Cardiopulmonary Exercise Testing

Transcription

1 Cardiopulmonary Exercise Testing Normal Responses and Important Concepts Carl D. Mottram, RRT RPFT FAARC Director - Pulmonary Function Labs and Rehabilitation Associate Professor of Medicine - Mayo Clinic College of Medicine

2 Mission Impossible

3 Karlman Wasserman MD PhD Background

4

5 Cardiopulmonary Exercise Testing Oxygen consumption (VO 2max) Index of cardiopulmonary fitness (gold standard) Cardiovascular response Ventilatory limitation and breathing strategies Gas Exchange Metabolic calculations and derivatives Mottram CD. Manual of Pulmonary Function Testing 10 th Ed 2012

6 Cardiopulmonary Exercise Testing

7 Exercise Testing Guidelines AHA Recommendations for Clinical Exercise Testing Circulation. 2009;119: Circulation 2010, Circulation. 2013;128: ACC/AHA Guidelines for Exercise Testing J Am Coll Cardiol 1997;30: Updated in 2002 ( ATS/ACCP Statement on Cardiopulmonary Exercise Testing Am J Respir Crit Care Med Vol 167. pp , 2003

8 Exercise Testing Guidelines Clinical Stress Testing in the Pediatric Age Group - AHA Council on Cardiovascular Disease in the Young, Committee on Atherosclerosis, Hypertension, and Obesity in Youth. (Circulation. 113(15): , 2006 Apr 18) ACC-AHA Clinical Competency statement on Stress testing (Circulation Oct 2000, Volume 102, Issue 14 ) ATS Pulmonary Function Laboratory Management and Procedure Manual. www. thoracic.org

9 Clinical Indications Evaluate specific symptoms or signs that may be aggravated or induced by exercise Assess or identify abnormal response to exercise in children with disease Assess the effectiveness of medical or surgical treatments Evaluate prognosis, baseline and serial testing Establish baseline for rehabilitation Adapted from AHA 2013 Guideline

10 Exercise Testing Protocols Equipment Ergometer Treadmill Cycle ergometer Other forms of exercise (arm ergometer, step exercise or timed walking) Exhaled gas analysis system ECG monitor and blood pressure Pulse Oximetry or ABG s

11 Exercise Testing Protocols Ergometers

12 Exercise Testing Protocols Treadmill Advantages Natural form of exercise Ease of calibration Higher VO 2 max Disadvantages Risk of accidents and patient fear/anxiety More motion artifact Difficult to obtain blood samples Difficult to quantify work performed

13 Exercise Testing Protocol Cycle Ergometer Safer Advantages Ease of monitoring (e.g. reduced ECG & B/P noise) Quantification of work Ease of obtaining blood samples Disadvantages Difficult to calibrate Leg fatigue and unfamiliarity with cycle exercise Lower VO 2 max

14 Exercise Testing Protocol Steady State Incremental Typically 3 minute stages, but can be longer Large increments in work

15 Protocols - Incremental Step Warm-up 1 minute increments after a warm-up period Variable increases in the workload increments

16 Protocols - Ramp Ramp Continuous increase in work throughout exercise

17 Exercise Testing Protocols Treadmill Bruce Protocol Fast - large increases in workload 3 minute stages 295 subjects (138 male, 157 female), age Reproducibility of V O2max, SEE 3.2% Metabolic equivalent (MET) Exercise time (mins.) Mayo study results Men: (age) Females: (age)

18 Exercise Testing Protocols Treadmill Bruce Treadmill Test in Children 327 children ages 4-15 Predicted values Exercise time, HR, V O2 Cumming GR, et al Amer J of Cardiology (41) pg Naughton & Balke slow - smaller increases constant speed, increasing grade Modified Protocols

19 Exercise Testing Protocols Treadmill Med. Sci. Sports Exerc., Vol. 35, No. 9, pp , Treadmill protocol that uses a linear increase in walking speed coupled with a curvilinear increase in treadmill grade.

