Exercise Test PPT

Stress Exercise Testing and

InterpretationDr. Ravinder Narwal

Type of CPX1.Max. Execise test2.Submaximal exercise testing

1. In this strategy, the patients exercise enough to achieve 70% of maximum predicted heart rate for their age (ie, 70% of 220 minus age in years).

2. This test is commonly performed prior to discharge and is followed by maximal exercise testing 6-8 weeks later (when patients aim to achieve 90% of maximum predicted heart rate)

3.Symptom-limited exercise testing1. The patients exercise soon after a cardiac event.2. A representative schedule might begin exercise at

intervals, such as 7-21 days following uncomplicated acute myocardial infarction (MI), 3-10 days following angioplasty, or 14-28 days after bypass surgery.

Indications for CPX

• General indications– Assessment of general fitness– Evaluation of dyspnea

• Evaluation of certain pulmonary disorders– COPD, including EIA– Interstitial lung disease

Indications for CPX

• Evaluation of certain cardiovascular disorders– Pulmonary vascular disorders– Coronary artery disease– Other vascular disorders

• Other general disorders– Neuromuscular disorders– Obesity– Anxiety induced hyperventilation

Exercise Testing

• Best used for :• Patients w/ signs & symptoms who are probably + for CAD

• Persons w/ multiple risk factors but who are asymptomatic

Contraindications for CPX

• General contraindications– Limiting neurological disorders– Limiting neuromuscular disorders– Limiting orthopedic disorders


• Cardiovascular contraindications– Acute pericarditis– CHF– Recent MI (<4 weeks)– 2nd or 3rd degree H block– Significant atrial or ventricular tachyarrhymias


• Uncontrolled hypertension

• Unstable angina

• Recent systemic or pulmonary embolism

• Severe aortic stenosis

• Thrombophlebitis or intracardiac thrombi

Complication of CPXCardiacBradyarrhythmiasSinusAtrioventricular junctionalVentricularAtrioventricular blockAsystoleSudden death (ventricular tachycardia/fibrillation)Myocardial infarctionHeart failureHypotension and shockNoncardiacMusculoskeletal traumaIll-defined and miscellaneousSevere fatigue sometimes persisting for days, dizziness, fainting, body aches, delayed feelings of illness

Key Points of Exercise Testing

• Manual SBP measurement (not automated) most important for safety

• Adjust to clinical history• No Age predicted Heart Rate Targets• The BORG Scale of Perceived Exertion• METs• Fit protocol to patient (RAMP)• Use standard ECG analysis/ 3 minute recovery/

use scores• Heart rate recovery • Expired Gas Analysis?

6-20 BORG BORG

SCALESCALE

6

7 Very, very light

8

9 Very light

10

11Fairly light

12

13Somewhat hard

14

15Hard

16

17Very hard

18

19Very, very hard

20

RPE

SC

ALE

0 No exertion at all 0.5 Extremely light (just noticeable) 1 Very light 2 Light 3 Somewhat hard 4 5 Hard (heavy) 6 7 Very hard 8 9 10 Extremely hard (almost maximal) * Maximal exertion

Perceived Exertion Scale (CR 10) Adapted from Borg (1998)

Symptom-Sign Limited Testing Endpoints – When to

stop! Dyspnea, fatigue, chest pain

Systolic blood pressure drop

ECG--ST changes, arrhythmias

Physician Assessment

Borg Scale (17 or greater)

Target Heart Rate

• Approximates the actual heart rate at an oxygen consumption of 65 to 75% of the predicted vo2max

How to read an Exercise ECG

Good skin prepNot one beatThree consistent complexes

Averages can helpThree minute recovery

Types of Exercise Isometric (Static)

–weight-lifting–pressure work for heart, limited cardiac output, proportional to effort

Isotonic (Dynamic)–walking, running, swimming, cycling–Flow work for heart, proportional to external work

Mixed

Problems with Age-Predicted Maximal Heart Rate

Which Regression Formula? (220 - ..5 x Age) Confounded by Beta Blockers A percent value target will be maximal for some and sub-max for others

