A Preliminary Study Of Z Value Regression Equations Of Aortaand Coronaryartery Of Healthy Juveniles In Chongqing

Objective:To study preliminarily the characteristics of normal measurement values of the aorta and coronary artery of the healthy juveniles in Chongqing,and the relevant Z value(Z scores)regression equations were obtained.Methods:From January 2019 to October 2019,healthy young volunteers from Chongqing were recruited to measure height,weight,head circumference,and chest circumference growth indexes and then the body surface area(BSA)was calculated,and collected other general data such as children’s heart rate,birth weight,father’s height and weight,mother’s height and weight.Echocardiography(Echo)was used to measure the diameter of aortic valve annulus(AVA),aortic sinuses of valsalva(ASV),sinotubular junction(STJ),ascending aorta(AAO),left main coronary artery(LMCA),left anterior descending(LAD),left circumflex(LCX),right coronary artery(RCA).ANOVA was used to compare the difference of measurement values of juveniles in different ages.T-test of independent samples were used to compare the differences of measurement values among different genders.The correlation analysis of children’s age,height,weight,BSA,head circumference,chest circumference,heart rate,birth weight,father’s height and weight,mother’s height and weight with AVA,ASV,STJ,AAO,LMCA,LAD,LCX,RCA measurements were carried out,and the independent variable of regression equations was determined.The linear,square root,cubic polynomial,exponential and power regression analysis of independent variable and AVA,ASV,STJ,AAO,LMCA,LAD,LCX,RCA measurement values were established.The best regression equation was determined according to the coefficient of determination R~2,and the calculation formulas of Z value were calculated.Results:210 juveniles were recruited from Chongqing.There was statistically significant differences of LMCA,LAD,RCA between men and women in the school age group,which men measurement values were more than women(P<0.05).There was no significant difference between men and women with measurement values in other age groups(P>0.05).The age,height,weight,BSA,head circumference and chest circumference of juveniles were positively correlated with the measurement values of AVA,ASV,STJ,AAO,LMCA,LAD,LCX,RCA.BSA was the most correlated and could be used as the independent variable of regression equations.Heart rate was negatively correlated with the measurement values of Echo,while birth weight,father’height and weight,mother’s height and weight were not correlated with the measurement values of Echo(P>0.05).In the regression analysis of the independent variable BSA and AVA,ASV,STJ,AAO,LMCA,LAD,LCX,RCA,the coefficient of determination R~2 of cubic polynomial regression model is the largest,which can be used as the best regression equation to calculate Z value.Conclusion:The Z value regression equations and Z value calculation formulas of the aorta and coronary artery of healthy juveniles in Chongqing were obtained,which reflected the variation of aorta and coronary artery internal diameters with BSA and provided a reference standard for evaluating the cardiac development levels in juveniles.