Abstract
BACKGROUND: Vasovagal syncope (VVS) is a prevalent medical condition with a lack of efficient methods for its detection. AIM: This study aimed to explore an objective clinical indicator in diagnosing VVS. METHODS: The retrospective analysis involved clinical data of 243 syncope patients from 1 June 2020 to 31 July 2023. Among them, 108 patients had a negative result in the tilt test (TTT), while the remaining 135 patients had a positive result in the TTT. Relevant statistical methods were utilized to examine the correlation between VVS and different indicators of heart rate variability. RESULTS: After screening, 354 patients being considered for VVS were evaluated, resulting in a final sample size of 243. Sex, age, deceleration capacity (DC), and standard deviation of all normal-to-normal intervals (SDNNs) were the variables that showed statistical significance between the TTT(-) group and the TTT(+) group. Independent risk factors identified by multivariate logistic regression were DC [odds ratio (OR) 1.710, 95% confidence interval (CI) 1.388-2.106, P < 0.001] and SDNN (OR 1.033, 95% CI 1.018-1.049, P < 0.001). Comparing the groups, receiver operating characteristic analysis revealed a notable distinction in both DC and SDNN [the respective areas under the curve were 0.789 (95% CI 0.730-0.848) and 0.702 (95% CI 0.637-0.767); the cutoff values were 7.15 and 131.42; P < 0.001, respectively]. CONCLUSION: In summary, DC can function as an impartial and easily accessible clinical marker for differentiating VVS. A value exceeding 7.15 ms might suggest a higher likelihood of syncope.