直立试验心率变化预测口服补液盐治疗体位性心动过速综合征的效果

Evaluation of the changes in heart rate during head-up test predicting the efficacy of oral rehydration salts on postural tachycardia syndrome in children

目的通过直立试验心率的变化预测口服补液盐（ORS）治疗体位性心动过速综合征（POTS）的效果。方法选择北京大学第一医院儿科2005年7月至2013年9月收治的54例POTS患儿为研究对象，以20名健康儿童作为对照组。对POTS患儿治疗前进行症状严重程度评分及直立试验，给予ORS治疗3个月后再次进行症状严重程度评分及直立试验，根据症状评分减少程度是否大于50％将患儿分为治疗有效组及治疗无效组。应用受试者工作曲线评价卧立位心率差值及直立后10min内最大心率对ORS治疗POTS疗效的预测价值。结果POTS组患儿54例，年龄6～17（11．3±3．0）岁。对照组儿童20名，年龄10-12（11．0±0．8）岁。POTS组患儿卧立位心率差值明显高于对照组，差异有统计学意义[（41±10）比（20±7）次／min，t=-10．441，P=0．000]。POTS患儿治疗后临床症状评分较治疗前显著减低[（3．2±1．8）比（5．7±2．0）分，t=10．958，P〈0．001]，其中有30例POTS患儿复查直立试验，治疗后卧立位心率差值较治疗前有显著降低[（33±11）比（41±11）次／min，t=2．956，P=0．006]。54例POTS患儿治疗有效26例，治疗无效28例。治疗有效组治疗前卧立位心率差值明显高于治疗无效组[（46±10）比（37±9）次／min，t=-3．582，P=0．001]，治疗前直立后10min内最大心率明显高于治疗无效组[（122±12）比（113±10）次／min，t=-2．693，P=0．010]。当卧立位心率差值为41次／rain时，预测应用ORS治疗POTS有效的敏感度和特异度分别为72％和70％；当直立后10min内最大心率达到1230次／min时，预测应用口服补液盐治疗POTS有效的敏感度和特异度分别为48％和78％；卧立位心率差值联合直立后10rain内最大心率预测ORS治疗POTS有效的敏感度为84％，特异度为56％。结论采用POTS患儿直立试验中心率变化预测口服补液盐疗效，具有较好的临床价值。

Objective To predict the therapeutic efficacy of oral rehydration salts （ORS） by quantifying changes in heart rate during the head-up test （HUT） in children with postural tachycardia syndrome （POTS）. Method Fifty-four children from Peking University First Hospital during July 2005 to September 2013 were enrolled into POTS group. Twenty healthy children were enrolled in this study as the control group. Children with POTS were treated with ORS and successfully followed up. HUT test was done before and at the end of the treatment. POTS children were further divided into responding group and the non-responding group depending on if the symptom scores were reduced by 50% or greater after the treatment. The heart rate, systolic blood pressure （SBP） and diastolic blood pressure （DBP） changes during the HUT test were analyzed between the control group and the POTS patients. A receiver operating characteristic （ROC） curve was used to analyze the predictive value of the increase in heart rates （from the supine to upright） and the maximum upright heart rate in 10 minutes after ORS treatment. Result POTSchildren were 6 - 17 （ 11.3 ± 3.0 ） years old and the control group children were 10 - 12 （ 11.0 ± 0. 8 ） years old. The changes of the heart rate during the HUT was different between the POTS patients and the controls （ （41 ±10 ） vs. （ 20 ± 7 ） beats/min, t = - 10. 441, P = 0. 000 ）. There was no significant difference between the two groups in the maximum upright heart rate in 10 minutes during the HUT （ （ 117 ± 12 ） vs. （ 114 ± 8） beats/min, t = - 1. 322, P = 0. 192）. The symptom scores were reduced compared with those before treatment （ （3.2 ±1.8）vs. （5.7 ± 2. 0）, t = 10. 958, P 〈 0. 001 ） and the heart rate changes from supine to upright were decreased in 30 patients （ （33 ±11 ） vs. （41 ± 11 ） beats/rain, t = 2. 956, P = 0. 006）. Compared with the non-responding group （28 cases） , the heart rate change during the HUT test was great in the responding group （26 cases） before treatment （（46 ±10）vs. （37± 9 ）beats/min, t = -3. 582, P =0. 001 ）, and the maximum upright heart rate in 10 minutes was also high in the responding group （ （ 122 ± 12）vs. （ 113 ± 10） beats/rain, t = -2. 693, P =0. 010）. The ROC curve showed that ORS for children with POTS would be predicted to be effective when the pre-treatment increase of heart rate was 41 beats/min （sensitivity 72% and specificity 70% ）, or when the maximum upright heart rate in 10 minutes was 123 beats/min before treatment （ sensitivity 48% specificity 56% ）. When the two indices were used together, sensitivity was 84% and specificity was 56%. Conclusion The changes in heart rate during the HUT was useful in predicting the response to ORS in children with POTS.