title: Carotid sinus syndrome in an unselected population of eight hundred consecutive patients with syncope. Prevalence and clinical profile.
abstract: Carotid sinus syndrome (CSS) is frequently underdiagnosed in patients with unexplained syncope or falls. The goal of our study was to assess the value of carotid sinus massage (CSM) in an unselected population with syncope, in the supine position and after prolonged orthostasis. We observed 824 consecutive patients with unexplained syncope referred to our Autonomic Laboratory between October and October 2000 (36 months). For the analysis we studied only patients aged over 42 years (the age of the youngest patient with CSS). One hundred and eight normal healthy subjects served as the control group. CSM was performed after beat-by-beat blood pressure and continuous electrocardiographic monitoring, during supine rest and after prolonged (45 min) orthostasis on a motor-driven tilt table (HTT). Three hundred and eighty-six patients were selected (all more than 42 years old and with unexplained syncope). Six of them were excluded because of contraindication to CSM. Seventy-five patients (20%) had CSS (28% cardioinhibitory type, 22% pure vasodepressor response and 50% mixed type). Forty patients had CSS diagnosed in the supine position and 35 only after HTT. The response type was similar in both positions. The control group had only one positive response after HTT. CSS was more prevalent in males (66/9). We concluded that in an elderly population CSS is a frequent cause of syncope or unexplained falls, particularly in men. CSM in the supine position is 100% specific but only 53% sensitive. Syncope centers should perform CSM with continuous blood pressure monitoring and after prolonged orthostasis.
authors.affiliation: Centro de Estudos da Função Autonómica do Hospital de Sáo João, Porto, Portugal. jfreitas@netcabo.pt
authors.forename: João
authors.initials: J
authors.lastname: Freitas
authors.forename: Rosa
authors.initials: R
authors.lastname: Santos
authors.forename: Elsa
authors.initials: E
authors.lastname: Azevedo
authors.forename: Mário
authors.initials: M
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D002340:Carotid Artery Diseases / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D002346:Carotid Sinus; D006801:Humans; D015995:Prevalence; D013575:Syncope / Q000209:etiology*