Is diltiazem (calcium channel blocker) 60 mg okay for ventricular tachycardia (VTach)?

Diltiazem Should NOT Be Used for Ventricular Tachycardia

Diltiazem 60 mg is contraindicated for ventricular tachycardia (VTach) and should never be used for this condition. 1, 2

Why Diltiazem is Contraindicated in VTach

• Calcium channel blockers such as diltiazem are specifically contraindicated in patients with ventricular tachycardia (Class III recommendation, Level of Evidence C) 1
• The FDA label explicitly states that diltiazem is contraindicated in patients with ventricular tachycardia 2
• Administration of calcium channel blockers to patients with wide complex tachycardia has resulted in hemodynamic deterioration and ventricular fibrillation 2

Recommended Treatments for Ventricular Tachycardia

For Hemodynamically Unstable VTach:

• Direct-current cardioversion with appropriate sedation is the recommended first-line treatment (Class I, Level of Evidence C) 1
• Urgent intervention is required for unstable patients 1

For Stable Monomorphic VTach:

• Intravenous procainamide is reasonable for initial treatment (Class IIa, Level of Evidence B) 1
• Intravenous amiodarone is reasonable for patients with VTach that is hemodynamically unstable, refractory to conversion with countershock, or recurrent despite procainamide or other agents (Class IIa, Level of Evidence C) 1
• Lidocaine might be reasonable for initial treatment of patients with stable sustained monomorphic VT specifically associated with acute myocardial ischemia or infarction (Class IIb, Level of Evidence C) 1

For Polymorphic VTach:

• Direct current cardioversion with appropriate sedation is recommended for patients with hemodynamic compromise (Class I, Level of Evidence B) 1
• Intravenous beta blockers are useful, especially if ischemia is suspected (Class I, Level of Evidence B) 1
• Intravenous amiodarone is useful for recurrent polymorphic VT in the absence of abnormal repolarization related to long QT syndrome (Class I, Level of Evidence C) 1

Important Distinctions

• Diltiazem is indicated for supraventricular tachycardias (SVT) and atrial fibrillation/flutter rate control, not ventricular tachycardia 1, 3
• For SVT, diltiazem is dosed at 0.25 mg/kg IV bolus over 2 minutes, with the option to increase to a maintenance infusion at 5-15 mg/h 3
• It's critical to accurately distinguish wide complex QRS tachycardia of supraventricular origin from ventricular origin prior to administration of diltiazem 2

Common Pitfalls to Avoid

• Mistaking ventricular tachycardia for supraventricular tachycardia with aberrancy can lead to inappropriate treatment with calcium channel blockers 1, 2
• If the diagnosis is unclear, wide-QRS tachycardia should be presumed to be VT (Class I, Level of Evidence C) 1
• Verapamil (another calcium channel blocker) is similarly contraindicated for wide-complex tachycardias unless known to be of supraventricular origin (Class III, LOE B) 1

Conclusion

Diltiazem 60 mg should never be used to treat ventricular tachycardia. Using calcium channel blockers in VTach can cause hemodynamic deterioration and potentially fatal ventricular fibrillation. Appropriate treatments include cardioversion for unstable patients and specific antiarrhythmic medications (procainamide, amiodarone, or lidocaine) for stable patients.