20 Exercise Testing Protocols Cycle Ergometer Unit of measure - watt, kpm/m Incremental or ramp protocol Target maximum time of test 8-12 minutes Determining maximal target workload

21 Exercise Testing Protocols Cycle Ergometer To determine predicted maximal power output VO 2 = VO 2 unl + (10 T ) X 10 X S T = time constant S = slope of the rate of increase (V O2 max predicted - V O2 rest)/10 = predicted max. power output (power in watts)

22 Exercise Testing Protocols Cycle Ergometer Example: Predicted V O2 = 2300 mls Rest V O2 = 300 mls /10 = 200 watts predicted max 10 minutes = 200/10 = 20 watt increment or ramp Reduce the predicted max workload for subjects with reduced exercise tolerance Increase the estimated maximal power output for very fit subjects

23 Exercise Testing Protocols Cycle Ergometer Suspected ventilatory limited subjects COPD, Restrictive disease MVV < 40L/min 5 watt incremental or ramp MVV > 40 < watt incremental or ramp

24 CPET Normal Physiologic Response Cardiovascular response Ventilatory response Gas exchange VO 2 response Anaerobic/Ventilatory Threshold

25 Cardiopulmonary Exercise Testing: Cardiac Response ECG/EKG analysis in exercise testing Arrhythmia ST segments Drug effects Other WPW, BBB

26

27 Cardiovascular response Maximum Heart Rate (age) or age >85-90% HR pred. Cardiac Output Stroke volume Weber KT, Janicke JS Cardiopulmonary Exercise Testing, Saunders 1986

28 Cardiovascular response: Cardiac Output Catheter placement Dye dilution & thermodilution Doppler technology Fick Equation Rebreathing methods CO 2 technique Acetylene-Helium or Soluble gas techniques

29 Cardiovascular response Oxygen Pulse Fick principle Cardiac Output = V O2 /A-V difference HR x stroke volume = V O2 /A-V difference O 2 Pulse = V O2 /HR = SV x A-V difference O 2 Pulse = Stroke Volume?

30 Cardiovascular response Blood Pressure Adults Normal : /50-90 Hypertension F Systolic >225 mmhg F Diastolic >90 mmhg F Daida H. Mayo Clinic Proceedings (71) , 1996 Pediatric Maximal exercise systolic pressure is positively related to Ht, workload and resting systolic pressure F James F. Circulation 1980; 61;

31 Ventilatory Capacity Ventilatory Capacity (V Ecap ) Maximal Voluntary Ventilation (MVV) FEV 1 x 40 V Emax = 60-80% of V Ecap Flow limitation FV loops during exercise

32 Ventilatory Capacity Ventilatory Capacity Pediatric 16% 14% 40% 5-10 y.o. n= y.o. n=3319 Restr MildOb SevOb 12% Frequency 10% Frequency 30% 8% 6% 20% 4% 2% 0% 10% MVV/FEV1 0% MVV/FEV1

33 Ventilatory Capacity 231 subjects (111 male, 120 female) Mean V Emax as a fraction of MVV 0.61 (range ) Blackie SP, Fairbarn MS, et al: Normal values and ranges for ventilation and breathing pattern at maximal exercise. Chest 100:136, 1991

34 Ventilatory Capacity MVV = second maneuver that is extrapolated to 1 minute Freedman S. et. al Respiration Physiology (8) , 1970

35 Ventilatory Capacity Ventilatory or Breathing reserve: Ventilatory capacity - V Emax liters (10-15 L minimum) 20-40% Ventilatory limitation Minute Ventilation, l/min V E Capacity. V E Reserve. V E Threshold Oxygen Consumption, l/min Mottram CD. Manual of Pulmonary Function Testing 2012

36 Breathing Kinetics Jones, N. Clinical Exercise Testing, Saunders, 1997

37 Breathing Kinetics Blackie SP, Fairbarn MS, McElvaney NG, et al: Chest 100:136, 1991

38 Breathing Kinetics Jones, N. Clinical Exercise Testing, Saunders, 1997

39 Breathing Kinetics: Flow-Volume Loop Analysis 12 Quantify flow limitation Johnson BD. Weisman IM. Zeballos RJ. Beck KC. Emerging concepts in the evaluation of ventilatory limitation during exercise: the exercise tidal flow- volume loop. Chest. 116(2): , 1999 Aug Flow, l/sec MFVL ext FVL Rest FVL Rest IC Vol of FL -6-8 ext IC Volume, l

