Vagal Maneuvers: How to Stop Your Patient's SVT
Vagal maneuvers are used in the clinical setting to slow down fast heart rates — primarily supraventricular tachycardia (SVT), and sometimes rapid atrial fibrillation (AF with RVR).
There are several physical maneuvers that can slow the heart rate — and there's an important modified technique that can almost triple your chances of success.
SVT and Vagal Maneuvers
Supraventricular Tachycardia (SVT) is a very rapid, regular arrhythmia caused by a reentrant loop within the heart. Essentially, the signal goes around and around in a circuit, producing very fast heart rates.
While SVT is an umbrella term for any tachycardia originating above the ventricles, it usually refers to AV Nodal Reentrant Tachycardia (AVNRT) — a reentrant loop within or near the AV node itself. Some patients have abnormal conduction tissue in this area, and if a premature beat arrives at the wrong time, it can throw them into this very fast rhythm.
We want to stop or "break" this rhythm as soon as possible so the patient doesn't decompensate. On the Adult Tachycardia ACLS algorithm, the first step to stop SVT in a stable patient is vagal maneuvers.
The Vagus Nerve and the Heart
To understand vagal maneuvers, you first need to understand how the vagus nerve works. The vagus nerve is the primary way the parasympathetic nervous system affects the body. It's the 10th cranial nerve, traveling from the brain throughout the body to control automatic functions.
Stimulating the vagus nerve slows conduction and increases the refractory period of the AV node, which hopefully breaks the SVT reentrant loop and converts the patient back to normal sinus rhythm (NSR).
Some everyday actions stimulate the vagus nerve — coughing, vomiting, and cold-water immersion. In the hospital, we perform deliberate "vagal maneuvers" to intentionally cause a vagal response and slow a tachyarrhythmia like SVT. The two main ones are the Valsalva maneuver and the carotid sinus massage.
The Modified Valsalva Maneuver
The Valsalva maneuver is the classic way to stimulate the vagus nerve and stop SVT. It's used on patients who are stable (stable vital signs) and can follow commands. To perform it, the patient intentionally "bears down" or strains for 10–15 seconds.
The standard Valsalva has a 17% success rate in converting SVT. By modifying it, we almost triple that. The Modified (positional) Valsalva has a significantly higher success rate of 43% — almost half of SVT patients can convert back to NSR without any medications or further interventions.
Have a physician or APP present before starting.
Place the patient at 45° (semi-Fowler's).
Have the patient breathe in normally.
Have them forcefully exhale against a closed glottis (bearing down) for 15 seconds.
Immediately place them supine and raise their legs to 45° for 15 seconds.
Return to semi-Fowler's and watch for up to 1 minute for resolution of the SVT.
Clinical Tip
If the patient has trouble bearing down, place an empty 10-mL syringe in their mouth and have them blow hard enough to make the plunger move.
This technique takes a few assistants, but it's clearly the better option when attempting to convert SVT with vagal maneuvers.
The Carotid Sinus Massage
The carotid sinus massage is a vagal maneuver you can perform on someone who cannot follow commands. The carotid sinus is located just below the internal carotid artery at the level of the thyroid cartilage, near the pulse. This area is very sensitive to mechanical pressure, and pressure here can stimulate the vagus nerve.
Place them supine with the neck extended toward the opposite side.
Ensure there is no carotid bruit with your stethoscope.
Inferior to the angle of the mandible, at the level of the thyroid cartilage, near the pulse.
Apply firm pressure for 5–10 seconds.
You can repeat on the other side if needed — but never both sides at once.
Never Perform Carotid Massage If…
Without a physician/APP at the bedside; on both sides simultaneously; in someone with TIA or stroke within the last 3 months; or in someone with known carotid stenosis or an active carotid bruit.
Complications of Vagal Maneuvers
Side effects from vagal maneuvers are usually short-lived and an "over-exaggeration" of the expected effects. These include sinus pauses, brief asystole, bradycardia, AV blocks, and hypotension — most of which resolve on their own within seconds to minutes.
Clinical Pearls
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Related Guides
References
- Frisch DR, Zimetbaum PJ. Vagal maneuvers. UpToDate.
- Knight BP. Atrioventricular nodal reentrant tachycardia. UpToDate.
- Burns E. Supraventricular tachycardia. LITFL ECG Library.
- Aehlert BJ. ECGs Made Easy (6th ed.). Elsevier Health Sciences.
- Grauer K. ECG Pocket Brain: Expanded Version (6th ed., pp. 65–68). KG/EKG Press.
- Tintinalli JE, Brady WJ, Laughrey TS, Ghaemmaghami CA. Cardiac Rhythm Disturbances. In Tintinalli's Emergency Medicine: A Comprehensive Study Guide (8th ed., p. 126). McGraw-Hill Education.
Thank y.very very very much
Tried all the maneuvers out there this is the only one that works. Thank you!!!!
Thank you for creating instructions with illustrations.