Q&A: Carotid Sinus Massage

Carotid sinus massage, or simply carotid massage, is a simple bedside manoeuvre that helps to clarify the type and sometimes also the mechanism of different heart rhythm disturbances. Only a competent doctor should do this as there are inherent risks which need to be borne in mind.

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In this article:
What is carotid sinus massage
MCQ exam: clinical scenario
MCQ exam: answer
MCQ exam: explanation

What is carotid sinus massage

Carotid massage involves gently massaging the carotid artery for 5-10 seconds on one side of the neck whilst monitoring the heart rhythm and blood pressure. Cardiac rhythm is monitored via continuous ECG (sticky pads on the chest attached to a heart monitor) and blood pressure monitoring. If the test is normal on one side of the neck, it will probably be repeated on the other side.

Carotid sinus massage is a procedure that is used to investigate unexplained dizziness, falls or faints where they are suspected to be due to heart rhythm problems. The major indication is for diagnosis of tachyarrhythmias in which the atrial activity is either absent or intermittently present. Carotid sinus massage is also useful in some patients with normal heart rates; increased vagal tone may normalize a bundle branch block or localize the site of type I second-degree atrioventricular block and can be used for evaluation of the sensing function of permanent pacemakers. Carotid sinus massage is also an important diagnostic procedure in patients with suspected hypersensitivity of the carotid sinus.

Massage of the carotid sinus is contraindicated in patients with diseased carotid arteries because of the risk of cerebrovascular accident. In rare instances, carotid sinus massage may initiate ventricular tachycardia.

MCQ exam: clinical scenario

A patient develops syncope on head turning.

The physician decides to perform carotid massage and is giving instructions to his senior registrar on how to perform the carotid massage.

Which of the following is a valid instruction for carotid massage in this patient:

a) Start with carotid sinus on left side
b) Never massage both carotids simultaneously
c) A Carotid Bruit is a definite contraindication
d) The patient should be sitting up for the procedure
e) Patient should stand for 5 minutes prior to massage

MCQ exam: answer

The correct answer is B.
Never massage both carotids simultaneously.

MCQ exam: explanation

The carotid sinus is a small bundle of nerve endings situated next to the carotid arteries in the neck. There are 2 carotid arteries, one on each side of the neck, which provide the main blood supply to the brain and scalp. There is a carotid sinus on each side of the neck situated where the carotid artery separates into two (roughly just below the ears). The carotid sinus has chemical and pressure receptors that provide information to the brain on blood flow and blood pressure. This helps the body maintain a controlled supply of blood to its organs including the brain, the heart and the muscles.

When external pressure is placed on the carotid sinus it automatically reduces the heart rate, normally only by a small amount. In some people, though, the carotid sinus overreacts to such pressure causing their heart rate to slow down or their blood pressure to drop a significant amount. This overreaction is called carotid sinus hypersensitivity. Any pressure on the artery may cause this reaction, including wearing tight clothing around the neck or even turning the head. When hypersensitivity is accompanied by a brief blackout that results in a fall it is known as carotid sinus syndrome.

While investigating unexplained dizziness, falls or faints; a carotid sinus massage may be carried out. A positive test would result in a reproduction of the dizziness or a blackout (causing falls or faints), and a drop in the heart rate and/or blood pressure. Both carotids should be confirmed to be pulsatile in advance before the massage is done. Auscultation of the carotid arteries is also essential before the massage test can be considered. A carotid bruit is a relative contra-indication and a carotid ultrasound must be performed to further evaluate any patient who is found to have a carotid bruit. Never massage both carotids simultaneously!

Reference(s)
1). The American Journal of Medicine: Carotid sinus massage. Its diagnostic and therapeutic value in arrhythmias. Available online: https://www.amjmed.com/article/0002-9343(85)90408-5/pdf
2). County Durham and Darlington NHS Foundation Trust (CDDFT): Carotid Sinus Hypersensitivity . Available online: https://www.cddft.nhs.uk/media/44337/carotidsinushypersensitivity.pdf
3). Royal United Hospital Bath NHS Trust: Carotid Sinus Massage. Available online: https://www.ruh.nhs.uk/patients/services/clinical_depts/older_people/documents/Carotid_Sinus_Massage.pdf