Change of heart rate recovery after sublingual nitroglycerin head-up tilt table test in children

Objective To investigate the change of heart rate recovery(HRR) after sublingual nitroglycerin head-up tilt table test(SNHUT) in children. Methods Two thousand and eighty-nine cases [aged 2.0-17.9 years old, mean(10.8±2.9) years old] were enrolled in this study, who came from children syncope outpatient department or inpatient department of the Second Xiangya Hospital of Central South University from Jan.2000 to Aug.2012, complaining of unexplained syncope, presyncope, headache, dizziness, chest tightness, sigh etc, which turned out to be head-up tilt table test(HUTT), of which 1 286 children took SNHUT.According to the result of HRR in SNHUT, the children were divided into 2 groups of HRR normal group(n=1 226, male 657 cases, female 569 cases) and HRR abnormal group(n=60, male 35 cases, female 25 cases; <12 years old 47 cases, ≥12 years old 13 cases; SNHUT negative 36 cases and vascular inhibited type vasovagal syncope 24 cases). The 2 groups of children were compared in age, resting heart rate, SNHUT maximum heart rate, the 1 min heart rate after prostration, and body mass index, etc. Results 1.HRR abnormal rate was 4.67%(60/1 286 cases). There was no significant difference between boys and girls(5.06% vs 4.21%, χ2=0.518, P>0.05); there was increasing significance in 0.05).2.The age of HRR abnormal was younger than HRR normal group(t=3.605, P 0.05). Conclusions The children's abnormal rate of HRR with SNHUT was 4.67%, mostly in children under 12 years old.Clinicians should be alert to the occurrence of cardiovascular events and sudden cardiac death in HRR abnormal. Key words: Heart rate recovery; Head-up tilt table test; Child; Gender; Age