cpet basics and interpretation

1. CARDIOPULMONARY
EXERCISE TESTING
DR SHLESHA R PRADHAN
DNB CARDIOLOGY RESIDENT

2. • CARDIOPULMONARY EXERCISE TESTING (CPET) PROVIDES AN INTEGRATED
EVALUATION OF THE CARDIORESPIRATORY SYSTEM DURING EXERCISE.
INDICATIONS-
UNDIAGNOSED EXERCISE INTOLERANCE ( DYSPNEA, FATIGUE)
ASSESSMENT OF EXERCISE TOLERANCE IN PATIENTS WITH KNOWN
PULMONARY OR CARDIAC DISEASE( HF, HOCM, PAH, MI, MITOCHONDRIAL
MYOPATHY)
PREOPERATIVE EVALUATION FOR LUNG RESECTION, ABDOMINAL AORTIC
ANNEURYSM REPAIR, RADICAL CYSTECTOMY, LIVER RESECTION, LIVER
TRANSPLANTATION, COLORECTAL SURGERY, BARIATRIC SURGERY
ASSESSMENT OF IMPAIRMENT FOR DISABILITY CLAIM

4. TYPES OF EXERCISE
• MECHANICAL (DYNAMIC, STATIC) AND METABOLIC (AEROBIC, ANAEROBIC)
PROPERTIES.
• DYNAMIC (ISOTONIC)
• ECCENTRIC (LENGTHENING) CONCENTRIC (SHORTENING)
• STATIC (ISOMETRIC)
• CURRENT CLINICAL EXERCISE TESTING PROCEDURES MANIFEST A PREDOMINANT
DYNAMIC–AEROBIC (ENDURANCE) COMPONENT

8. CARDIOVASCULAR RESPONSES TO EXERCISE
IN NORMAL SUBJECTS
• CARDIAC OUTPUT IS INCREASED BY AN AUGMENTATION IN
STROKE VOLUME (MEDIATED THROUGH THE FRANK-
STARLING MECHANISM) AND HEART RATE (HR), AS WELL AS
AN INCREASING PERIPHERAL ARTERIOVENOUS OXYGEN
DIFFERENCE.
• HOWEVER, AT MODERATE- TO HIGH-INTENSITY EXERCISE,
THE CONTINUED RISE IN CARDIAC OUTPUT IS PRIMARILY
ATTRIBUTABLE TO AN INCREASE IN HR, AS STROKE VOLUME
TYPICALLY REACHES A PLATEAU AT 50% TO 60% OF MAXIMAL

10. • HR RESPONSE-
INCREASE IN HR THAT IS ATTRIBUTABLE TO A DECREASE IN VAGAL TONE,
FOLLOWED BY AN INCREASE IN SYMPATHETIC OUTFLOW
MAXIMUM PREDICTED HR=220–AGE IN YEARS (±12 BEATS PER MINUTE)
85% OF AGE-PREDICTED MAXIMAL HR
A NORMAL INCREASE IN HR DURING EXERCISE IS ≈10 BPM PER METABOLIC
EQUIVALENT (MET)
UNABLE TO ADEQUATELY INCREASE HR-SINUS NODE DYSFUNCTION,
PROGNOSTICATING CARDIAC DISEASES AND DEFINED AS CHRONOTROPIC
INCOMPETENCE.
HR RECOVERY- CHANGE IN HR IMMEDIATELY AFTER TERMINATION OF THE EXERCISE
HR HAS RAPID FALL DURING THE FIRST 30 SECONDS AFTER EXERCISE, FOLLOWED BY A SLOWER
RETURN TO THE PREEXERCISE LEVEL. (VAGAL REACTIVATION)

11. • ARTERIAL BLOOD PRESSURE RESPONSE-
SYSTOLIC BLOOD PRESSURE, MEAN ARTERIAL PRESSURE, AND PULSE PRESSURE
USUALLY INCREASES
DIASTOLIC BLOOD PRESSURE CAN REMAIN UNCHANGED OR DECREASE
AVERAGE RISE IN SBP DURING PROGRESSIVE EXERCISE TEST IS ABOUT 10
MMHG/MET
• MYOCARDIAL OXYGEN UPTAKE
DETERMINED PRIMARILY BY INTRAMYOCARDIAL WALL STRESS (I.E THE PRODUCT
OF LV PRESSURE AND VOLUME, DIVIDED BY LV WALL THICKNESS),
CONTRACTILITY, AND HR.ACCURATE MEASUREMENT OF MYOCARDIAL OXYGEN
UPTAKE REQUIRES CATH STUDY
CLINICALLY= PRODUCT OF HR AND SYSTOLIC BLOOD PRESSURE
A LINEAR RELATIONSHIP EXISTS BETWEEN MYOCARDIAL OXYGEN UPTAKE AND
CORONARY BLOOD FLOW.

