Diagnostic efficacy and prognostic evaluation value of QT interval dispersion in children and adolescents with cardioinhibitory vasovagal syncope / 中国小儿急救医学

ABSTRACT

Objective:To study the diagnostic efficacy and prognostic evaluation value of QT interval dispersion (QTd) in children and adolescents with cardioinhibitory vasovagal syncope (VVS-CI).Methods:From July 2010 to January 2020, 80 children and adolescents who received their first visit or admission to the Pediatric Syncope Clinic of The Second Xiangya Hospital of Central South University and definite diagnosed of VVS-CI due to syncope or presyncope were selected as the VVS-CI group, meanwhile, 80 children and adolescents who had physical examination in the hospital were selected as the control group.QT interval were measured by 12-lead electrocardiogram at the baseline.Results:(1) Comparison between the two groups Compared with the control group, the VVS-CI group had a significantly lower heart rate ( P<0.05) and significantly longer QT interval, such as the maximum QT interval (QTmax), minimum QT interval (QTmin), QTd, corrected maximum QT interval (QTcmax) and corrected QT interval dispersion (QTcd) ( P<0.05). After follow-up 84 (45, 127) days, compared with the responsive group, the non-responsive group had a significantly longer QT interval, such as QTmax, QTd, QTcmax, corrected minimum QT interval (QTcmin)and QTcd ( P<0.05). (2) Diagnostic efficiency QTmax, QTmin, QTd, QTcmax and QTcd had a certain diagnostic value in children and adolescents with VVS-CI ( P<0.001). QTd had the largest area under the curve (AUC) (0.914), and had a sensitivity of 86.30% and a specificity of 84.95% at the optimal cut-off value of 28.50 ms for VVS-CI diagnosis.(3) Prognostic evaluation value QTmax, QTd, QTcmax, QTcmin, QTcd had an estimated value for the prognosis of VVS-CI in children and adolescents ( P<0.05 or 0.01). QTd had the largest AUC (0.906) and the best cut-off value was 34.50 ms, the sensitivity to predict response to VVS-CI intervention was 90.00%, and the specificity was 82.35%. Conclusion:QTd of electrocardiogram has a good estimation value in the diagnosis and prognosis of VVS-CI in children and adolescents.