Borg scale is better for evaluating Effort Do Not Use Target Heart Rate to Terminate the Test or as the Only Indicator of Effort or adequacy of test

Information Obtained From CPX

Monitor The Patient on CPX

• HR & BP• Anginal Scale• Dyspnea Scale• Borg’s RPE Scale• EKG monitoring - Leads I, II, V5• Patient’s subjective symptomatology


– Lung function• RR• Vt and VE• Spo2• Oxygen uptake or consumption (VO2 and

vo2max• Carbon dioxide production (VCO2)• Respiratory quotient (RQ)


• Cardiovascular function– Hr– B/p– ECG– O2 pulse (O2 consumption per beat)– Cardiac output– HR reserve ( 1-[HRmax –Hrrest/

Hrpred.Max – Hrrest]


• Metabolic equivalents of energy expenditure (METS)

– 1 MET equals +/- 3.5 ml O2 consumption per kg of body weight per minute (at rest, all pts are at 1 MET)

• Anaerobic threshold (AT)• VD/VT• Breathing reserve (1 – [VEmax/MVV]

Oxygen Consumption During Dynamic Exercise TestingThere are Two Types to Consider:

Myocardial (MO2)–Internal, Cardiac

Ventilatory (VO2)–External, Total Body

Myocardial (MO2)

Systolic Blood Pressure x HR

SBP should rise > 40 mmHg

Drops are ominous (Exertional Hypotension)

Diastolic BP should decline

Ventilatory (VO2) Cardiac Output x a-VO2 Difference

VE x (% Inspired Air Oxygen Content - Expired Air Oxygen Content)

External Work Performed

****Direct relationship with Myocardial O2 demand and Work is altered by beta-blockers, training,...

VO2 VO2 THE FICK EQUATIONTHE FICK EQUATION

VO2 = C.O. x C(a-v)O2VO2 = C.O. x C(a-v)O2

Equipment and Personnel

Equipment and Personnel

• Equipment– Metabolic cart (breath by breath analysis)– Spirometer with computer– Pulse oximeter– Ergometer and/or treadmill– ECG recorder and monitor– B/P cuff (automated if possible)– Crash cart

Equipment

Treadmill tests

Upper arm ergometryRepetitive

lifting/weight carrying test

Devices Used for Exercise

• Ergometer (stationary bicycle)– Pro’s

• Pt. Is seated

• Work load is independent of patient weight or size

– Con’s• Slightly longer learning curve

Devices Used for Exercise

• Treadmill– Pro’s

• Minimal learning curve– Con’s

• Workload dependant upon pt size and weight• Workload varies with handgrip• Can be dangerous

WORKWORK

TREADMILLTREADMILL

WORK WORK

TIME TIME TIME TIME

WORK WORK

Why Ramp?

Individualized test Using Prior Test, history or Questionnaire

Linear increase in heart rate Improved prediction of METs Nine-minute duration for most patients Requires special Treadmill controller or manual control by operator

Types Of Testing protocols

Types Of Tests protocols

• Treadmill tests• Bruce or Ellestad - good for young folks

because the between-stage graduations of grade and speed are more aggressive

• USAFSAM or Naughton - good for older folks because of the more gradual between-stage progressions of grade and speed

Bruce Protocol GXTStage Speed Grade Dur.

I 1.7 mph 10 % 3 min

II 2.5 mph 12 % 3 min

III 3.4 mph 14 % 3 min

IV 4.2 mph 16 % 3 min

V 5.0 mph 18 % 3 min

VI 5.5 mph 20 % 3 min

Modified BruceStage Speed Grade Dur.

I 1.7 mph 0 % 3 min

II 1.7 mph 5 % 3 min


IV 2.5 mph 12 % 3 min

V 3.4 mph 14 % 3 min

VI 4.2 mph 16 % 3 min

VII 5.0 mph 18 % 3 min

USAFSAM GXTStage Speed Grade Dur.

I 2.0 mph 0 % 3 min

II 3.3 mph 0 % 3 min


IV 3.3 mph 10% 3 min

V 3.3 mph 15% 3 min

VI 3.3 mph 20% 3 min

Reasons To Stop The Test• Drop in BP with increases in workload• Moderate to severe angina• Ataxia, dizziness, syncope• Dysrhythmias• ST segment elevations and depressions• Hypertensive responses

CPX Testing significance HRR

Should Heart Rate Recovery be added to ET?

