1、Mitchell HOROWitz,Cardiopulmonary Exercise Testing,1,專業(yè)知識(shí),Outline,Description of CPET Who should and who should not get CPET When to terminate CPET Exercise physiology Define terms: respiratory exchange ratio, ventilatory equivalent, heart rate reserve, breathing reserve, oxygen pulse Pattern of CPE

2、T results COPD vs CHF,Rationale for Exercise Testing,Cardiopulmonary measurements obtained at rest may not estimate functional capacity reliably,Clinical Exercise Tests,6-min walk test Submaximal Shuttle walk test Incremental, maximal, symptom-limited Exercise bronchoprovocation Exertional oximetry

3、Cardiac stress test CPET,Karlman Wasserman,Coupling of External Ventilation and Cellular Metabolism,Adaptations of Wassermans Gears,General Mechanisms of Exercise Limitation,Pulmonary Ventilatory Respiratory muscle dysfunction Impaired gas exchange Cardiovascular Reduced stroke volume Abnormal HR re

4、sponse Circulatory abnormality Blood abnormality,Peripheral Inactivity Atrophy Neuromuscular dysfunction Reduced oxidative capacity of skeletal muscle Malnutrition Perceptual Motivational Environmental,8,專業(yè)知識(shí),What is CPET?,Symptom-limited exercise test Measure airflow, SpO2, and expired oxygen and c

5、arbon dioxide Allows calculation of peak oxygen consumption, anaerobic threshold,9,專業(yè)知識(shí),Components of Integrated CPET,Symptom-limited ECG HR Measure expired gas Oxygen consumption CO2 production Minute ventilation SpO2 or PO2 Perceptual responses Breathlessness Leg discomfort,Modified Borg CR-10 Sca

6、le,Indications for CPET,Evaluation of dyspnea Distinguish cardiac vs pulmonary vs peripheral limitation vs other Detection of exercise-induced bronchoconstriction Detection of exertional desaturation Pulmonary rehabilitation Exercise intensity/prescription Response to participation Pre-op evaluation

7、 and risk stratification Prognostication of life expectancy Disability determination Fitness evaluation Diagnosis Assess response to therapy,Mortality in CF Patients,Nixon et al; NEJM 327: 1785; 1992. Followed 109 patients with CF for 8 yrs from CPET Peak VO2 81% predicted: 83% survival Peak VO2 59-

8、81% predicted: 51% survival Peak VO2 59% predicted: 28% survival,Mortality in CHF Patients,Mancini et al; Circulation 83: 778; 1991. Peak VO2 14 ml/kg/min: 1-yr survival 94% 2-yr survival 84% Peak VO2 14 ml/kg/min: 1-yr survival 47% 2-yr survival 32%,CPET to Predict Risk of Lung Resection in Lung Ca

9、ncer,Lim et al; Thorax 65:iii1, 2010 Alberts et al; Chest 132:1s, 2007 Balady et al; Circulation 122:191, 2010 Peak VO2 15 ml/kg/min No significant increased risk of complications or death Peak VO2 15 ml/kg/min Increased risk of complications and death Peak VO2 10 ml/kg/min 40-50% mortality Consider

10、 non-surgical management,Absolute Contraindications to CPET,Acute MI Unstable angina Unstable arrhythmia Acute endocarditis, myocarditis, pericarditis Syncope Severe, symptomatic AS Uncontrolled CHF Acute PE, DVT Respiratory failure Uncontrolled asthma SpO2 88% on RA Acute significant non-cardiopulm

11、onary disorder that may affect or be adversely affected by exercise Significant psychiatric/cognitive impairment limiting cooperation,Relative Contraindications to CPET,Left main or 3-V CAD Severe arterial HTN (200/120) Significant pulmonary HTN Tachyarrhythmia, bradyarrhythmia High degree AV block

12、Hypertrophic cardiomyopathy Electrolyte abnormality Moderate stenotic valvular heart disease Advanced or complicated pregnancy Orthopedic impairment,Indications for Early Exercise Termination,Patient request Ischemic ECG changes 2 mm ST depression Chest pain suggestive of ischemia Significant ectopy

13、 2nd or 3rd degree heart block Bpsys 240-250, Bpdias 110-120 Fall in BPsys 20 mmHg SpO2 81-85% Dizziness, faintness Onset confusion Onset pallor,CPET Measurements,Work VO2 VCO2 AT HR ECG BP,R SpO2 ABG Lactate CP Dyspnea Leg fatigue,19,專業(yè)知識(shí),Exercise Modality,Advantages of cycle ergometer Cheaper Safe

14、r Less danger of fall/injury Can stop anytime Direct power calculation Independent of weight Holding bars has no effect Little training needed Easier BP recording, blood draw Requires less space Less noise Advantages of treadmill Attain higher VO2 More functional,Incremental vs Ramp Exercise Test Pr

