A study of carotid sinus massage and head-up tilt table testing in patients with syncope and near-syncope.

Patients with syncope of unknown origin are commonly evaluated using several diagnostic tools. It has been suggested that there is a significant overlap between the results of head-up tilt table testing (HUT) and carotid sinus massage (CSM). We retrospectively studied the association between tilt table test results and CSM outcome in 136 patients with syncope or near-syncope who underwent both tests. Carotid sinus massage was performed prior to the tilt test, with the patient supine. The patient was then tilted to 60 degrees for up to 30 minutes. If this did not elicit a symptomatic abnormal hemodynamic response, the tilt was repeated for up to 30 minutes with intravenous isoproterenol. An abnormal response on HUT was elicited in 18% of patients and carotid sinus syndrome was diagnosed in 13%. Mild carotid sinus sensitivity was seen in 14%. Both tests were positive in 4 patients (3%; 11% of patients with a positive test). There was no significant relationship between HUT outcome and CSM result (p = 0.03). Patients with an abnormal CSM result were older (p < 0.001) and more likely to have prior cardiovascular diagnoses (p = 0.01). The opposite applied to patients with abnormal HUT (p = 0.02 and p = 0.0048, respectively). In conclusion, we did not find a concordance between HUT and CSM outcomes in patients with syncope or near-syncope of undetermined origin.