How should carotid sinus massage be performed on an awake, spontaneously breathing adult with documented narrow‑complex supraventricular tachycardia and no contraindications such as carotid artery stenosis, recent stroke or transient ischemic attack, carotid plaque, severe aortic stenosis, uncontrolled hypertension, or unexplained syncope?

How to Perform Carotid Sinus Massage

Carotid sinus massage should be performed by applying steady pressure over the right or left carotid sinus for 5 to 10 seconds after confirming the absence of a carotid bruit by auscultation, with the patient in the supine position and continuous ECG and blood pressure monitoring. 1

Pre-Procedure Requirements

Mandatory Safety Check

• Auscultate both carotid arteries to confirm absence of bruits before proceeding 1, 2
• Ensure continuous ECG monitoring and blood pressure measurement are in place 1, 3
• Have at least two persons present during the procedure 3

Patient Positioning

• Position the patient supine first 1
• The maneuver can also be performed in the upright position after supine attempt 1, 3

Step-by-Step Technique

Locating the Carotid Sinus

• Turn the patient's head slightly contralaterally and posteriorly 3
• Palpate to identify the carotid sinus location at the level of the upper border of the thyroid cartilage 3

Performing the Massage

• Apply steady, firm pressure over the carotid sinus for a minimum of 5 seconds and maximum of 10 seconds 1
• Massage one side at a time—never massage both carotids simultaneously 1
• If the first side is unsuccessful, allow adequate time interval before attempting the contralateral side 3

Monitoring During the Procedure

• Continuously monitor heart rate and blood pressure throughout the massage 1, 3
• Observe for rhythm conversion or symptomatic response 1

Clinical Context and Efficacy

Effectiveness Considerations

While carotid sinus massage is a Class I recommendation from the ACC/AHA/HRS guidelines 1, its efficacy is modest, terminating SVT in only approximately 20-27.7% of cases 4, 5. The Valsalva maneuver has demonstrated superior efficacy (43% success rate) and should generally be attempted first 2, 5.

When CSM is Most Appropriate

• As a first-line vagal maneuver when Valsalva has failed 1
• In patients over 40 years with syncope of unknown etiology for diagnostic purposes 1
• When the patient cannot adequately perform a Valsalva maneuver 1

Critical Safety Considerations

Neurological Complications

Carotid sinus massage carries a 0.2-1% risk of potentially devastating neurological complications, including stroke 4, 6, 5. The European Heart Journal reports complication rates of 0.28-0.45% in large series 1. These complications occur from dislodgement of atherosclerotic plaque 4, 6.

Common Pitfalls to Avoid

• Never perform eyeball pressure—this technique has been abandoned due to danger 1
• Do not massage both carotids simultaneously 1
• Do not exceed 10 seconds of massage duration 1
• Avoid in elderly patients with high atherosclerotic risk where safer alternatives exist 6, 5

Self-Limited Expected Responses

• Transient asystole induced by massage is self-terminating and typically requires no resuscitative measures 1
• Rarely, self-limited atrial fibrillation may occur with little clinical significance 1

Alternative Approaches

Given the modest efficacy and potential neurological risks, consider the modified Valsalva maneuver as the preferred first-line vagal intervention 2, 7, 5. If vagal maneuvers fail, adenosine 6 mg IV rapid push achieves approximately 95% termination rate for AVNRT 1, 2.