12. • OXYGEN UPTAKE AND THE VENTILATORY THRESHOLD
VO2 MAX- IS THE PEAK OXYGEN UPTAKE ACHIEVED DURING THE PERFORMANCE OF
DYNAMIC EXERCISE INVOLVING A LARGE PART OF TOTAL MUSCLE MASS.
CONSIDERED AS THE BEST MEASURE OF CARDIOVASCULAR FITNESS AND EXERCISE
CAPACITY
VO2 PEAK= VO2MAX
SUBMAXIMAL OXYGEN UPTAKE -PERCENTAGE OF V̇ O2 MAX (EG, 60%, 70%, OR 80% OF
V̇ O2 MAX) IN DESIGNATING EXERCISE WORKLOAD OR INTENSITY.
OXYGEN UPTAKE CAN BE EXPRESSED IN MULTIPLES OF RESTING OXYGEN
REQUIREMENTS-(METS)
WHEREBY A UNIT OF SITTING/RESTING OXYGEN UPTAKE (1 MET) IS DEFINED AS ≈3.5
ML O2 PER KILOGRAM OF BODY WEIGHT PER MINUTE (ML KG−1 MIN−1)
FOR EXAMPLE, AN OXYGEN UPTAKE EXPRESSED AS A 7-MET LEVEL WOULD EQUAL 24.5
ML KG−1 MIN−1
V̇ O2 MAX IS INFLUENCED BY AGE, SEX, EXERCISE HABITS, HEREDITY, AND

14. MAX AEROBIC CAPACITY-PEAK VO2 /
VO2MAX
• VO2 MAX IS EQUAL TO THE PRODUCT OF MAXIMUM CARDIAC OUTPUT AND
MAXIMUM ARTERIOVENOUS OXYGEN DIFFERENCE
• VO2 IS OXYGEN UPTAKE
• VO2 MAX V/S VO2 PEAK
• SURROGATE MARKER OF CARDIAC OUTPUT
• GLOBAL ASSESSMENT OF RESP CARDIAC BLOOD AND MUSCLE FUNCTION
• >84% OF PREDICTED IS NORMAL
• RESTING VO2 3.5ML/KG/MIN
• VO2 MAX 30-50 ML/KG/MIN

17. VENTILATORY THRESHOLD(VT) /
ANAEROBIC THRESHOLD
• VENTILATORY THRESHOLD IS ANOTHER MEASURE OF RELATIVE WORK
EFFORT AND REPRESENTS THE POINT AT WHICH VENTILATION ABRUPTLY
INCREASES IN RESPONSE TO INCREASING CARBON DIOXIDE PRODUCTION (V̇ CO2
) ASSOCIATED WITH INCREASED WORK RATE, DESPITE INCREASING OXYGEN
UPTAKE.
ESTIMATE OF ONSET OF MET ACIDOSIS DURING EXERCISE
INDICATED UPPER LIMIT OF EXERCISE THAT CAN BE PERFORMED AEROBICALLY
50-60% OF VO2 MAX IN NORMAL SUBJECTS
IT IS AN IMPORTANT SUBMAXIMAL MEASURE OF EXERCISE TOLERANCE THAT IS
NOT AS SUBJECT TO PATIENT EFFORT AS PEAK VO2, EXERCISE TIME, OR
ESTIMATED METS.
HEART FAILURE-ACTION TRIAL

18. METHODS-
• V SLOPE
• VENTILATORY EQUIVALENTS
• END TIDAL PRESSURE METHODS

20. MINUTE VENTILATION/CO2 RELATIONSHIP
(VE/VCO2)
VENTILATORY EFFICIENCY
• VE/VCO2 DENOTES AMOUNT OF VE TO ELIMINATE 1L OF VCO2
• IT IS NON INVASIVE MEASUREMENT OF EFFICIENCY OF VENTILATION
• MEASURED THROUGHOUT BUT REPORTED AT AT(NEAR NADIR) WHEN PAC02 IS
STEADY, TO AVOID THE EFFECT OF HYPERVENTILATION ACIDOSIS
• NORMALLY <34

