Differential diagnostic value of P wave dispersion and QT interval dispersion between psychogenic pseudosyncope and vasovagal syncope in children and adolescents

Background: Both psychogenic pseudosyncope (PPS) and vasovagal syncope (VVS) in children and adolescents are diseases of transient loss of consciousness. It is difficult to distinguish them clinically. This paper will study the differential diagnostic value of P wave dispersion (Pd) and QT interval dispersion (QTd) between PPS and VVS.

Methods: The 31 children with PPS and 40 children with VVS from July 2014 to November 2023 were enrolled as the study group. Meanwhile, 30 healthy children who underwent a physical examination at the same hospital were matched to the control group. P wave duration and QT interval in the 12-lead electrocardiogram were measured at the baseline.

Results: (1) Comparison between groups: ① The Pd, corrected P wave dispersion (Pcd), QTd, and corrected QT interval dispersion (QTcd) in PPS group were significantly higher than those in control group (P < 0.05). The minimum P wave duration (Pmin) and corrected P wave duration (Pcmin) in PPS group were significantly lower than those in control group (P < 0.05). There were no significant differences in maximum P wave duration (Pmax), corrected maximum P-wave duration (Pcmax), maximum QT interval (QTmax), minimum QT interval (QTmin), corrected maximum QT interval (QTcmax), and corrected minimum QT interval (QTcmin) between PPS group and control group (P > 0.05). ② The Pd, Pcd, QTd, and QTcd in VVS group were significantly higher than those in control group (P < 0.05). The Pmin, Pcmin, and QTcmin in VVS group were significantly lower than those in control group (P < 0.05). There were no significant differences in Pmax, Pcmax, QTmax, QTmin, and QTcmax between VVS group and control group (P > 0.05). ③ The Pmax, Pd, QTmax, QTd, and QTcd in PPS group were significantly lower than those in VVS group (P < 0.05). There were no significant differences in Pmin, Pcmax, Pcmin, Pcd, QTmin, QTcmax, and QTcmin between PPS group and VVS group (P > 0.05). (2) ROC curve: Pmax, Pd, QTmax, QTd, and QTcd had a certain differential diagnostic value between PPS and VVS in children and adolescents (P < 0.05). QTd had the largest area under curve (0.735), with a sensitivity of 85.00% and a specificity of 53.30% at the cut off value of ≥ 28.11 ms for VVS diagnosis.

Conclusions: In children and adolescents, electrocardiogram parameters such as Pmax, Pd, QTmax, QTd, and QTcd all possess predictive value in differentiating between PPS and VVS. Among them, QTd has the greatest differential diagnostic value.