Long known as a indicator of fitness: perhaps better for assessing physical activity than METsRecently found to be a predictor of prognosis after clinical treadmill testingStudies to date have used all-cause mortality

Heart Rate Drop in Recovery

Probably not more predictive than Duke Treadmill Score or METs

Should be calculated along with Scores as part of all treadmill tests

RPP =SBP(MAX) × HR(MAX)

RPP =SBP(MAX) × HR(MAX)

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What is a MET?

What is a MET?

Metabolic Equivalent Term

1 MET = "Basal" aerobic oxygen consumption to stay alive = 3.5 ml O2

/Kg/min

Actually differs with thyroid status, post exercise, obesity, disease states

But by convention just divide ml O2/Kg/min by 3.5

Key MET Values (part 1)

1 MET = "Basal" = 3.5 ml O2 /Kg/min

2 METs = 2 mph on level

4 METs = 4 mph on level

< 5METs = Poor prognosis if < 65; limit immediate post MI; cost of basic activities of daily living

Key MET Values (part 2)

10 METs = As good a prognosis with medical therapy as CABS

13 METs = Excellent prognosis, regardless of other exercise responses

16 METs = Aerobic master athlete

20 METs = Aerobic athlete

Calculation of METs on the Treadmill

METs = Speed x [0.1 + (Grade x 1.8)] + 3.5 3.5

Calculated automatically by Device!

Note: Speed in meters/minute conversion = MPH x 26.8 Grade expressed as a fraction

METs-(Report Exercise Capacity in METs)

Optimize Test by Individualizing for Patient

Adjust test to 8-10 minute duration (aerobic capacity--not endurance)

Use prognostic power of METs

Estimated vs Measured METs

All Clinical Applications based on Estimated Estimated Affected by:

Habituation (Serial Testing) Deconditioning and Disease State

Measured Requires a Mouthpiece and Delicate Equipment

Measured More Accurate and Permits measurement of Gas Exchange Anaerobic Threshold and Other Mxments (VE/VCO2)

Diagnosis vs Prognosis

CARDIAC RISKvs

METs

METs

10 to 15% increase in survival per MET

Can be increased by 25% by a training program

Duke Treadmill Score (uneven lines, elderly?)

Single measurement of steady state heart rate

Can use step or bicycle ergometer

Nomogram is for age 25 years

Need to adjust for older and younger (for which standard table available)

“All-comers” prognostic score

SCORE = (1=yes, 0=no)

METs<5 + Age>65 + History of CHF + History of MI or Q wave

a=0, b=1, c=2, d=more than 2

Interpretation

Parameters at Max Parameters at Max exerciseexercise

Poor conditioningPoor conditioning Pulmonary Pulmonary disordersdisorders

Cardiovascular Cardiovascular disordersdisorders

VO2maxVO2max LowLow LowLow LowLowMETSMETS LowLow LowLow LowLowVEmax/MVVVEmax/MVV LowLow HighHigh LowLowO2 saturationO2 saturation NN LowLow NNVD/VTVD/VT NN N or HighN or High NNHRmax/workloadHRmax/workload HighHigh NN HighHighO2 pulseO2 pulse NN NN LowLow

Diagnosis vs Prognosis

SUMMARYMETs

CPX Testing Procedure and INDICATION

CPX Testing

• Steps in testing

• After filling of Consent form

• Patient prepratation– Baseline READING OR RESTING– Resting EKG– Baseline B/P

AHA/ACC Exercise Testing Guidelines: Recommendations for

Exercise Testing

Diagnosis CAD Prognosis with symptoms/CADAfter MIUsing Ventilatory Gas AnalysisSpecial Groups


Exercise Testing

Special Groups: Pre- and Post-Revascularization Women AsymptomaticPre-surgery Valvular Heart DiseaseCardiac Rhythm Disorders


Exercise Testing

Diagnosis

The ACC/AHA Guidelines for the Diagnostic Use of the Standard

Exercise Test

Class I (Definitely appropriate) - Adult males or females (including RBBB or < 1mm resting ST depression) with an intermediate pre-test probability of coronary artery disease based on gender, age and symptoms (specific exceptions are noted under Class II and III below).