22. PEAK EXPIRATORY EXCHANGE RATIO (RER)
(VCO2/VO2)
• THE RESPIRATORY EXCHANGE RATIO (RER), DEFINED AS THE RATIO BETWEEN
VCO2 AND VO2, OBTAINED EXCLUSIVELY FROM VENTILATORY EXPIRED GAS
ANALYSIS, OBVIATES THE NEED TO ASSESS HEART RATE IN DETERMINING
SUBJECT EFFORT.
• CAN BE USED IN PTS USING BETA BLOCKERS
• MOST ACCURATE AND RELIABLE GAUGE OF SUBJECT EFFORT
• A PEAK RER OF >=1.10 IS GENERALLY CONSIDERED AN INDICATION OF
EXCELLENT SUBJECT EFFORT DURING CPX, BUT IT IS NOT AN INDICATION TO
STOP THE TEST.
• USEFUL MARKER IN CLINICAL TRIALS
• SIGNIFICANT CHANGE IN EXERCISE CAPACITY DURING FOLLOW-UP TESTING
WITH SIMILAR PEAK RER VALUES PROVIDES STRONG SUPPORT FOR THE
ASSERTION THAT OBSERVED CHANGES ARE SECONDARY TO THE INTERVENTION

23. EXPERCISE OSCILLATORY BREATHING (EOB)

24. ADDITIONAL CPX VARIABLES HAVING
POTENTIAL VALUE
• OXYGEN UPTAKE EFFICIENCY SLOPE (OUES) –
DERIVED FROM THE RELATIONSHIP BETWEEN VO2 (PLOTTED ON THE Y AXIS) AND
THE LOG TRANSFORMATION OF VE (X AXIS).
IT IS A METRIC THAT EXPRESSES THE VENTILATORY REQUIREMENT FOR A GIVEN
VO2.
HF- LOWER QUES.
PROGNOSTIC MARKER IN HF AND IN HEART TX PATIENTS
• EXERCISE VENTILATORY POWER (EPV)-
RATIO BETWEEN PEAK SBP AND THE VE/VCO2 SLOPE
LOWER EVP(<3.5 MM HG) REFLECTED A HIGHLY UNFAVORABLE CONDITION THAT
WAS INDICATIVE OF A SEVERELY IMPAIRED PEAK VO2 AND CO RESPONSE TO
EXERCISE.

25. • CIRCULATORY POWER
CARDIAC POWER – CO * MEAN ARTERIAL BP
PATIENTS WITH HF WHO EXHIBIT BOTH LOW PEAK VO2 AND LOW CARDIAC POWER
HAVE BEEN SHOWN TO HAVE WORSE OUTCOMES THAN THOSE WITH LOW PEAK
VO2 AND PRESERVED CARDIAC POWER
INDEX CIRCULATORY POWER- PEAK VO2 * SBP
VALUABLE NONINVASIVE MARKER OF DISEASE STATUS
• NON INVASIVE DETERMINATION OF CO-
ALTHOUGH THE FICK AND THERMODILUTION METHODS REMAIN THE GOLD
STANDARDS FOR THE MEASUREMENT OF CO,SEVERAL REBREATHING METHODS
THAT USE CPX ARE AVAILABLE.

27. ABSOLUTE CONTRAINDICATIONS
● ACUTE MYOCARDIAL INFARCTION (MI), WITHIN 2 DAYS
● ONGOING UNSTABLE ANGINA
● UNCONTROLLED CARDIAC ARRHYTHMIA WITH HEMODYNAMIC COMPROMISE
● ACTIVE ENDOCARDITIS
● SYMPTOMATIC SEVERE AORTIC STENOSIS
● DECOMPENSATED HEART FAILURE
● ACUTE PULMONARY EMBOLISM, PULMONARY INFARCTION, OR DEEP VEIN
THROMBOSIS
● ACUTE MYOCARDITIS OR PERICARDITIS
● ACUTE AORTIC DISSECTION
● PHYSICAL DISABILITY THAT PRECLUDES SAFE AND ADEQUATE TESTING

