Risk Factors and Prognostic Follow-Up of Vasovagal Syncope Children With Seizure-Like Activities During Head-Up Tilt Test Induced-Syncope.

Objectives: To analyze the risk factors associated with seizure-like activities during head up tilt test (HUTT)-induced syncope in children with vasovagal syncope (VVS) and assess the prognosis of these patients.

Methods: This is a retrospective study. VVS children with or without seizure-like activities during HUTT-induced syncope were included in convulsive or non-convulsive group. The clinical characteristics, hemodynamic parameters during HUTT-induced syncope and follow-up data were reviewed from the HUTT case report form and analyzed.

Results: 68 cases (25 males, mean age 11.86 ± 3.35 years) were enrolled in convulsive group and 65 cases in non-convulsive group (24 males, mean age 11.64 ± 2.11 years). There were statistical differences in history duration, response type, and asystole between the two groups (all P < 0.05). Fully adjusted logistic regression showed that the risk of seizure-like activities was increased by 37.18 folds for patients with asystole compared with those without asystole ( P = 0.005), by 308.25 and 6.08 folds for patients with cardioinhibitory type or mixed type compared with vasoinhibitory type ( P < 0.01). No significant difference was exhibited in negative HUTT conversion rate and the proportion of re-syncope patients between the two groups at follow-up (both P > 0.05). None of these convulsive patients underwent pacemaker implantation during follow-up.

Conclusions: Asystole and response type were independent risk factors associated with seizure-like activities. Patients with asystole and mixed or cardioinhibitory responses to HUTT should be closely concerned. However, VVS children with seizure-like activities did not have a poor prognosis at follow-up.