The role of non-invasive blood pressure monitoring in the provocation test for patients with syncope

Syncope is a common pathological state of sudden temporary loss of consciousness which is derived from a reduction in cerebral blood flow related to a fall in blood pressure. In patients with syncope, the provocation of hypotension and syncope by stimulation of the baro-reflex is of great diagnostic value for the analysis of the reflex related mechanism as a cause of syncope. Previously, invasive blood pressure measurement was used to monitor the transient hypotension, however, the invasive approach limits the indication. Therefore, the application of a real time noninvasive blood pressure (NIBP) monitoring device in the provocation test was investigated in patients with syncope. The accuracy of real time NIBP during the Valsalva maneuver was adequate, suggesting that this device is feasible for the measurement of rapidly decreasing pressure. Syncope without organic disease was prospectively evaluated by means of carotid sinus massage (CSM) and tilt table test. CSM was positive in 15 of 72 patients (20.8%), and tilt test was positive in 17 of 68 patients (25.0%); at least one test was positive in 22 of the 57 patients (38.6%). The real-time NIBP monitor was shown to be a useful device in the provocation test of syncope.