Diagnostic efficacy of transcranial Doppler combined with upright tilt test in vasovagal syncope

BACKGROUND: Vasovagal syncope (VVS) is the most common subtype of syncope, and it significantly impacts patients' quality of life and incurs substantial healthcare costs. Although the head-up tilt table test (HUTT) is the gold standard method for diagnosing VVS, its sensitivity and specificity are limited, which leads to diagnostic challenges. Combining HUTT with transcranial Doppler (TCD) can improve diagnostic accuracy by addressing limitations in monitoring cerebral blood flow during syncope evaluation. In this study, we aimed to analyze the diagnostic efficacy of combining the HUTT and TCD in patients with VVS. METHODS: In this prospective study, we enrolled 102 patients with suspected VVS who underwent combined HUTT and TCD evaluation. The diagnostic performance of the combined approach was compared to that of the standalone HUTT, with a focus on sensitivity, specificity, and accuracy. RESULTS: The multimodal testing group showed a 25.61% increase in sensitivity for diagnosing VVS compared to the standalone HUTT group, albeit with a 10.00% reduction in specificity. The false-negative rate decreased by 25.61%, while the false-positive rate increased by 10.00%. Furthermore, the positive likelihood ratio increased by 0.151, and the negative likelihood ratio decreased by 0.3701. The overall accuracy increased by 7.8%. Notably, the areas under the curve for systolic and mean cerebral blood flow velocities were 0.717 and 0.744, respectively. CONCLUSIONS: The combination of HUTT and TCD significantly enhanced the diagnostic efficacy in patients with VVS, improving the prediction of syncope and reducing the risks associated with testing.