Unexplained syncope—is screening for carotid sinus hypersensitivity indicated in all patients aged >40 years?
- Neurovascular Medicine Unit, Imperial College London at St Mary’s Hospital; Autonomic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
- Correspondence to: A M Humm Department of Neurology, Inselspital, CH-3010 Bern, Switzerland;
- Received 17 March 2006
- Accepted 19 May 2006
- Revised 15 May 2006
- Published Online First 30 May 2006
Objective: To determine the frequency, age distribution and clinical presentation of carotid sinus hypersensitivity (CSH) among 373 patients (age range 15–92 years) referred to two autonomic referral centres during a 10-year period.
Methods: Carotid sinus massage (CSM) was performed both supine and during 60° head-up tilt. Beat-to-beat blood pressure, heart rate and a three-lead electrocardiography were recorded continuously. CSH was classified as cardioinhibitory (asystole ⩾3 s), vasodepressor (systolic blood pressure fall ⩾50 mm Hg) or mixed. All patients additionally underwent autonomic screening tests for orthostatic hypotension and autonomic failure.
Results: CSH was observed in 13.7% of all patients. The diagnostic yield of CSM was nil in patients aged <50 years (n = 65), 2.4% in those aged 50–59 years (n = 82), 9.1% in those aged 60–69 years (n = 77), 20.7% in those aged 70–79 years (n = 92) and reached 40.4% in those >80 years (n = 57). Syncope was the leading clinical symptom in 62.8%. In 27.4% of patients falls without definite loss of consciousness was the main clinical symptom. Mild and mainly systolic orthostatic hypotension was recorded in 17.6%; evidence of sympathetic or parasympathetic dysfunction was found in none.
Conclusions: CSH was confirmed in patients >50 years, the incidence steeply increasing with age. The current European Society of Cardiology guidelines that recommend testing for CSH in all patients >40 years with syncope of unknown aetiology may need reconsideration. Orthostatic hypotension was noted in some patients with CSH, but evidence of sympathetic or parasympathetic failure was not found in any of them.
- CSH, carotid sinus hypersensitivity
- CSM, carotid sinus massage
- CSS, carotid sinus syndrome
- ECG, electrocardiography
- ESC, European Society of Cardiology
Published Online First 30 May 2006
Competing interests: None.
Ethics approval: The analysis of patient’s data for this study was approved by the Joint Research Ethics Committee of the National Hospital for Neurology and Neurosurgery and the Institute of Neurology (main REC reference number 04/Q0505/70).