PreParticipation CV Screening and Clinical Exercise Testing

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Section II

• Pre-Participation CV Screening and Clinical
  Exercise Testing

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Pre-Participation CV Screening

• Purpose of pre-participation screening
• Components of screening
• CH 2 Guidelines
• PAR-Q
• Signs and symptoms of CHD Table 2-1
• Risk Factors Table 2-2
• Initial Risk Stratification Table 2-3
• ACSM Guidelines for Screening
• Table 2-7

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Pre-Participation CV Screening

• State of the Practice
• KJM research paper
• New AHA/ACSM position paper
• AHA website

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General Purposes of Exercise Testing (ETT or
GXT)(CH5 ACSM Guidelines)

• Evaluate Exercise Capacity
• Evaluate functional capacity
• VO2 max
• Symptom-limited VO2 (SL-VO2)
• Peak VO2
• Evaluate fitness
• Pre-post exercise training program

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EXERCISE TEST FOR DIAGNOSIS OF CAD

• Principle of diagnostic ETT
• Ischemic responses such as ST segment depression
  and angina indicate the presence of CAD.

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Example

• Rest
• Absence of symptoms
• Normal ECG
• During Exercise
• Symptoms
• ST depression

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Exercise tests used to evaluate patients with a
history of chest pain

• Typical CP of probable ischemic origin
• Atypical Cp of probable non-ischemic origin
• Recurrent or worsening angina

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Evaluate other symptoms

• Dyspnea (shortness of breath)
• Syncope (dizziness)
• Unusual fatigue

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ESTIMATE PROGNOSIS AND SEVERITY OF CAD

• Abnormal test results can give an indication of
  severity of disease (bot not the location of
  stenosis)
• More severe CAD --- poorer long-term prognosis

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ETT Findings Indicating Poorer Prognosis

• Limited exercise capacity
• Exercise induced hypotension (EIH)
• Marked ST depression
• Angina with any of the above

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EVALUATE ARRHYTHMIAS

• Detection of arrhythmias
• Assessment of anti-arrhythmia therapy

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EVALUATION OF THERAPEUTIC INTERVENTIONS

• Pre-post CABG or PTCA to evaluate
  revascularization
• Evaluation of medical therapy

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BASIS FOR EXERCISE PRESCRIPTION

• Determine maximal (peak) heart rate
• Determine exercise tolerance
• Determine ischemic threshold

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POST-MI EVALUATIONS

• Pre-discharge activity guidelines
• Evaluate prognosis

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MEASUREMENTS DURING THE EET

• 1. ECG
• Continuous (oscilloscope)
• Intervals (each stage of graded test)

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MEASUREMENTS DURING THE EET

• 2. Heart Rate
• Each stage
• Peak exercise
• Calculate age predicted maximal heart rate
  (APMHR) achieved
• HR achieved during test / predicted maximal heart
  rate (using 220-age) x 100

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MEASUREMENTS DURING THE EET

• 3. Blood Pressure
• Each stage
• Peak exercise
• Recovery
• Evaluate normal/abnormal response to exercise

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MEASUREMENTS DURING THE EET

• 4. Symptoms and exertion
• Angina(1-4 scale)
• RPE
• Shortness of breath (SOB)
• Dizziness
• Other

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MEASUREMENTS DURING THE EET

• 5. Exercise Duration
• Use to estimate VO2 max
• Sequence for measurements during the EET
  Guidelines Table 5-1 pg. 95

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ETT TERMINATION POINTS

• ACSM Guidelines Table 5-4 pg. 97

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INTERPRETATION OF DIAGNOSTIC EXERCISE TEST

• CH 6 ACSM GUIDELINES
• CH 28 RESOURCE MANUAL

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DIAGNOSTIC TESTS

• Positive exercise test
• ST segment depression and/or angina
• Negative exercise test (Normal) for ischemic
  changes

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DIAGNOSTIC TESTS

• Non-Diagnostic, indeterminate, or inconclusive
  test results
• Dependent upon APMHR achieved
• Negative exercise test for angina and ischemic ST
  segment changes at an inadequate peak heart rate
• Results of the test can not be used to rule out
  CAD

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() TEST RESULTSMARKEDLY () and BORDERLINE ()

• Severity of ECG changes
• Presence and severity of angina
• Early onset of ischemic changes
• Normal BP vs. exercise hypotension

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SENSITIVITY AND SPECIFICITY

• Terms used to describe how reliable a test
  distinguishes diseased from non-diseased states.
• Guidelines Table 6-16 pg. 140

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• Sensitivity A measure of the tests ability to
  give a positive () result when the subject does
  have disease.
• Specificity A measure of the tests ability to
  give a (-) result when the subject does not have
  disease.

