[Analysis of clinical features and related factor of syncope and head-up tilt test results in children].

To analyze the relationship between clinical features of vasovagal syncope (VVS) and results of head-up tilt test (HUTT).The study enrolled 146 children who were suspected with VVS from January 2014 to January 2015 in West China Second University Hospital, while other organic diseases were excluded, including 54 males and 92 females, aged from 5-17 years, whose average age was from (11.5±3.2) years old. Specified staff was assigned to inquire clinical histories, perform physical exam and HUTT composed of baseline HUTT (BHUTT) and sublingual nitroglycerin HUTT (SNHUTT). According to HUTT results, the patients were divided into two groups: HUTT positive group confirmed with VVS and HUTT negative group. The distributions of hemodynamic types and most common clinical manifestations were analyzed. The factors which were statistically significant in single factor analysis were selected to perform the Logistic regression for screening independent risk factors for HUTT positivity.Of the 146 patients suspected with VVS, 86 cases were positive for HUTT, while 60 cases were negative. (1)HUTT hemodynamic types: In the total of 86 positive cases, 22 cases were positive at baseline for BHUTT (11 mixed response, 8 vasodepressor and 3 cardiodepressor), while 64 were positive in SNHUTT (34 mixed response, 21 vasodepressor and 9 cardiodepressor). (2)CLINICAL FEATURES: The most common manifestations in HUTT-positive group were, in order, headache or dizziness (66.3%), syncope (65.1%), chest tightness or fatigue (41.9%), nausea, vomiting or abdominal pain (25.6%), palpitation (10.5%). (3)The single factor analysis demonstrated that female (χ(2)=7.402, P=0.007), age>12 years (χ(2)=14.649, P 12 years (OR=3.765, P=0.020), with family history (OR=1.998, P=0.023) or flare-up of syncope(OR=2.298, P=0.022) were independent risk factors for positive HUTT.Female, age>12 years, with family history or flare-up of syncope are related factors for positive HUTT.