In an adult with stable supraventricular tachycardia, what is the first-line management?

In an adult with stable supraventricular tachycardia, what is the first-line management?

• A. Adenosine: 12 mg rapid IV push
• B. Vagal maneuvers
• C. Cardizem: 10 mg IV/IO and then 15 mg IV/IO
• D. Synchronized cardiovert: 150 J then 200 J

Answer: (B)

When a patient with stable supraventricular tachycardia is found to be hemodynamically stable, the first step is nonpharmacologic vagal maneuvers. These techniques increase parasympathetic input to the heart and slow conduction through the AV node, which can interrupt the reentrant circuit responsible for many SVTs and restore a normal rhythm. Examples include the Valsalva maneuver or other bearing-down actions, coughing, or immersion in cold water. Carotid sinus massage is sometimes used but only by experienced personnel and with caution due to stroke risk in some patients. If vagal maneuvers fail to terminate the tachycardia and the patient remains stable, pharmacologic therapy is pursued next, typically starting with adenosine because it transiently blocks AV nodal conduction and can quickly terminate AV node–dependent SVTs. If adenosine is contraindicated or ineffective, other antiarrhythmics like calcium channel blockers (for example, diltiazem) may be used. Synchronized cardioversion is reserved for unstable patients who do not tolerate the tachycardia or show signs of poor perfusion.

When a patient with stable supraventricular tachycardia is found to be hemodynamically stable, the first step is nonpharmacologic vagal maneuvers. These techniques increase parasympathetic input to the heart and slow conduction through the AV node, which can interrupt the reentrant circuit responsible for many SVTs and restore a normal rhythm. Examples include the Valsalva maneuver or other bearing-down actions, coughing, or immersion in cold water. Carotid sinus massage is sometimes used but only by experienced personnel and with caution due to stroke risk in some patients.

If vagal maneuvers fail to terminate the tachycardia and the patient remains stable, pharmacologic therapy is pursued next, typically starting with adenosine because it transiently blocks AV nodal conduction and can quickly terminate AV node–dependent SVTs. If adenosine is contraindicated or ineffective, other antiarrhythmics like calcium channel blockers (for example, diltiazem) may be used. Synchronized cardioversion is reserved for unstable patients who do not tolerate the tachycardia or show signs of poor perfusion.