Class IIa (Probably appropriate) - Patients with vasospastic angina.

Diagnostic Use, continued:

•Class IIb (Maybe appropriate) – Patients taking Digoxin with less than 1 mm resting ST depression.

Patients with ECG criteria for left ventricular hypertrophy with less than 1 mm ST depression.

Patients with a high pre-test probability of coronary artery disease by age, symptoms and gender.

Patients with a low pre-test probability of CAD by age, symptoms and gender.

Diagnostic Use, continued:

Class III (Not appropriate) - 1. To use the ST segment response in the diagnosis of coronary artery disease in patients who demonstrate the following baseline ECG abnormalities:

pre-excitation (WPW) syndrome;electronically paced ventricular rhythm; more than one millimeter of resting ST depression;LBBB

2. To use the ST segment response in the diagnosis of coronary artery disease in MI patients

Comparison of Tests for Diagnosis of CAD

Grouping # of Studies

Total # Patients

Sens Spec Predictive Accuracy

Standard ET 147 24,047 68% 77% 73% ET Scores 24 11,788 80% Score Strategy 2 >1000 85% 92% 88%

Thallium Scint 59 6,038 85% 85% 85% SPECT 16+14 5,272 88% 72% 80% Adenosine SPECT 10+4 2,137 89% 80% 85% Exercise ECHO 58 5,000 84% 75% 80% Dobutamine ECHO 5 <1000 88% 84% 86% Dobutamine Scint 20 1014 88% 74% 81% Electron Beam Tomography (EBCT)

16 3,683 60% 70% 65%

Variable Circle response

Sum

Maximal Heart Rate Less than 100 bpm = 30

100 to 129 bpm = 24

130 to 159 bpm =18

160 to 189 bpm =12

190 to 220 bpm =6

Exercise ST Depression

1-2mm =15

> 2mm =25

Age >55 yrs =20

40 to 55 yrs = 12

Angina History Definite/Typical = 5

Probable/atypical =3

Non-cardiac pain =1

Hypercholesterolemia?

Yes=5

Diabetes? Yes=5

Exercise test Occurred =3

induced Angina Reason for stopping =5

Total Score:

MalesChoose

only one per

group

<40=low prob

40-60= intermediate probability

>60=high probability

Positive=-5, Negative=5

Total Score

Reason for stopping =15

induced Angina (x3)Estrogen Status

Occurred =9Exercise test

Yes=10Diabetes? (x2)

Yes=10Smoking? (x2)

Non-cardiac pain =2

Probable/atypical =6

Definite/Typical = 10Angina History (x2)

50 to 65 yrs = 15(x5)

>65 yrs =25Age

> 2mm =10Depression (x2)

1-2mm =6Exercise ST

190 to 220 bpm =4

160 to 189 bpm =8

130 to 159 bpm =12

100 to 129 bpm = 16Rate (x4)

Less than 100 bpm = 20

Maximal Heart

SumCircle response

Variable WomenChoose

only one per

group

<37=low prob

37-57= intermediate probability

>57=high probability


Exercise Testing

Prognosis with symptoms/CAD

The ACC/AHA Guidelines for the Prognostic Use of the Standard Exercise Test

Indications for Exercise Testing to Assess Risk and prognosis in patients with symptoms or a prior history of coronary artery disease:

Class I. Should be used:Patients undergoing initial evaluation with suspected or known CAD. Specific exceptions are noted below in Class IIb.

Patients with suspected or known CAD previously evaluated with significant change in clinical status.

Prognostic Use, continued:

Class IIb. Maybe Appropriate for:Patients who demonstrate the following ECG abnormalities:

Pre-excitation (WPW) syndrome;Electronically paced ventricular rhythm;More than one millimeter of resting ST

depression; andLBBB.

