The Change Of Heart Rate Recovery After Sublingual Nitroglycerin Head-up Tilt Table Testing With Children

Objective To investigate the change of heart rate recovery (HRR) of children after sublingual nitroglycerin-provocated head-up tilt table test (SNHUT).Methods From2000January to2012August in the Second Xiangya Hospital of Central South University, children (Their ages were2to17.92years old. The average age was10.79±2.94years old) of unexplained syncope in children syncope Outpatient Department or Inpatient Department represent headache, dizziness, chest tightness, sigh. We first tried to rule out that their symptoms were caused by organic heart diseases, cardiovascular diseases, cerebrovascular diseases and other diseases. For this purpose, a series of examinations were conducted to them, including detailed disease history inquiry, physical examination, conventional12-lead electrocardiogram, holter electrocardiogram, echocardiogram,electroencephalogram, cranial CT or MRI and blood biochemistry tests.After obtain written informed consent from participants or guardian, there were2089cases took head-up tilt table test (HUTT),including1666cases of sublingual nitroglycerin-provocated head-up tilt table test (SNHUT), male881cases, female785cases, age2.00～17.92(10.54±2.99) years old,<12years old group997cases,≥12years old group997cases, negative result in HUTT994cases, postural tachycardia syndrome (POTS)8cases, vessel inhibitory types of vasovagal syncope664cases. And there were75cases with abnormal HRR, male42cases, female33cases,<12years old group56cases,≥12years old group19cases, negative result in SNHUT39cases, vessel inhibitory types of vasovagal syncope36cases, not have POTS children. We compared children’s abnormal HRR group to normal HRR group in age, resting heart rate, SNHUT maximum heart rate, after supine heart rate, body mass index etc, and analyzed the related factors of HRR anomalies.Results (1) SNHUT children’s abnormal rate of HRR was4.50%(75/1666), there was no significant difference between men and women (4.77%vs4.20%,χ2=0.307, P>0.05),12years old group was significantly higher than in≥12years old group(5.62%vs2.84%χ2=7.180, P<0.01), HUTT negative and SNHUT positive there was no statistically significant difference (3.92%vs5.42%,/=2.069, P>0.05).(2)There was no significant difference in HRR abnormal group and the normal group about the age, resting heart rate, heart rate reserve ratio and body mass index (P>0.05), SNHUT peak heart rate in HRR normal group was higher than that of abnormal HRR group (t=-9.236,P<0.05), when subjects in prostration after1min, HRR abnormal group was higher than that in HRR normal group (t=11.527, P<0.01).Conclusion The SNHUT children’s abnormal rate of HRR is 4.50%,mostly in children under12years old.There is no statisticant difference in different gander and different result of SNHUT. There is no significant difference in HRR abnormal group and the normal group about the age, resting heart rate, heart rate reserve ratio and body mass index; SNHUT peak heart rate in HRR normal group is higher than that of abnormal HRR group; when subjects in prostration after1min, HRR abnormal group is higher than that in HRR normal group.