Which of the following are examples of vagal maneuvers used to terminate SVT?

• A. Deep breathing, leg raises
• B. Administer IV fluids only
• C. Perform defibrillation
• D. Valsalva maneuver, coughing, carotid massage

Answer: (D)

Vagal maneuvers work by stimulating the vagus nerve to slow conduction through the AV node, which can interrupt a reentrant circuit causing SVT. The classic examples—Valsalva maneuver, coughing, and carotid massage—initiate this parasympathetic effect to reduce AV nodal conduction and potentially terminate the tachycardia in stable patients. Valsalva involves bearing down to increase intrathoracic pressure; coughing similarly creates a vagal surge; carotid massage, performed by a trained clinician, directly stimulates baroreceptors to enhance vagal tone.

Other options don’t produce the intended vagal effect. Deep breathing and leg raises aren’t standard, reliable vagal maneuvers for terminating SVT. Administering IV fluids alone helps with volume status but doesn’t address AV nodal conduction. Defibrillation is a shock therapy used for non-sinus rhythms like ventricular fibrillation or unstable tachyarrhythmias, not a vagal maneuver for SVT termination.