Carotid sinus syncope
A form of neurogenic syncope induced by external pressure over the carotid sinus. It can be:
The baroreceptive or mixed forms which makes up well over 60% of cases can only be diagnosed by continuous blood pressure monitoring, preferably noninvasively and often is only symptomatic in the erect position. This is safest when undertaken as part of a tilt table study.
The current recommendations for diagnosis of carotid sinus syndrome (ESC) are on up to 10 seconds unilateral carotid massage:
- Greater than 6 seconds asystole (Used to be 3 seconds) and/or
- Greater than 50mmHg fall in systolic BP
- Reproduction of symptoms (eg syncope)
- This is usually only possible on tilting
Carotid sinus hypersensitivity is either of the first two above
This patient had a 15 year history of syncope and partial syncope, more recently with injury and much more severe syncope with prolonged recovery and no warning as in the past. Vaso-vagal (neurogenic) syncope was suspected from history. The specific left carotid hypersensitivity is shown and this was cardioinhibitory with a 22 second period of ventricular asystole. It explained his recent sudden faints which could have been associated with head movements by history. Also explained was the long history of syncope without injury and good recovery. Pure baroreceptive mediated neurogenic pre-syncope occurred when ever he tried to sit up for 20 minutes although the response gradually got blunter. The patient felt fully recovered about 30 minutes after the syncope. Treatment was with a pacemaker.
- ↑ Claesson JE, Kristensson BE, Edvardsson N, Währborg P. Less syncope and milder symptoms in patients treated with pacing for induced cardioinhibitory carotid sinus syndrome: a randomized study. Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. 2007 Oct; 9(10):932-6.(Link to article – subscription may be required.)