Patients with a stable clinical course who undergo periodic monitoring to guide management

Prognostic Use, continued:

Class IIa. Probably Appropriate: None

Class III. Should not be used for prognostication:

Patients with severe co-morbidity likely to limit life and/or consideration for revascularization procedures

CPX Testing significance Prognostic

Problems with max tests in average/less fit subjects

1. May not be accustomed to exercise at severe levels, so may not reach maximum

2. On a bike, need strong quads, so lightly built subjects, possibly most female subjects, will lack strength to reach VO2max

3. Can use treadmill, but significant minority find treadmill disorienting or have balance problems

Submaximal exercise tests

Most follow this pattern:

Subjects does standardised work scheduleHeart rate is measuredWork capacity at age-predicted heart rate max is calculatedOxygen consumption at work rate calculated for HRmax is estimated from average relation between VO2 and work rate for the test could use a short “ramp” test

Drawbacks of submaximal tests:

Assume reliable HR-VO2 relation across subjects (1 point tests) or linearity of HR relation for multi-point tests

Depend on estimating age-related HRmax.(error +/- 10%)

Assume same VO2-work relation in all subjects, i.e. constant efficiency

Are subject to error from fluctuations in HR due to time of day, eating patterns, uncontrolled stressors.

McArdle estimates a typical submax test can only give VO2max estimates to within +/- 16%

Field Tests

• 12 min run– VO2 = 3.126 (meters in 12 min) - 11.3

• 1.5 mile run– VO2 = 3.5 + 483/(time in minutes)

• Rockport Walking Test (1 mile walk)– VO2 = 132.853 - 0.1692 (BW in kg) - 0.3877 (age in y)

+ 6.315 (gender) - 3.2649 (time in min) - 0.1565 (HR)

– 0 for female; 1 for male; HR at end of walk

Non-exercise methods 1.Use Exercise heart rate variability.

Non-exercise methods 1.Use Exercise heart rate variability.

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0

20

40

60

80

100

120

140

160

180

0 50 100 150 200 250 300 350 400 450

Time, sec

Heart rate variability during exerciseBest by beat variability falls during exercise. This is due to reduction in vagal (parasympathetic) drive to the heart. Part of the way heart rate is increased (NB other factors are increased sympathetic drive and circulating adrenaline)

125

130

135

140

145

150

320 330 340 350 360 370

Time, sec

50

55

60

65

70

75

160 170 180 190 200 210 220 230

Time, sec

“Ins

tant

aneo

us”

hear

t rat

e, m

in-1

Resting Moderate-hard exercise

Non-exercise methods 2.

Use just age, gender, level of physical activity, perceived functional ablility (latter two from simple questionnaires). Claimed can estimate fitness to within +/- 3.4 ml/min.kg (SEE, standard error of estimate, so 5% confidence limit about 7 ml/min.kg). This appears better than any of the “real” tests, so some doubt that comparisons are being made in a fair way….

.

Monitoring change in fitness

Submax exercise tests are much more reliable on repeat testing in the same individual. So for following the effect of an “exercise for health” individual programme, they are fine. But in this situation may be better to forget VO2max altogether. Simply follow trend in final heart rate for a standard exercise, e.g. short step test or timed walk test.

SummaryFitness levels vary markedly between individuals and are highly predictive of future health.

Need simple methods to monitor fitness in individuals and in populations

Various sub-max tests are suitable for this purpose. However, because of inherent non-linearities in the underlying physiology, will have low accuracy.

For reliable VO2max estimates in a performance context or clinically, need a maximum test.



• Manual SBP measurement (not automated) most important for safety

• Adjust to clinical history• No Age predicted Heart Rate Targets• The BORG Scale of Perceived Exertion• METs not Minutes• Fit protocol to patient (RAMP)• Use standard ECG analysis/ 3 minute

recovery/ use scores• Heart rate recovery • Expired Gas Analysis?

What is the most important prognostic measurement from the exercise test?

1. BORG scale estimate2. ST depression3. Exercise time4. Exercise capacity

Question 1

What is the most appropriate indicator of a maximal effort?

1. BORG scale 2. ST depression3. Heart rate4. Exercise capacity

Question 2

Thank you

Documents

Exercise Test PPT