Time Correlation Analysis Of Ventricular Gradient And Heart Rate Recovery During Treadmill Exercise Test

Objective: The research aimed to study the trait of dynamic changes of ventriculargradient（VG) and heart rate recovery(HRR) during treadmill exercise test(TET),whatmore, the correlation between them, which may provide a new predication method ofautonomic nervous function for us in the future.Method: We chose40adults who took part in TET as the order they resorted to thedoctor in the First Affiliated Hospital of Dalian Medical University from October2013to January2014.They were normal subjects in the physical examination (such as a pilot)or patients suspected with coronary heart disease,however,their examination ofcoronary CT were negative. All the subjects were diagnosed with no cardiacarrhythmias、cardiomyopathy、syncope、hypertension、diabetes,and so on, in addition,they had never accepted any drug which would affect the heart rate before excise. Wedetected the ECG continuously when the subjects were exercising. Meanwhile, wecollected vector cardiograms at the period of1,2,3,4,5,6min after exercise. Accordingto the data, we could analyze the changing trait of HRR and VG of six vectorcardiograms after the termination of exercise at the period of1,2,3,4,5,6min, what’smore, the correlation between them. VG and HRR were analyzed with t test respectively,at the same time, the correlation analysis of VG and HRR with linear correlationanalysis, P <0.05was statistically significant.Results:(1) The changes of HRR after exercise concentrated on the first4minutes mainly (the2nd and the1st min32.01±7.612%vs18±6.145%, P <0.05; the3rd and the2nd min is35.98±8.309%vs32.01±7.612%, P <0.05; the4th and the3rd37.79±8.943%vs35.98±8.309%, P <0.05). (2)In different periods after exercise, the changes of VG parameters: the amplitude ofVG focused on the first2minutes (the2nd and the1st min vs1.54±mV vs1.620.362±0.370mV, P <0.05); the horizontal angle of VG focused on the first3minutes(the2ndand the1st min55.96±9.392°vs51.82±10.740°, P <0.05; the3rd and the2nd min58.90±9.740°vs to55.96±9.392°, P <0.05); the vertical angle of VG focused on thefirst2minutes (the2nd and the1st min92.83±13.757°vs to90.37±13.414°, P <0.05).(3)In different periods after exercise,HRR had significant correlation with verticalangle and horizontal angle of VG (R=0.209, P <0.05; R=0.238, P <0.05);however,HRR wasn’t relevant with amplitude of VG(R=0.121, P>0.05).Conclusion: Through the TET,VG had significant correlation with time, thecorrelation focused on the first2min mainly, HRR focused on the first4min.VG hadshorter time detecting window, which meaned VG was more sensitive than HRR. Inconclusion, VG had more opportunity to be a new predication method of evaluating thefunction of autonomic nerve.