The Research Of Blood Pressure Variability In Children With VVS And POTS

Objective: To explore the blood pressure variability(BPV)in children with vasovagal syncope(VVS)and postural tachycardia syndrome(POTS).Methods: The 99 children with VVS(mean age10.98±2.10 years,53female)and 47 children with POTS(mean age11.21±1.83 years,24 female)diagnosed at Pediatric Syncope Clinic or Pediatric Cardiovascular Ward,the Second Xiangya Hospital of Central South University from October2017 to October 2021 were enrolled as the study group.Meanwhile,51 healthy children(mean age10.84±1.87 years,27 female)and 30 healthy children(mean age10.93±1.89 years,15 female)who had physical examination at the Children’s Health Specialist Clinic of the Second Xiangya Hospital of Central South University were matched for control group.All participants were underwent 24-hour ambulatory blood pressure monitoring(24 h ABPM)and collected standard deviation(SD)and coefficient of variation(CV).After intervention,75 VVS and 33 POTS were followed up for 37.50(28.00,62.75)days.VVS were divided into vasoinhibitory type vasovagal syncope group(VVS-VI,46 cases),cardioinhibitory type vasovagal syncope(VVS-CI,1 case,not included in statistics),and mixed type vasovagal syncope group(VVS-M,28 cases)according to different hemodynamic results.According to the intervention effect,they were divided into response group and non-response group.The baseline BPV of the study group and the control group,the baseline BPV of the response group and the non-response group were compared.Results:(1)There were no significant differences in gender,age,height,body weight and body mass index between VVS group,POTS group and control group(P >0.05).(2)The nighttime mean diastolic blood pressure(NDBP)in VVS group at baseline was higher than control group(P < 0.05).The baseline ABPM of VVS group and POTS group were mainly non-dipper blood pressure pattern,and the proportion were higher than that of control group(70.71% vs.45.10%,P=0.002;70.21% vs.56.67%,P=0.224).(3)The baseline nighttime systolic blood pressure standard deviation(NSSD),nighttime diastolic blood pressure standard deviation(NDSD),nighttime systolic blood pressure variation coefficient(NSCV),nighttime diastolic blood pressure variation coefficient(NDCV)in VVS group were higher than those in control group(P < 0.05).The baseline 24-hour diastolic blood pressure standard deviation(24 h DSD),daytime diastolic blood pressure standard deviation(DDSD),NSSD,daytime diastolic blood pressure variation coefficient(DDCV),NSCV in POTS group were higher than those in control group(P<0.05).There was no significant difference in baseline BPV between VVS group and POTS group(P > 0.05).(4)There were no significant differences in gender,height,body weight,body mass index,type of baseline 24 h ABPM,baseline 24 h ABPM mean blood pressure between the VVS-VI response group and the non-response group(P>0.05),the age,NDSD,NDCV in VVS-VI nonresponse group were higher than response group(P<0.05).(5)There were no significant differences in gender,age,height,body weight,body mass index,type of baseline 24 h ABPM,baseline 24 h ABPM mean blood pressure,BPV between the VVS-M response group and the non-response group(P > 0.05).(6)There were no significant differences in gender,body weight,body mass index,type of baseline 24 h ABPM,baseline 24 h ABPM mean blood pressure,BPV between the POTS response group and the non-response group(P> 0.05),the age and height in POTS non-response group were higher than response group(P<0.05).(7)The receiver operating characteristic(ROC)curve analysis: When NDSD was 5.75 mm Hg,the sensitivity and specificity to predict the nonresponse after VVS-VI intervention were 83.30% and 57.10%;When NDCV was 13.21%,the sensitivity and specificity to predict the nonresponse after VVS-VI intervention were 77.80% and 71.40%;the sensitivity and specificity of the two combined indicators(NDSD and NDCV)to predict the non-response after VVS-VI intervention were 77.80%and 67.90%.Conclusions:(1)Both VVS and POTS children had abnormal blood pressure circadian rhythm.Children with VVS mainly increased BPV at night,while children with POTS mainly increased 24 h DSD,daytime diastolic blood pressure BPV and nighttime systolic blood pressure BPV.(2)NDSD,NDCV and two combined indicators(NDSD and NDCV)are effective indexes to predict the intervention effect of VVS-VI.Figures 21;Tables 20;References 58...