The Diagnostic Value of the Treadmill Exercise Test Combined with the Head Up Tilt Test for Diagnosing Vasovagal Syncope

Objective: Increased adrenergic tone can be a trigger of orthostatic stress of vasovagal syncope (VVS). This study aimed to explore the diagnostic value of treadmill exercise test (TET) combined with head up tilt test (HUTT) for VVS. Methods: A total of 73 patients with unexplained syncope or presyncope were enrolled. VVS was diagnosed in 57 patients according to the Calgary Score (≥-2). Initially, all patients were subjected to the first HUTT. Then, patients with negative response in HUTT would further received TET on the next day. At last, patients who remained getting negative response in TET would be subjected to the second HUTT within 10min after TET. The symptoms of syncope, heart rate and blood pressure were recorded during the tests. Results: Syncope or presyncope occurred in 34 patients in the first HUTT. The sensitivity and specificity of HUTT for Calgary score-based VVS were 56.1% and 87.5%, respectively. Then, another 14 patients in TET and 9 patients in the second HUTT experienced syncope or presyncope during the tests. The sensitivity of TET combined with HUTT for VVS significantly increased to 94.7%, with the specificity only slightly decreasing to 81.3%. No patients required anticholinergics injection to restore vital signs during the tests. Conclusion: The combination of TET with HUTT is an effective and safe diagnostic strategy for VVS.