28. RELATIVE CONTRAINDICATIONS
● KNOWN OBSTRUCTIVE LEFT MAIN CORONARY ARTERY STENOSIS
● MODERATE TO SEVERE AORTIC STENOSIS WITH UNCERTAIN RELATION TO
SYMPTOMS
● TACHYARRHYTHMIAS WITH UNCONTROLLED VENTRICULAR RATES
● ACQUIRED ADVANCED OR COMPLETE HEART BLOCK
● HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY WITH SEVERE RESTING
GRADIENT
● RECENT STROKE OR TRANSIENT ISCHEMIC ATTACK
● MENTAL IMPAIRMENT WITH LIMITED ABILITY TO COOPERATE
● RESTING HYPERTENSION WITH SYSTOLIC OR DIASTOLIC BLOOD PRESSURES
>200/110 MMHG

31. EXERCISE PROTOCOL
• BLAKE AND WARE
• NAUGHTON
• BRUCE AND MODIFIED BRUCE PROTOCOL

36. FLOW VOLUME CURVE

40. CLINICAL APPLICATION OF CPET
• HEART FAILURE – SYSTOLIC FAILURE
DETERMINATION OF PEAK VO2 DURING A MAXIMAL SYMPTOM-LIMITED TREADMILL
OR BICYCLE CPX IS THE MOST OBJECTIVE METHOD TO ASSESS EXERCISE CAPACITY IN
HEART FAILURE PATIENTS.
APPLICATION IN THE FUNCTIONAL ASSESSMENT OF PATIENTS WITH HEART FAILURE.
BY DETERMINATION OF VENTILATORY THRESHOLD THE PHYSICIAN CAN ASSESS HOW
CLOSE THE PATIENT IS TO ACHIEVING HIS OR HER MAXIMAL EFFORT.
USEFUL IN-
ASSESSING SEVERITY OF THE DISEASE
WHETHER HEART FAILURE IS THE CAUSE OF EXERCISE LIMITATION
PROVIDE IMPORTANT PROGNOSTIC INFORMATION AND IDENTIFY CANDIDATES FOR
CARDIAC TRANSPLANTATION OR OTHER ADVANCED TREATMENTS

41. VO2MAX
• A VO2 OF 14 ML /KG /MIN WAS USED AS A CRITERION FOR ACCEPTANCE FOR
CARDIAC TRANSPLANTATION.
• ONE-YEAR SURVIVAL WAS 94% IN PATIENTS WITH A VO2 14 ML/ KG/ MIN
• AFFECTED BY AGE , SEX , OBESITY, MUSCLE MASS, BODY COMPOSITION,
DECONDITIONING AND DRUG USED
VE/VCO2 SLOPE
• BETTER THAN V02MAX ALONE, DOES NOT REQUIRE MAXIMAL EFFORT
• HEART FAILURE PATIENTS WITH A PEAK VO2 10 ML/KG/MIN OR A VE/VCO2 SLOPE
>40 SHOULD BE CONSIDERED TO BE IN THE HIGHEST-RISK CATEGORY
CARDIAC POWER MEASUREMENTS (PEAK CARDIAC OUTPUT *MEAN ARTERIAL
PRESSURE)
TOTAL HEART FAILURE SURVIVAL SCORE

42. • HEART FAILURE – DYSTOLIC FAILURE
OXYGEN-UPTAKE EFFICIENCY SLOPE, VE/VCO2 SLOPE, EXERCISE OSCILLATORY
BREATHING ARE ARE DECREASED MORE IN DIASTOLIC FAILURE, CARRIES PROGNOSTIC
VALUE
• EVALUATION OF DYSPNEA
EXERCISE-INDUCED BRONCHOCONSTRICTION, POSTEXERCISE MEASUREMENTS OF FEV1
AND THE IDENTIFICATION OF EXERCISE-INDUCED OBSTRUCTION BY ANALYSIS OF
EXERCISE FLOW-VOLUME LOOPS
IMPAIRMENT IN OXYGEN DELIVERY DUE TO CIRCULATORY DISORDERS
IMPAIRMENT IN OXYGEN EXTRACTION DUE TO MUSCLE DISORDER
EXERCISE LIMITATION DUE TO LUNG DISEASE IS REFLECTED IN VARIABLES RELATED TO
VENTILATION AND GAS EXCHANGE EFFICIENCY. A DECREASE IN PULSE OXIMETER
SATURATION BY 5% IS COMMONLY USED AS AN INDICATION OF PULMONARY
LIMITATION TO EXERCISE
GAS EXCHANGE INEFFICIENCY IS ALSO CHARACTERISTIC OF SOME CARDIOVASCULAR

