BACKGROUND: Syncope due to carotid sinus hypersensitivity (CSH) may be underdiagnosed due to a low level of diagnostic suspicion and fear of complications caused by massage of the carotid sinus. OBJECTIVE: To investigate the relevance of carotid sinus massage in the diagnosis of non-convulsive faints and unexplained falls. METHODS: Two-hundred and fifty-nine patients with a mean age of 50±24 years referred for the investigation of non-convulsive faints or unexplained falls were evaluated with a head up tilt table test (HUTT) without ("passive") and with pharmacological stimulation. Clinical and laboratory work-up did not reveal an obvious cause for the complaints. Fifty-five volunteers with a mean age of 57±21 years with no history of seizures, faints or falls were used as controls. All participants underwent a HUTT preceded by digital stimulation of each carotid sinus both at zero and 60º. RESULTS: Carotid sinus massage was positive in 4 controls. The relevance of CSH in the evaluation of syncope was supported by a positive response to carotid sinus massage at 60º in 28 patients, most of whom were elderly men. Carotid sinus massage was positive at 0º in only three of such patients. The results of the HUTT did not show statistical difference between patients with and without CSH. CONCLUSION: Carotid sinus massage at 60º under controlled conditions should be included in the assessment of patients with non-convulsive faints or unexplained falls. Routine cardiovascular exams, including the HUTT, are not useful for the diagnosis in such cases. Further studies in normal individuals are needed to establish the significance of a positive response to carotid sinus massage in the absence of a history of fainting or falling.
Syncope; hypersensitivity; carotid sinus; tilt table test
