Prognostic value of rate-pressure product in children with postural tachycardia syndrome / 中华实用儿科临床杂志

ABSTRACT

Objective:To investigate the value of rate-pressure product (RPP) in predicating the prognosis of postural tachycardia syndrome (POTS) in children.Methods:Fifty-three children (26 males and 27 females) aged 5 to 15 who had syncope of unknown reasons or presyncope and were diagnosed with POTS by head-up tilt test (HUTT) at the Children′s Syncope Specialist Clinic, the Second Xiangya Hospital, Central South University from April 2012 to May 2019 were selected as the POTS group.Thirty-eight children aged 5 to 16 (19 males and 19 females) who underwent medical examinations at the Children′s Health Specialist Clinic of the Second Xiangya Hospital, Central South University over the same period were enrolled as controls (control group). POTS children were followed up after intervention and they were divided into the response group ( n=40) and the non-response group ( n=13) according to the follow-up results.The products (RPP0, RPP5, RPP10) of the heart rate (HR0, HR5, HR10) and systolic blood pressure (SBP0, SBP5, SBP10) at baseline (HUTT 0 min), HUTT 5 min and HUTT 10 min were calculated.Statistical analysis was performed using SPSS 22.0 software and EmpowerStats software. Results:(1) There was no statistical difference in age and gender between the POTS group and the control group (all P> 0.05). (2) HR5 [(115.45±14.50) times/min vs.(95.79±13.89) times/min], HR10 [(120.57±16.13) times/min vs.(96.05±12.43) times/min], RPP5 (12 814.55±2 304.56 vs.10 371.42±1 910.20), and RPP10 (13 449.17±2 360.40 vs.10 523.18±1 771.48) in the POTS group were significantly higher than those in the control group( t=0.799, 7.842, 5.747, 6.446, all P<0.01). No statistical difference of HR0 and RPP0 was observed between the 2 groups (all P>0.05). (3) In the POTS group HR5 [(98.73±12.43) times/min vs.(113.77±17.65) times/min], HR10 [(96.90±13.96) times/min vs.(119.08±13.52) times/min], RPP5 (11 125.45±1 952.35 vs.12 914.69±3 192.12) and RPP10 (10 819.58± 2 144.26 vs.13 375.46±2 807.01) in the response group were significantly lower than those in the non-response group( t=3.406, 5.012, 2.432, 3.455, all P<0.01). HR0 and RPP0 were no significantly different between the 2 groups(all P>0.05). (4) When SBP10<114 mmHg(1 mmHg= 0.133 kPa), the probability of response after POTS intervention increased by 10% with every 1 mmHg increase in SBP10, and there was a non-linear relationship between the 2 group ( P<0.05). (5) The receiver operating characteristic curve suggested that when RPP5 was 11 548.50, the sensitivity and specificity to predict the response after POTS intervention were 81.82% and 61.70%, respectively.When RPP10 was 10 988.00, the sensitivity and specificity were 77.78% and 86.21%, respectively. Conclusions:RPP is closely related to the intervention effect of POTS in children.RPP5 and RPP10 can predict the prognosis of POTS in children.There is a non-linear relationship between SBP10 and the intervention effect of POTS in children.