Correlationanalysis Of Spatial QRS-T Angle And Tp-e Interval During Treadmill Exercise Test

Objective: Currently there are many evaluating indicators on cardiac risk factors,such as spatial QRS-T angle, Tp-e interval, QT interval, etc., however indicators ofhigh sensitivity and specificity are still less. The spatial QRS-T angle reflectingventricular depolarization and repolarization level is always used in the clinicalapplication but yet with controversy. For the Tp-e interval, only reflecting ventricularrepolarization level, basically is the conversion of ECG vector loop projection innowadays’ clinical application, namely2-dimension Tp-e interval, its accuracy andclinical applications are quite disputable until now. This paper, by analyzing thedynamic change and correlation between spatial QRS-T angle and spatial Tp-einterval during exercise treadmill test (treadmill exercise test, TET) as well as beforeand after correction, provides a new direction to predict cardiac risk factors.Method: Selecting40adult cases who accepted treadmill exercise test at the FirstAffiliated Hospital of Dalian Medical University from October2013to January2014,all the subjects were excluded from congenital heart disease, organic cardiopathy.Collected normal healthy people QRS-T angle and Tp-e interval data at differenttimes during treadmill exercise test, and make sure nobody take heart rate affectingdrug before test. Patients in each group were no statistically significant differences inage and gender, so were comparable. Continuously synchronized detection on bodysurface12-lead ECG and collected VCG before exercise, finish exercise,1,4,9-minafter exercise. After analysis of the dynamic change and correlation between QRS-Tangle changes and Tp-e intervals on the five VCG of above exercises. Comparison ofgroups through non parametric test, P<0.05was considered statistically significantdifference.Results:(1) The average value and standard deviation of spatial QRS-T angle ofdynamic changes. Before movement (7.23±3.58P <0.05); movement end(9.87±4.64, P <0.05);1minute after movement end(9.56±4.35, P <0.05);4minutes aftermovement end,(8.29±4.26, P <0.05);9minutes after movement end (8.27±4.50, P <0.05). One-way ANOVA and multiple comparisons show that spatial QRS-T anglebefore exercise, exercise end, and1minute after exercise end, the change is mostobvious, with statistical significance.(2)The average value and standard deviation of spatial Tp-e interval dynamic changes..Before movement (1.67±2.75, P <0.05); movement end(1.74±2.63, P <0.05);1minute after movement end (1.76±2.29, P <0.05);4minutes after movementend (1.77±1.63, P <0.05);9minutes after movement end (1.79±1.73, P <0.05).One-way ANOVA shows that Tp-e intervals between each group have no significantdifference.(3) By Pearson correlation, analyze the correlation of QRS-T angle and Tp-einterval for each group before correction. Pearson R value and P value for each group,before movement（R=0.089，P＞0.05）; movement end （R=-0.063，P＞0.05）;1minute after movement end （R=0.096，P＞0.05）;4minutes after movement end（R=-0.255，P＞0.05）;9minutes after movement end（R=-0.041，P＞0.05）. Eachgroup R values were less than0.8, P values were greater than0.05, there was nostatistically significant difference and had no correlation between them. Analyzing thecorrelation of all QRS-T angles and Tp-e intervals (not by group) before and aftercorrection, there was no statistically significant difference as P values were greaterthan0.05, no correlation between them.Conclusion:(1) Spatial QRS-T angle intercepted from treadmill exercise when before,finish,1min after exercise, there are significant differences between each group, withstatistical significance.(2) There was no significant difference on spatial Tp-e intervals intercepted fromtreadmill exercise test when before, finish and1,4,9-min after exercise, so withoutstatistical significance.(3) Spatial QRS-T angle is more sensitive than Tp-e interval with time change,Spatial QRS-Tangle and spatial Tp-e interval is not relevant.