44. • SKELETAL MUSCLE FIBER AND MITOCHONDRIAL MYOPATHY
SLOPE DERIVED FROM CHANGE IN CARDIAC OUTPUT (DELTAQ0 AND CHANGE IN
DELTA VO2 DURING PROGRESSIVE EXERCISE CAN BE CALCULATED
PATIENTS WITH PRIMARY MITOCHONDRIAL MYOPATHIES ARE UNABLE TO
ADEQUATELY UTILIZE OXYGEN FOR OXIDATIVE PHOSPHORYLATION; INSTEAD,
LACTIC ACID ACCUMULATES EARLY IN EXERCISE, WHICH LEADS TO EXAGGERATED
CIRCULATORY AND VENTILATORY RESPONSES
EARLY FATIGUE AND A SIGNIFICANTLY INCREASED DELTAQ/DELTA VO2 SLOPE
WITH EXERCISE (15 L/MIN IN MITOCHONDRIAL MYOPATHY VERSUS 5 L/MIN
PATIENTS IN HEALTHY CONTROL SUBJECTS)
THUS, A CONSTELLATION OF LOW PEAK VO2 IN CONJUNCTION WITH AN
ABNORMALLY ELEVATED VE/VO2 RATIO AND HIGH DELTAQ/ DELTAVO2 SLOPE
SHOULD RAISE CONSIDERATION OF PERIPHERAL MYOPATHY AND CONSIDERATION
OF FURTHER TESTING, SUCH AS MUSCLE BIOPSY

45. OTHER UTILITIES-
• EXERCISE PRESCRIPTION
IN CARDIAC, PULMONARY DISEASE AND STROKE PATIENTS
• DISABILITY ASSESSMENT
EMERGING OPTIONS
• CONGENITAL HEART DISEASE
• PULMONARY RESECTION
• PULMONARY HYPERTENSION
• ISCHEMIC HEART DISEASE
• EVALUATION OF CARDIAC PACEMAKER FUNCTION
• ARRYTHMIAS
• BEFORE BARIATRIC SURGERY

46. SYNERGISTIC ASSESSMENTS: CPX AND
DOPPLER ECHOCARDIOGRAPHY

47. INTERPRETATION

59. SUMMARY OF KEY POINTS
• CPET OFFERS THE CLINICIAN THE ABILITY TO OBTAIN A WEALTH OF
INFORMATION BEYOND STANDARD EXERCISE TESTING THAT, WHEN
APPROPRIATELY APPLIED AND INTERPRETED, CAN ASSIST IN THE MANAGEMENT
OF COMPLEX CARDIOVASCULAR AND PULMONARY DISEASE.
• CPET SYSTEMS MUST BE PROPERLY MAINTAINED AND CALIBRATED TO ENSURE
THAT HIGH-QUALITY DATA ARE PROVIDED.
• CPET TEST PROTOCOL SELECTION IS IMPORTANT TO OPTIMIZE THE DATA THAT
ARE DERIVED FROM THE TEST. PROTOCOLS THAT INVOLVE SMALL TO MODEST
WORK-RATE INCREMENTS PER STAGE (EG, RAMP, NAUGHTON, AND BALKE)
MAINTAIN A GREATER RELATIONSHIP BETWEEN VO2 AND WORK RATE THAN DO
THOSE PROTOCOLS WITH LARGER WORK-RATE INCREMENTS.
• CPET TEST SUPERVISION, MONITORING, AND INTERPRETATION SHOULD BE
PERFORMED BY COMPETENT PERSONNEL

60. • INTEGRATION OF CPET TEST DATA WITH EXERCISE-ECG TEST DATA PROVIDES
OPTIMAL COMPREHENSIVE USE OF CPET.
• ELECTROCARDIOGRAPHIC CRITERIA (HEART RATE DYNAMICS, ARRHYTHMIA, ST
SEGMENT CHANGES, AND CONDUCTION DISEASE), HEMODYNAMICS, AND
SYMPTOMS ARE ALL IMPORTANT EXERCISE-RELATED MEASURES THAT
COMPLEMENT AND EXPAND ON THE GAS EXCHANGE INDICES.
• RELATED TECHNOLOGIES USED DURING CPET, SUCH AS THE NONINVASIVE
DETERMINATION OF CARDIAC OUTPUT OR FLOW-VOLUME LOOPS, MAY PROVIDE
USEFUL DIAGNOSTIC AND PROGNOSTIC INFORMATION IN SELECTED PATIENTS

61. THANK YOU