高血压患者动态血压与心肌做功指数的关系

Relationship between ambulatory blood pressure and myocardial performance index in hypertensive patients

目的 探讨高血压患者动态血压与心肌做功指数（MPI）的关系.方法 连续纳入2013年1—6月于北京大学第三医院心内科就诊的、未经治疗的高血压患者76例,行诊室血压、24h动态血压测量及超声心动图检查.计算得到所有患者的MPI,公式为：MPI=（等容收缩时间＋等容舒张时间）/射血时间.根据左心室MPI将患者分为MPI ＞0.47组（n=38）和≤0.47组（n=38）,比较两组的平均诊室血压、平均动态血压、血压负荷、血压晨峰（清晨血压与夜间最低血压之间的差值）和血压昼夜节律.用多因素线性回归分析来确定MPI的独立相关因素.结果 MPI＞0.47组和≤0.47组相比,MPI高组的24h和日间平均收缩压、24 h、日间和夜间平均舒张压、24h、日间和夜间收缩压负荷、24h、日间和夜间舒张压负荷及收缩压晨峰均显著高于MPI低组（均P＜0.05）,而平均诊室收缩压和舒张压、夜间平均收缩压、舒张压晨峰、夜间收缩压和舒张压较日间下降的百分比两组间差异均无统计学意义（均P＞0.05）.多因素回归分析显示,夜间平均舒张压（β=0.285,P=0.005）、日间收缩压负荷（β=0.397,P＜0.001）与MPI独立相关;其他与MPI独立相关的因素为左心室重量指数（LVMI）和二尖瓣环侧壁舒张早期运动峰速度（Em）.结论 动态血压水平和血压负荷的增加伴随左心室MPI的升高.

Objective To explore the relationship between ambulatory blood pressure and myocardial performance index （MPI） in hypertensive patients.Methods A total of 76 hospitalized patients with untreated hypertension from January to June 2013 were recruited.They received the examinations of office blood pressure,24 h ambulatory blood pressure and echocardiography.MPI was determined by the following formula：MPI =（isovolumic contraction time ＋ isovolumic relaxation time） /ejection time.Based upon left ventricular MPI,they were divided into two groups of MPI 〉0.47 （n =38） and MPI ≤0.47 （n =38）.The mean levels of office blood pressure,ambulatory blood pressure,blood pressure load,morning blood pressure surge （early morning blood pressure minus the lowest night-time blood pressure） and noctumal blood pressure changes were compared between two groups.And the determinants of MPI were identified by multivariate regression analysis.Results As compared to those with MPI ≤0.47,patients with MPI 〉 0.47 had higher 24 h and daytime systolic blood pressures,24 h,daytime and nighttime diastolic blood pressures,24 h,daytime and nighttime systolic blood pressure loads,24 h,daytime and nighttime diastolic blood pressure loads and morning systolic blood pressure surges （all P 〈 0.05）.No inter-group differences existed in the mean levels of office blood pressure,nighttime systolic blood pressure,morning diastolic blood pressure surge,nocturnal systolic or diastolic blood pressure changes （all P 〉 0.05）.Multivariate regression analysis showed that nocturnal diastolic blood pressure （β =0.285,P =0.005） and daytime systolic blood pressure load （β =0.397,P 〈 0.001） were independently associated with MPI.And other factors independently associated with MPI were left ventricular mass index （LVMI） and early diastolic mitral annular velocity （Em）.Conclusion The increases of blood pressure level and blood pressure load are associated with an elevation of left ventricular MPI.