Unexplained syncope--is screening for carotid sinus hypersensitivity indicated in all patients aged >40 years?

Abstract

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-tobeat 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.

Carotid sinus syndrome and cardiovagal regulation in elderly patients with suspected syncope-related falls

“…In our group of elderly subjects, the total variation decreased, but this reduction was evenly distributed in the whole frequency area; the shift towards low frequent variation in the tilted position was missing, in agreement with the findings by Lipsitz et al [2]. In accordance with others [25], we found OH to occur in 24% of patients with CSS, and there was a tendency for patients diagnosed with OH to have impaired HRV in the low frequency range in the tilted position.…”

“…We have also demonstrated a relatively high prevalence of CSS in a cohort of elderly people suffering from falls and syncope. High prevalence of CSS has also been demonstrated in asymptomatic elderly with no history of dizziness, syncope and falls and therefore the clinical importance of CSS diagnoses is unclear, and it has been suggested that the current criteria are too sensitive [25,28]. Wieling et al have proposed a stricter set of diagnostic criteria for CSS with cut off values of 6 s asystole for cardioinhibitory CSS and a drop in SBP of more than 75 mmHg or to values lower than 80 mmHg for vasodepressor CSS, both of which require reproduction of spontaneous symptoms [29].…”

The arterial baroreflex

“…The incidence of carotid sinus hypersensitivity increases steeply with age. 32 However, positive carotid sinus massage responses may occur in 30% of patients with Alzheimer disease and no history of syncope and are therefore not predictive of increased risk of syncope. 33 ␣-Synuclein deposits affecting the stellate ganglia, NTS, and the dorsal vagal nucleus were found at autopsy of a patient with cardioinhibitory syncope due to carotid sinus hypersensitivity.…”

Anatomy of the carotid sinus nerve and surgical implications in carotid sinus syndrome

“…5 Pacemaker implantation is considered the treatment of choice for cardioinhibitory CSS, but is not effective in vasodepressor CSS. 6,7 Especially in the latter type, one may opt for interrupting the pathological baroreceptor reflex using a variety of surgical approaches. A recent review evaluating adventitial stripping of the carotid sinus in 110 CSS patients demonstrated an excellent short-and long-term clinical response.…”