Chapter 05

1. Chapter 05 C H A P T E R 5 Graded Exercise Testing and Exercise Prescription Keteyian

2. Commonly Used Terms Stress ECG/EKG Regular stress test Cardiac stress test Graded exercise test (GXT) Sign- and symptom-limited GXT (Sx-GXT)

3. Why Learn About Exercise Testing and the Principles and Elements Associated With Conducting Such Testing? Because the same principles and elements are used in conjunction with many similar and more complex diagnostic and prognostic procedures Stress ECG only Cardiopulmonary exercise (CPX) Exercise stress echocardiogram Exercise stress nuclear test or myocardial perfusion imaging (MPI) Pharmacologic stress

4. If Resting ECG Is Abnormal or Patient Cannot Exercise, Consider Another Method to Assess Presence of CAD Stress ECG with imaging ECG plus echocardiogram (stress echo) Allows for assessment of wall motion abnormalities ECG with radionuclide imaging (stress nuclear or MPI) Allows for assessment of distribution of blood flow

5. Another Method to Stress the Myocardium to Reveal Reversible Myocardial Ischemia, Often Used in Patients Who Cannot Exercise Pharmacologic stress with imaging (echo or myocardial perfusion) Beta agonists (e.g., dobutamine) Increase myocardial oxygen consumption by increase in inotropicity and chronotropicity Redistribute blood flow (adenosine, dypiridamole)

6. Cost and accessibility Stress ECG (~$450) < stress echo < stress radionuclide (using exercise or pharmacology to induce stress) < computed tomography with angiogram < cardiac catheterization with angiogram Stress ECG Cost

7. Seven Elements for Graded Exercise Testing Five pretest considerations Appearance and quantification of Sx ECG responses during exercise Blood pressure responses during exercise and recovery HR responses during exercise and recovery Assessment of functional capacity Interpretation of findings (six components) and generation of report

8. Five Pretest Considerations Testing personnel Informed consent General interview and physical examination (includes risk factors and medicine reconciliation) Pretest instructions and subject preparation for ECG 4 h before pretest instruction Immediately before Selection of exercise protocol and modality

9. 1. Testing Personnel Exercise technician (exercise specialist, cardiovascular technician, exercise physiologist) Test supervision and initial interpretation of test data (clinical exercise physiologist, physical therapist, registered nurse, nurse practitioner, physician assistant, physician) Final interpretation of test data (physician) Required versus suggested certifications (ACC, ACSM) (continued)

10. 1. Testing Personnel (continued) Knowledge of indications and contraindications; ability to safely conduct test, select proper protocol and test mode, identify and respond to clinical signs and symptoms appropriately, interpret test responses and findings correctly Safety Risk for combined death or a major event requiring hospitalization = 0.1 to 0.9 per 1,000 tests Death = 0.1 per 1,000 tests

11. 2. Informed Consent A brief explanation of why the test is being done and test procedures Explanation of risks CV: minor and major Orthopedic Metabolic related (diabetes: hypoglycemia, wound care) Patient explains or verbalizes all of these back to test supervisor A “meeting of the minds”

12. 3. General Interview and Examination • This includes determining risk factors and medicine reconciliation.

13. One Objective

14. Indications Assess chest pain and like symptoms to assist in the diagnosis of coronary heart disease or other medical problem Test usefulness is greatest among those with an intermediate (not low and not high) pretest likelihood of having heart disease Identify a patient’s future risk or prognosis Symptoms ST-segment changes Extent and magnitude Time to onset Time to resolution Functional capacity (continued)

15. Indications (continued) Evaluate pacemaker, heart rate, or blood pressure response to exertion Evaluate exercise capacity for return-to-work guidelines and disability determination Determine effect of an intervention Prescribe exercise

16. Absolute Contraindications Myocardial infarction (MI) within prior 2 d or other acute cardiac event Change in ECG suggesting MI or other acute event Unstable angina Symptomatic, severe aortic stenosis Decompensated, symptomatic heart failure (continued)

17. Absolute Contraindications (continued) Acute pulmonary embolism or infarction Acute myocarditis or pericarditis Acute infection Suspected or known ventricular or dissecting aortic aneurysm

18. Relative Contraindications Left main stenosis Moderate valvular stenotic disease Severe arterial hypertension (systolic >200 mmHg or diastolic >11 mmHg) Tachycardia at rest or marked bradycardia (continued)

19. Relative Contraindications (continued) Hypertrophic cardiomyopathy or other forms of outflow tract obstruction Mental or physical impairment that limits ability to exercise or is worsened with exercise High-degree atrioventricular block (Mobitz type II or third degree) Uncontrolled metabolic disease or electrolyte abnormality

20. ACSM Criteria for Who Does and Does Not Need a GXT Before Exercising or Starting an Exercise Program No = low risk Men <45 with less than two CV risk factors Women <55 with less than two CV risk factors Yes = moderate risk Men >44 with two or more CV risk factors Women >54 with two or more CV risk factors Yes = high risk One or more signs or symptoms of CV or pulmonary or metabolic disease Prior history of CV or pulmonary or metabolic disease

21. 4. Subject Preparation Pretest instructions Clothing Comfortable and belted Shoes versus heel-less versus stocking feet Continue medications as prescribed or not and timing of medications Reason for test (diagnostic, prognostic, exercise program) Food and water Substances ETOH Cigarettes Marijuana Other recreational drugs (continued)

22. 4. Subject Preparation (continued) Skin preparation Determine quality of ECG (muscle and motion artifact) Eliminate oils and outer layer of epidermis using chemicals and abrading skin; produce erythema Electrode placement 10 sites: 4 modified limb leads and standard 6 precordial leads Alter site for pacer implant or ICD implant

