VT + suspected ischemia → IV beta-blocker (Class I). 1
• Recurrent VT/VF storm in recent MI → IV beta-blocker (Class IIa). 1
• Stable monomorphic VT → IV procainamide first (Class IIa); beta-blockers are not first-line. 1
• Repetitive monomorphic VT in coronary disease → IV beta-blocker can be useful (Class IIa). 1

Step 3: If beta-blocker is indicated, use appropriate agent

• Intravenous metoprolol 2.5–5 mg every 2–5 minutes (maximum 15 mg over 10–15 minutes). 1
• Intravenous esmolol for titratable short-term control. 1

Step 4: Long-term management

• Beta-blockers are recommended for secondary prevention of sudden cardiac death in patients with heart failure with reduced ejection fraction (LVEF ≤40%). 1
• Implantable cardioverter-defibrillator is the most effective therapy for patients with life-threatening VT or ventricular fibrillation. 2