Tilt Test Duration in Suspected Vasovagal Syncope: Temporal Patterns and Diagnostic Yield in Patients From Central China

Objective: The head-up tilt test (HUTT) diagnoses Vasovagal Syncope (VVS) but its duration limits adoption. We evaluated a shortened HUTT protocol in patients from Central China. Methods and Results: We retrospectively analyzed 614 patients (median age 53.5 years, 53.2% female) with suspected VVS. All underwent a standardized HUTT with a 10 min passive phase at 70°, followed, if negative, by a 15 min active phase with 0.5 mg sublingual nitroglycerin. The overall positivity rate was 60.91% (374/614), with the vast majority (359/374) of positive responses occurring during the active phase. The median positive response time was 10 min (IQR: 6.5–10) for the passive phase and 3 min (IQR: 2–5min) for the active phase, with peak incidences observed at these intervals. The positivity rates for the 10 min and 15 min active phases were 58.63% and 60.91%, respectively, with no statistically significant difference (p = 0.449). Through generalized additive model (GAM) analysis with inflection point detection, a significant nonlinear relationship between time and positivity was identified (EDF = 2.302, p < 0.001). Independent predictors of a positive test included female gender, increasing age, prior syncope before HUTT, and lower systolic blood pressure at 10 min of the passive phase. Conclusion: Our shortened HUTT protocol achieved comparable diagnostic yield in these patients while reducing test duration. Compared with the consensus-recommended protocol, the shortened HUTT protocol saved at least 37.5% of the total test time, while achieving a positive rate (60.91%).