40 Breathing Kinetics: Flow-Volume Loop Analysis Quantification of flow limitation Flow/volume characteristics Fixed, variable intra/extra-thoracic obstruction Breathing kinetics Location of tidal breathing on the absolute lung volume scale

41 Flow Volume Loop Dynamic Profiles Flow (L/sec) Ex Rest Rest Rest Normal Ex Exercise Severe COPD Mottram CD, Manual of Pulmonary Function Testing 2012

42 Breathing Kinetics: FVL Analysis Normal

43 Breathing Kinetics: FVL Analysis Flow limitation

44 Breathing Kinetics: FVL Analysis Inappropriate Shift

45 Breathing Kinetics: FVL Analysis Vocal Cord Dysfunction

46 Breathing Kinetics: FVL Analysis Pseudo Asthma type 2

47 CLSI HS-3 Pulse Oximetry (2004) Site and artifact management Multiple sensors Be careful!!! Gas Exchange Pulse Oximetry

48 Gas Exchange - Arterial Blood Gases CLSI H11-A4 Procedures for the Collection of Arterial Blood Specimens Arterial Catheter Radial, brachial Frequency is up to the institutional practice lactate Rest and end-exercise single stick Within 30 seconds

49 Gas Exchange Pa O2 is relatively stable with the (A-a) gradient < 20 Pa O2 may fall in highly trained subjects Example end-exercise ABG: 110/28/7.29

50 Gas Exchange Tidal Volume/Dead Space Ratio (V T /V D ) Normal V T /V D is 30-40% or less Increases with age Increases in smokers Increases with small tidal volumes Increases with pulmonary disease (esp. PE) and shunt Decreases with exercise

51 Gas Exchange V D /V T Rest: 30-40%, Maximal exercise: near 20% Elderly normals: Values higher, but kinetics same

52

53 Metabolic Response Oxygen uptake (VO 2 ) is determined by cellular demand and the subject s maximal rate of O 2 transport VO 2 work-rate relationship ml/min/watt Predicted VO 2 max/peak influenced by height, age, and sex

54 Metabolic Response Fick Equation Reductions in VO 2max can be from a single entity or multifactorial Oded Bar-Or Pediatric Exercise Medicine Human Kinetics 2004

55 Metabolic Response Anaerobic Threshold/Ventilatory Threshold Increasing work causes cellular respiration to utilizes both aerobic and anaerobic pathways to produce energy (Kreb s cycle) Formation of lactate 50-80% of maximal oxygen consumption

56 Metabolic Response Anaerobic Threshold/Ventilatory Threshold Determining Anaerobic threshold or ventilatory threshold ä Change in R ä Ventilatory equivalents ä V-slope Mottram CD. Manual of Pulmonary Function Testing 2012

57 Metabolic Response Anaerobic Threshold/Ventilatory Threshold Ventilatory Equivalents Ratio AT Workload (watts) Isocapnic buffering zone VE/VO2 VE/VCO2 RCP H + + HCO 3 H 2 CO 3 H 2 O + CO 2 Mottram CD. Manual of Pulmonary Function Testing 2012

58 Metabolic Response Anaerobic Threshold/Ventilatory Threshold Lactate kinetics Kanaley JA. Mottram CD. et. al Fatty acid kinetic responses to running above or below lactate threshold. Journal of Applied Physiology. 79(2):439-47, 1995 Aug. End-exercise > 7 mmol/l

59

60

61

62 Patient testing Symptom scales Ratings of Perceived Exertion Borg scale (Original and Modified) 0-4 Visual analog scales Chest pain, chest tightness, asthma symptoms, lightheadedness

63 Patient Testing: Early Termination Angina > 3 (1-4 scale) > 2 mm horizontal or downsloping ST segment depression or elevation Ventricular arrhythmia: VT, sustained PSVT, 3rd degree heart block Systolic or diastolic B/P > 250 and 120 mmhg respectively, or a >20 mm decline of systolic B/P Failure of monitoring system

