In the Stable Tachycardia Narrow Complex with irregular rhythm, which intervention is listed first?

In the Stable Tachycardia Narrow Complex with irregular rhythm, which intervention is listed first?

• A. Immediate synchronized cardioversion
• B. Vagal maneuvers
• C. Start defibrillation
• D. Administer Amiodarone 150 mg

Answer: (B)

In stable narrow-complex tachycardias, start with noninvasive measures that can interrupt AV-node–dependent circuits. Vagal maneuvers increase parasympathetic tone and slow conduction through the AV node, which can terminate AV nodal reentry tachycardia (AVNRT) or AVRT and can reduce the ventricular rate in atrial tachyarrhythmias. This makes them the best first move when the rhythm is narrow and the patient is stable, even if the rhythm is irregular, because they’re safe to try and can convert some SVTs without medications or shocks. If vagal maneuvers don’t convert the rhythm and the patient remains stable, you’d move to pharmacologic rate or rhythm control (for example, antiarrhythmics like amiodarone), or proceed to synchronized cardioversion only if the patient becomes unstable. The other actions—defibrillation or immediate cardioversion—are reserved for unstable patients, and starting a drug like amiodarone is appropriate only after noninvasive measures have been attempted or if rhythm control is clearly indicated.

In stable narrow-complex tachycardias, start with noninvasive measures that can interrupt AV-node–dependent circuits. Vagal maneuvers increase parasympathetic tone and slow conduction through the AV node, which can terminate AV nodal reentry tachycardia (AVNRT) or AVRT and can reduce the ventricular rate in atrial tachyarrhythmias. This makes them the best first move when the rhythm is narrow and the patient is stable, even if the rhythm is irregular, because they’re safe to try and can convert some SVTs without medications or shocks.

If vagal maneuvers don’t convert the rhythm and the patient remains stable, you’d move to pharmacologic rate or rhythm control (for example, antiarrhythmics like amiodarone), or proceed to synchronized cardioversion only if the patient becomes unstable. The other actions—defibrillation or immediate cardioversion—are reserved for unstable patients, and starting a drug like amiodarone is appropriate only after noninvasive measures have been attempted or if rhythm control is clearly indicated.