The ventricular late potentials in children with vasodepressor response of vasovagal syncope.

ABSTRACT

OBJECTIVES: To discuss ventricular late potentials (VLPs) in children with vasodepressor response of vasovagal syncope (VVS-V). METHODS: 184 children diagnosed as VVS-V by head-up tilt test (HUTT) were enrolled as VVS-V group, 105 age and gender matched healthy individuals without syncope were used as control group, then signal-averaged electrocardiogram was measured. RESULTS: HR was decreased [(83.98±12.27) vs (87.28±13.75)bpm, P<0.05] in VVS-V group compared with control group. The prevalence of positive VLPs was not significantly different between the two groups. However the absolute values of TQRS [(84.89±12.05) vs (81.21±8.23)ms, P<0.01], RMS40 [(28.73±7.23) vs (26.89±7.36)µV, P<0.05] and LAS40 [(62.43±19.17) vs (56.79±1.83)ms, P<0.05] were significantly prolonged in VVS-V group compared with control group, and more patients in VVS-V group had abnormal prolonged LAS40 (94.57% vs 83.80%, P<0.01). CONCLUSIONS: The prevalence of positive VLPs was not significantly different, TQRS, RMS40, LAS40 were longer in children with VVS-V in comparison with healthy individuals, and the abnormal LAS40 occurred in a higher proportion of VVS-V group.