64 If it were only that simple

65 Cardiopulmonary Exercise Testing Interpretation algorithm Determine maximal study (see slide) and exercise tolerance (VO 2max, VO 2 /kg) Cardiovascular response ECG, B/P, cardiac output, O 2 pulse and symptoms Ventilatory response Ventilatory reserve, breathing kinetics

66 Cardiopulmonary Exercise Testing Interpretation algorithm Gas exchange A-a gradient, V D /V T, PaCO 2 Metabolic Anaerobic threshold, lactate Exercise prescription

67 Cardiopulmonary Exercise Testing - Determining Maximum Effort *** Heart rate response: 85-90% of pred. *** V E max : % of ventilatory capacity ** SaO 2 : 80% * Metabolic Work: RER > or Lactate >7 mmol * Clinical investigator s opinion * = rating of importance

68 Case 1 54 y.o. male c/o dyspnea on exertion Initial shortness of breath (SOB) episode, followed by worsening SOB over the next 2 months Normal labs, ECHO, CXR and CT Past medical history pack year smoking history Occupational history: foreman for a utilities company, no exposures

69 Case 1 Medications: None Physical exam: unremarkable Spirometry: FVC 5.03, FEV , ratio 83% Cardiopulmonary exercise test ordered to quantify any cardiac or respiratory abnormality

70 Exercise REST AT Maximum Workload watts Pred Max %Pred Max Time min:sec 4:40 0:56 0:50 VO2 l/min VO2/kg ml/kg R Cardiac Function Heart Rate bpm Blood Pressure DIRECT mmhg 145/90 235/ /110 Oxygen Pulse ml/beat Ventilation Minute Ventilation 1/min Respiratory Rate per min Tidal Volume ml, BTPS Tidal Volume/FVC t Vent. Equivalent for O2 Ve/VO Blood Gases Arterial ph Arterial PCO2 mmhg Arterial PO2 mmhg Arterial O2 Sat t Arterial Bicarbonate meq/l (A-a) Gradient O2 mmhg P(ET-a) CO2 mmhg VD/VT t Arterial Lactate mm/l Normal study with mild hypertension GC7022

71 Case 1 VE MVV 141 Pred VO2 2.4 l/m Heart Rate Pred. HR 175 Pred. VO2 2.4 l/m VO VO2 GC7022

72 Case 2 56 y.o. male transplant eval. for end-stage renal disease PMH: glomerular nephritis 1989, hemodialysis 3 times per week smoking history Current medications: Nephlex, folic acid and anti-acid

73 Case 2 Physical exam: thin, normal heart sounds, diminished basilar breath sounds Spirometry: FVC 3.83, FEV , ratio 30% severe airflow obstruction CPX ordered to test pulmonary and cardiac reserve prior to surgery

74 Exercise REST Maximum Workload watts 95 Pred Max %Pred Max Time min:sec 2:48 0:45 VO2 l/min VO2/kg ml/kg R Cardiac Function Heart Rate bpm Blood Pressure DIRECT mmhg 140/75 215/85 Oxygen Pulse ml/beat Ventilation Minute Ventilation 1/min Respiratory Rate per min Tidal Volume ml, BTPS Tidal Volume/FVC t Vent. Equivalent for O2 Ve/VO Blood Gases Arterial ph Arterial PCO2 mmhg Arterial PO2 mmhg Arterial O2 Sat t Arterial Bicarbonate meq/l (A-a) Gradient O2 mmhg P(ET-a) CO2 mmhg VD/VT t Arterial Lactate mm/l Ventilatory limitation with mild gas exchange abnormality and reduced exercise capacity RPA5753

75 VE MVV = 43 Pred. VO2 1.8 l/m Heart rate Pred HR 174 Pred VO2 1.8 l/m VO2 VO2 RPA5753

76 Case 3 63 y.o. female c/o dyspnea on exertion Preliminary diagnosis of mild pulmonary hypertension Pulmonary angiogram showed no evidence of embolic disease and Rt. heart catheterization showed 34/16, mean of 22 Medication: Lopressor, Claritin

77 Case 3 Physical exam: Heart S1, S2, lungs clear Spirometry: FVC 3.62, FEV , ratio 77% (Normal) CPX ordered to evaluate dyspnea on exertion

