The Screening Of College Students’ Cardiac Function Evaluation Indices In Maximal And Quantitative Stress Test

Object:As cardiac function is the core of physical fitness, on the basis of finding out how the cardiac function evaluation indices change in different stress tests, the aim of this research is to screen out the optimal ones by the mean of factor analysis, which will provide theoretical and practical basis for Cardiac Function Evaluation under different loads. Also, the result will provide reference for making personal exercise prescription and the selection of athletes.Subjects and Methods:84college students aged18-22were recruited voluntarily as the subjects, none of them have athletic training experience or diseases of cardiovascular system or locomotor system. All subjects completed maximal Bruce treadmill test and step tests of2level of height. Heart rate, blood pressure were collected. The cardiorespiratory fitness was monitored by Cortex Metamax3B, cardiac function (including morphological and functional parameter) was examed by echocardiography before and after maximal exercise.Results1. In maximal stress test, in morphological parameter of cardiac function indices, LVIDd, LVIDs, LVPWs, EDV, ESV changed obviously. LVIDd, LVIDs, EDV, ESV declined right after exercise, then rise in the recovery phase and speed were quick, while LVPWs changed oppositely. In functional parameter of cardiac function indices, EF, FS, CO, CI, LVET, E, A, HR, SBP, RPP changed obviously, LVET first declined then increased gradually, others were opposite. However, E, A couldn’t reflect the differences of cardiac function between men and women.2. In quantitative stress test, HR, SBP, RPP rise significantly after the exercise, then dropped in recovery phase. K declined significantly after exercise and rise while recovery. However, RPP couldn’t reflect the gender differences of cardiac function.3. Except K, all the cardiac function indices in Maximal and quantitative stress test have significant differences. After two different step tests, the cardiac function could reach as high as60%of maximal cardio function.Conclusion:1. In maximal stress test, LVIDd, LVIDs, EDV, ESV, EF, FS, CO, CI, LVET, HR, SBP, RPP, FC and oxygen pulse are the indices that are sensitive to load changes.2.In quantitative stress test, HR, SBP, K, FC, oxygen pulse, step exponent, pulse power are sensitive indices to evaluate the cardiac function.3.Step test is an effective intensity that can stimulate cardiac function.4.After screening of cardiac function indices by factor analysis, the effective indices in maximal stress test are EDV, CI, oxygen pulse, RPP, EF, HR; in quantitative stress test the indices are FC、HR、SBP、K.