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Positive and Negative exercise test results
can be compared to angiographic findings

• True Positive (TP) ( ) ETT and ( ) angiogram
• True Negative (TN) ( ) ETT and ( ) angiogram
• False Positive (FP) ( ) ETT and ( ) angiogram
• False Negative (FN) ( ) ETT and ( ) angiogram

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• Sensitivity TP / TP X FN X 100
• Specificity TN / TN X FP X 100

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Some possible reasons for low Specificity high
FP table 6-18

• 1. LOW pre-test likelihood of disease
• Example women young age low risk factor
  profile asymptomatic
• 2. Abnormal resting ECG
• Example ST changes at rest

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• 3. Medications which affect the ECG
• Example digitalis
• 4. Normal variant
• Example ECG has ST segments that look like
  ischemic ST depression

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Some possible reasons for low Sensitivity high
FN table 6-17

• 1. Inadequate leads monitored
• 2. Canceling vectors
• 3. Single vessel disease
• Collaterals during exercise

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PREDICTIVE VALUE OF ETT RESULTS

• 1. Prevalence of disease in the population tested
  (Bayes Theorem) influences predictive value of
  ETT results
• The pre-test likelihood of disease influences the
  post-test probability of having the disease

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• Example
• () ETT 50 y/o male HTN hypercholesterolemia
  Hx CP with exertion
• () ETT 25 y/o female normal BP (-) RFs
  asymptomatic

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PREDICTIVE VALUE OF ETT RESULTS

• 2. Exercise test results influence predictive
  value
• Example
• Drastically () early onset of ischemic changes
  (low workrate and low heart rate) and/or marked
  ST depression and angina

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Severity of ECG changes (ST depression)

• Amplitude
• Example
• 1mm borderline
• 2mm moderate
• gt2mm severe
• Slope
• Unsloping
• Horizontal
• Downsloping

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EXERCISE TESTING MODALITIES and PROTOCOLS

• Numerous exercise modalities
• Treadmill
• Cycle ergometer
• Steps
• Field tests
• Numerous protocols
• Varying MET increments

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Graded Protocols

• Vary speed (mph) of walking grade (
  inclination) in stages (usually 2-3 min)

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Commonly used treadmill protocols

• (standard) Bruce
• Modified Bruce
• Balke
• Naughton
• Modified Astrand
• Ramp protocols
• Ellestad
• Individualized Ramp tests

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General characteristics of treadmill protocols

• Continuous
• Multistage (graded)
• Start low MET level (2-3 METS)
• Increase workrate 1-3 METS/stage
• Last between 6-15 minutes
• Use large muscle groups
• Do not require significant skill

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Testing protocol should be appropriate for the
person being tested

• Example athlete vs. early post-MI

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TREADMILL PROTOCOLS

• Standard Bruce diverse
• Modified Bruce low-moderate exercise tolerance
  and/or difficulty with gait
• Balke avg. to above avg. fitness levels
• Naughton severely limited exercise tolerance
• RAMP low level to athletic protocols

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• CYCLE VS. TREADMILL EXERCISE TESTS

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1. ADVANTAGES OF CYCLE

• Portable
• Quiet and less upper extremity movement
• Easier to assess BP
• ECG may show less artifact
• Important for persons with difficulty with gait

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2. DISADVANTAGES OF CYCLE

• Underestimate VO2 max and HR max
• (a) Unfamiliarity with cycling
• (b) smaller muscle mass

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3. SENSITIVITY TO DETECT CAD

• No significant difference

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MAXIMAL EXERCISE TESTS

• PREDICTION EQUATIONS USED FOR THE ESTIMATION OF
  VO2 MAX

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Estimation of VO2 max based on actual (direct)
measures of VO2

• Physiologic Principle of Estimating VO2 max
• VO2 is directly related to workrate, therefore,
  estimations of VO2 max can be made on
  standardized tests by determining the highest
  workrate that can be achieved and calculating the
  energy cost of that power output.

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Estimation can result in large potential errors

• Non-Standardization
• Hand held exercise vs. non-hand held
• Population specific equations
• Inappropriate test endpoints
• Familiarization

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Protocol specific equations

• EXAMPLE Bruce treadmill
• Males VO2 max 3.88 .056 x (time-sec)
• Female VO2 max 1.26 .056 x (time-sec)