78 Exercise REST AT Maximum Workload watts Pred Max %Pred Max Time min:sec 3:32 0:57 1:08 VO2 l/min VO2/kg ml/kg R Cardiac Function Heart Rate bpm Blood Pressure DIRECT mmhg 150/72 185/75 203/78 Oxygen Pulse ml/beat Ventilation Minute Ventilation 1/min Respiratory Rate per min Tidal Volume ml, BTPS Tidal Volume/FVC t Vent. Equivalent for O2 Ve/VO Blood Gases Arterial ph Arterial PCO2 mmhg Arterial PO2 mmhg Arterial O2 Sat t Arterial Bicarbonate meq/l (A-a) Gradient O2 mmhg P(ET-a) CO2 mmhg VD/VT t Arterial Lactate mm/l Reduced exercise tolerance with severe gas exchange abn. TPK0439

79 VE MVV 93 Pred. VO l/m Heart Rate Pred. HR Pred. VO l/m VO VO2 TPK0439

80 Classic Response to Exercise COPD Pulm Variable Normal Mild Mod Severe Fibrosis vas Cardiac Decond Max heart rate N N N N to N VO 2 max N N to to Cardiac output N N N N N Ventilation N N Aner threshold N N???? to V E max/mvv PaO 2 N N N A-a DO 2 N N VD/VT N N CP

81 Can we stop now? My brain is full!

82 Questions?

83

84 Patient JA 17 y.o. male HPI: healthy until football practices where he experienced lightheadedness and SOB Meds/allergies: none Labs: normal Spirometry: FVC 6.15 (123%), FEV (122%) ratio 84.8%

85 Exercise REST Maximum Workload watts 220 Pred Max %Pred Max Time min:sec 2:12 3:31 O2 saturation (SpO2) % VO2 l/min VO2/kg ml/kg R Cardiac Function Heart Rate bpm Blood Pressure CUFF mmhg 120/65 150/50 200/80 75/63 Oxygen Pulse VO2/HR Ventilation Minute Ventilation 1/min Respiratory Rate per min Tidal Volume ml, BTPS Tidal Volume/FVC t 9 36 Vent. Equivalent for O2 Ve/VO Interpretation: Normal study Patient ID: JA796

86 Patient AS 7 y.o. female single ventricle, post-op bidirectional Glenn Meds: None ROS: General appearance is excellent, mild cyanosis, lung clear Spirometry: FVC 0.91L (55%), FEV1 0.90L (58%), ratio 99% CPET: evaluate exercise tolerance and gas exchange. Possible Fontan candidate

87 Exercise REST Maximum Workload watts 30 Pred Max %Pred Max Time min:sec 2:49 2:04 O2 saturation (SpO2) % VO2 l/min VO2/kg ml/kg R Cardiac Function Heart Rate bpm Blood Pressure CUFF mmhg 98/48 100/62 130/73 Oxygen Pulse VO2/HR Ventilation Minute Ventilation 1/min Respiratory Rate per min Tidal Volume ml, BTPS Tidal Volume/FVC t Interpretation: Vent. Equivalent for Maximal O2 Ve/VO study based on gas exchange criterion. Severe reduction in exercise capacity and gas exchange. Patient ID: AS181

88 Patient AD 20 y.o. male s/p mod-fontan 17 years ago c/o chest pain Meds: Digoxin, Lisinopril, aspirin Labs: normal Spirometry: FVC 4.66L (72%), FEV1 4.17L (78%) ratio 89.5 CPET: evaluate exercise tolerance and chest pain

89 Exercise REST Maximum Workload watts 210 Pred Max %Pred Max Time min:sec 9:00 O2 saturation (SpO2) % VO2 l/min VO2/kg ml/kg R Cardiac Function Heart Rate bpm Blood Pressure CUFF mmhg 123/85 168/83 Oxygen Pulse VO2/HR Ventilation Minute Ventilation 1/min Respiratory Rate per min Tidal Volume ml, BTPS Tidal Volume/FVC t Vent. Equivalent for O2 Ve/VO Interpretation: Moderate reduction in exercise capacity with mild gas exchange abnormality. Patient ID: AD440