If a patient has monomorphic ventricular tachycardia, which medication should be used first?

If a patient has monomorphic ventricular tachycardia, which medication should be used first?

• A. Adenosine
• B. Amiodarone
• C. Dopamine
• D. Norepinephrine

Answer: (B)

Monomorphic ventricular tachycardia is a wide-complex rhythm that originates in the ventricles, so the goal is to suppress the ventricular tachyarrhythmia with an antiarrhythmic that works well on ventricular tissue. Amiodarone fits this role best because it has broad antiarrhythmic effects, especially prolonging the action potential and refractory period in ventricular myocardium. This helps terminate the VT and reduce the chance of recurrence, and it can be given quickly by IV for rapid effect. It’s effective whether the patient is stable or unstable, making it the preferred first-line drug in this scenario. Adenosine, by contrast, targets the AV node to treat certain supraventricular tachycardias and is not effective for VT; using it in VT can be unsafe. Dopamine and norepinephrine are vasopressors used to support blood pressure and perfusion, not to terminate ventricular tachycardia. They do not address the underlying arrhythmia and can potentially worsen stress on the heart if used in place of an antiarrhythmic. If the patient were pulseless VT, defibrillation would be the priority, with agents like amiodarone used after resuscitation efforts. In a VT patient with a pulse, amiodarone is the appropriate first choice.

Monomorphic ventricular tachycardia is a wide-complex rhythm that originates in the ventricles, so the goal is to suppress the ventricular tachyarrhythmia with an antiarrhythmic that works well on ventricular tissue. Amiodarone fits this role best because it has broad antiarrhythmic effects, especially prolonging the action potential and refractory period in ventricular myocardium. This helps terminate the VT and reduce the chance of recurrence, and it can be given quickly by IV for rapid effect. It’s effective whether the patient is stable or unstable, making it the preferred first-line drug in this scenario.

Adenosine, by contrast, targets the AV node to treat certain supraventricular tachycardias and is not effective for VT; using it in VT can be unsafe. Dopamine and norepinephrine are vasopressors used to support blood pressure and perfusion, not to terminate ventricular tachycardia. They do not address the underlying arrhythmia and can potentially worsen stress on the heart if used in place of an antiarrhythmic.

If the patient were pulseless VT, defibrillation would be the priority, with agents like amiodarone used after resuscitation efforts. In a VT patient with a pulse, amiodarone is the appropriate first choice.