To Verify Whether The Symptom-limited Cardiopulmonary Exercise Test Is The Maximum Extreme Exercise Clinical Study And Its Application In Cardiovascular Disease

Background:Introduction to Cardiopulmonary Exercise Test:Cardiopulmonary exercise test(CPET)is an objective,quantitative and accurate method for the detection of human body function,that considered people as a whole to comprehensively and accurately assess the human heart and lung during exercise load.Comprehensive analysis of continuous dynamic changes such as gas exchange,cardiac electrophysiology,hemodynamics,and load power,that can evaluate the overall reserve function,and judges the cause of exercise limitation.Diagnosis,differential diagnosis of vascular diseases,judgment of disease severity,assessment of prognosis and development of cardiopulmonary disease rehabilitation programs.CPET is also known as the symptom-limited maximum CPET.Standardized operations are especially important.At present,the standards of the various disciplines for the respiratory exchange rate(RER),blood pressure and heart rate in CPET have not been unified as the criteria for stopping the exercise.If a certain peak respiratory exchange rate(Peak RER),a certain blood pressure or a specific heart rate is used as the termination test standard,on the one hand,the functional indicators of some patients may be underestimated,and on the other hand,The patients will be dangerous.Objective:The Max test(Max)is designed during clinical CPET application to verify whether the CPET performed by the clinical subject is the maximum extreme exercise,to verify the accuracy of the quantitative CPET evaluation result,and whether it is feasible and safe to use the specific value of a certain index as the standard for stopping CPET.Methods:216 cases from Fuwai Hospital were selected during June 2017 to January 2019,including 41 healthy person(control group)and 175 with cardiovascular diseases(patient group).After signed the consent form,the CPET and Max were performed.The Max was first attempted in 60 subjects,and then 156 subjects were further expanded.The normal group was a healthy person.The patients had a CPET peak RER<1.10,or the peak heart rate and peak blood pressure were basically non-responsive.When the CPET ended,they had a 5-minute break,then the Max,during which,they cycled with a velocity of>60 r/min,at a constant intensity equivalent to 130%of peak work,until exhausted.The difference and percentage difference between the peak heart rate and the peak oxygen uptake were calculated.(1)If the percentage difference of heart rate and oxygen uptake are all less than-10%.then the Max is defined as failure,otherwise it is successful.(2)If the percentage difference is between-10-10%,then the Max is successful,which proved that the CPET is precise.(3)If the difference is>10%,the Max is successful,which proves that the CPET is non-extreme exercise.Results:Patient group's Peak V O2(L/minf ml·min-1·kg-1),anaerobic threshold(L/min,ml·min-1·kg-1,%pred),Peak O2P(ml/time,%pred),Peak RER,Peak SBP,Peak WR,peak heart rate.OUEP(ratio,%pred)were lower than those of the control group(P<0.05).The V E/V CO2 slope(ratio,%pred)and lowest V E/V CO2(ratio,%pred)were higher in the patient group than in the control group(P<0.05).No adverse events occurred during the CPET and Max in all cases.Among the 216 cases.Max was successful in 198 cases(91.7%).CPET was proved to be maximum extreme exercise for 182 cases,non-maximum extreme exercise for 16 cases,and failed in 18 cases(8.3%).The duration of constant power exercise(48±13 s)in the successful Max was higher than that in the failure case(27± 12 s),and the difference was statistically significant(P<0.05).In the Max cases,the maximum oxygen uptake(1101.6±528.3 ml/min)was larger than that of the CPET non-extreme exercise(860.3±386.1 ml/min),and the difference was statistically significant(P<0.05).The maximal heart rate(132±27 beats/min)was higher in the Max cases than in the CPET non-extreme exercise(113±24 beats/min),and the difference was statistically significant(P<0.05).Conclusion:For CPET with a low peak RER and a maximum challenge,the Max can be completed after recovery 5 minutes to confirm the accuracy of the objective quantitative assessment of CPET.Max is safe and feasible,and that deserved further research and clinical application.