15、otocol,INCREMENTAL,RAMP,WORK,TIME,TIME,WORK,21,專業(yè)知識(shí),Physiology and Chemistry,Slow vs fast twitch fibers Buffering of lactic acid by bicarbonate CO2 production from carbonic acid Respiratory exchange ratio Ventilatory equivalent of oxygen Ventilatory equivalent of carbon dioxide Graphical determinati

16、on of AT Fick Equation Oxygen pulse,Properties of Skeletal Muscle Fibers,Red = Slow twitch = Type I Sustained activity High mitochondrial density Metabolize glucose aerobically 1 glucose yields 36 ATP Rapid recovery,White = Fast twitch = Type II Rapid burst exercise Few mitochondria Metabolize gluco

17、se anaerobically 1 glucose yields 2 ATP and 2 lactic acid Slow recovery,23,專業(yè)知識(shí),Lactic Acid is Buffered by Bicarbonate,Lactic acid + HCO3 H2CO3 + Lactate H2O + CO2,Respiratory Exchange Ratio,RER= CO2 produced / O2 consumed = VCO2 / VO2,Ventilatory Equivalents,Ventilatory equivalent for carbon dioxid

18、e = Minute ventilation / VCO2 Efficiency of ventilation Liters of ventilation to eliminate 1 L of CO2 Ventilatory equivalent for oxygen = Minute ventilation / VO2 Liters of ventilation per L of oxygen uptake,Relationship of AT to RER and Ventilatory Equiv for O2,Below the anaerobic threshold, with c

19、arbohydrate metabolism, RER=1 (CO2 production = O2 consumption). Above the anaerobic threshold, lactic acid is generated. Lactic acid is buffered by bicarbonate to produce lactate, water, and carbon dioxide. Above the anaerobic threshold, RER 1 (CO2 production O2 consumption). Carbon dioxide regulat

20、es ventilation. Ventilation will disproportionately increase at lactate threshold to eliminate excess CO2. Increase in ventilatory equivalent for oxygen demarcates the anaerobic threshold.,Lactate Threshold,Determination of AT from RER Plot (V Slope Method),Determination of AT from Ventilatory Equiv

21、alent Plot,Wasserman 9-Panel Plot,Oxygen Consumption: Fick Equation,Fick Equation: Q = VO2 / C(a-v)O2 VO2 = Q x C(a-v)O2 VO2 = SV x HR x C(a-v)O2,Heart disease,Heart disease Lung disease Muscle disease Deconditioning,Anemia Lung disease (low SaO2),Arterial oxygen content = (1.34)(SaO2)(Hgb) Venous o

22、xygen content = (1.34)(SvO2)(Hgb),Oxygen Pulse,Oxygen Pulse: “. . .the amount of oxygen consumed by the body from the blood of one systolic discharge of the heart.” Henderson and Prince Am J Physiol 35:106, 1914 Oxygen Pulse = VO2 / HR Fick Equation: VO2 = SV x HR x C(a-v)O2 VO2/HR = SV x C(a-v)O2 O

23、xygen Pulse SV,33,專業(yè)知識(shí),Interpretation of CPET,Peak oxygen consumption Peak HR Peak work Peak ventilation Anaerobic threshold Heart rate reserve Breathing reserve,Heart Rate Reserve,Comparison of actual peak HR and predicted peak HR = (1 Actual/Predicted) x 100% Normal 15%,Estimation of Predicted Pea

24、k HR,220 age For age 40: 220 - 40 = 180 For age 70: 220 - 70 = 150 210 (age x 0.65) For age 40: 210 - (40 x 0.65) = 184 For age 70: 210 - (70 x 0.65) = 164,Breathing Reserve,Comparison of actual peak ventilation and predicted peak ventilation Predicted peak ventilation = MVV, or FEV1 x 35 = (1 Actua

25、l/Predicted) x 100% Normal 30%,Comparison CPET results,Normal CHF COPD Predicted Peak HR150150150 Peak HR150140120 MVV10010050 Peak VO22.01.21.2 AT1.00.61.0 Peak VE604049 Breathing Reserve40%60%2% HR Reserve0%7%20% Borg Breathlessness548 Borg Leg Discomfort885,Cardiac vs Pulmonary Limitation,Heart D

26、isease Breathing reserve 30% Heart rate reserve 15%,CPET Interpretation,Peak VO2 HRR BR AT/VO2max A-a Normal 80% 30% 40% normal Heart disease 30% 30% 15% 40% increased Deconditioning 15% 30% 40% normal,SUMMARY,Cardiopulmonary measurements obtained at rest may not estimate functional capacity reliably. CPET includes the measurement of expired oxygen and carbon dioxide. The Borg scale is a validated instrument for measurement of perceptual responses. CPET may assist in pre-op evaluation a