Which medication is used IV for SVT if non-pharmacologic maneuvers fail?

Which medication is used IV for SVT if non-pharmacologic maneuvers fail?

• A. Atropine
• B. Adenosine
• C. Amiodarone
• D. Lidocaine

Answer: (B)

When nonpharmacologic maneuvers fail to terminate a narrow-complex SVT, the IV medication of choice is adenosine. It works by briefly blocking conduction through the AV node, which is where many SVTs rely on a reentrant circuit. By momentarily interrupting AV nodal conduction, adenosine often terminates the tachycardia and returns the heart to a normal rhythm. Adenosine acts extremely quickly and has a very short half-life, so the effect is transient. Patients may experience a fleeting pause in rhythm, along with sensations like chest flushing or brief chest discomfort, but these effects wear off within seconds to a minute. Because of its rapid onset and short duration, it’s given as a rapid IV push with a saline flush, typically starting with a 6 mg dose and repeating with 12 mg if there’s no response. Other drugs you might consider in different scenarios include atropine, which is used for bradycardia rather than SVT, and amiodarone or lidocaine, which are geared more toward ventricular arrhythmias or refractory cases rather than first-line treatment for SVT.

When nonpharmacologic maneuvers fail to terminate a narrow-complex SVT, the IV medication of choice is adenosine. It works by briefly blocking conduction through the AV node, which is where many SVTs rely on a reentrant circuit. By momentarily interrupting AV nodal conduction, adenosine often terminates the tachycardia and returns the heart to a normal rhythm.

Adenosine acts extremely quickly and has a very short half-life, so the effect is transient. Patients may experience a fleeting pause in rhythm, along with sensations like chest flushing or brief chest discomfort, but these effects wear off within seconds to a minute. Because of its rapid onset and short duration, it’s given as a rapid IV push with a saline flush, typically starting with a 6 mg dose and repeating with 12 mg if there’s no response.

Other drugs you might consider in different scenarios include atropine, which is used for bradycardia rather than SVT, and amiodarone or lidocaine, which are geared more toward ventricular arrhythmias or refractory cases rather than first-line treatment for SVT.