23. Placement of Electrodes

24. 5. Selection of Protocol and Modality Select protocol Steady state versus ramp Maximal versus submaximal Try to match work rate increments (in estimated METs) to patient capabilities (e.g., walk a flight of stairs) Complete test in 8 to 12 min Use of a common (vs. less common) protocol allows the clinician to compare a patient’s test results to others Repeat testing on a patient should try to use the same protocol, when possible, to allow results to be compared between tests (continued)

25. 5. Selection of Protocol and Modality (continued) Select mode (treadmill, bike, arm ergometer, other) Provide quantified, incremental, graded work Athletes: specificity of testing and training Occupational concerns Accommodate patient needs Orthopedic Body habitus Gait and balance

26. Commonly Used Protocols See table 5.1 on commonly used treadmill and bicycle protocols.

27. Seven Elements for Graded Exercise Testing Pretest considerations Appearance and quantification of Sx ECG responses during exercise Blood pressure responses during exercise and recovery HR responses during exercise and recovery Assessment of functional capacity Interpretation of findings (six components) and generation of report

28. Appearance and Quantification of Symptoms • Maintain regular communication between staff and patient. • At minimum, at the end of each stage assess patient’s rating of perceived exertion (scale 6-19) and any clinical symptoms (excessive dyspnea, claudication, angina). • May need handheld posters for testing done in combination with mouthpiece or mask to measure indirect spirometry. • Accommodate through translation other common languages.

29. Angina, Dyspnea, and Peripheral Vascular Disease Scales See table 5.2 for angina, dyspnea, and peripheral vascular disease scales.

30. Seven Elements for Graded Exercise Testing Pretest considerations Appearance and quantification of Sx ECG responses at rest, during exercise, and in recovery Blood pressure responses during exercise and recovery HR responses during exercise and recovery Assessment of functional capacity Interpretation of findings (six components) and generation of report

31. Benefits of Stress ECG Stress ECG alone can be useful for determining if resting ECG is free of LVH LBBB ST depression >1 mm Pacemaker

32. Figure 5.2

33. Figure 5.3

34. ECG Responses During Exercise Rate Amplitude of waves Normal: decrease in total QRS amplitude Ischemia: increase in QRS amplitude Conduction velocity Normal: PR and QRS durations shorten due to catecholamine-induced increase in conduction velocity Arrhythmia Clinical importance of supraventricular versus ventricular (continued)

35. ECG Responses During Exercise (continued) ST-segment changes Lead V5 most diagnostic for detecting coronary artery disease Criteria for a positive test for ischemia: One or more millimeters of horizontal or downsloping ST depression at 0.08 s past the J point or 1.5 or more mm of upsloping ST depression at 0.08 s past the J point Likelihood of coronary disease increases if more leads are involved, as magnitude of ST depression increases, and if ST depression develops sooner during exercise and/or resolves later in recovery

36. Figure 5.3

37. Seven Elements for Graded Exercise Testing Pretest considerations Appearance and quantification of Sx ECG responses during exercise Blood pressure responses during exercise and recovery HR responses during exercise and recovery Assessment of functional capacity Interpretation of findings (six components) and generation of report

38. Blood Pressure Responses During Exercise Hypertensive response: >210 mmHg at peak Hypertensive response: >90 mmHg at peak Hypotensive response: 10 mmHg decrease in SBP below prior value with evidence of ischemia Decrease below resting SBP Note: Slight decrease in systolic early during exercise or at peak exercise may not indicate a true hypotensive response. Evaluate blood pressure findings within the context of any possible confounding effects of medications (afterload-reducing agents).

39. Blood Pressure Responses During Exercise and Recovery Hypertensive systolic response: >210 mmHg at peak Two- to threefold increased future risk for developing hypertension at rest Abnormal recovery BP response By 3 min into recovery, systolic blood pressure should have dropped by >10% from peak blood pressure; recovery systolic blood pressure at 3 min/peak systolic blood pressure <0.9 (e.g., 140/152 = 0.92)

40. Normal ABI: >0.9 Left arm = 128 Left ankle = 142 ABI = 1.1 Abnormal ABI: <0.9 Left arm = 128 Left ankle = 108 ABI = 0.84 Ankle–Brachial Index

41. Heart Rate Responses During Exercise and Recovery Chronotropic incompetence related to exercise is associated with increased CV events: No beta-blockade taken prior to testing: <85% of age predicted Beta-blockade taken prior to testing: <62% of age predicted Recovery HR = twofold increased future risk for CV events and all-cause mortality if: Decrease in HR <12/min at 1 min Decrease in HR <22/min at 2 min

42. Seven Elements for Graded Exercise Testing Pretest considerations Appearance and quantification of Sx ECG responses during exercise Blood pressure responses during exercise and recovery HR responses during exercise and recovery Assessment of functional capacity Interpretation of findings (six components) and generation of report

43. Assessment of Functional Capacity Exercise duration Estimated METs Peak oxygen uptake Declines by: Healthy, inactive: ~5% to 10% per decade Healthy, active: ~3% to 6% per decade

44. Seven Elements for Graded Exercise Testing Pretest considerations Appearance and quantification of Sx ECG responses during exercise Blood pressure responses during exercise and recovery HR responses during exercise and recovery Assessment of functional capacity Interpretation of findings (six components) and generation of report

45. Interpretation: Six Items to Address A. Chest pain. Typical angina, atypical or noncardiac, none. Note time to onset, test limiting, time to resolution, therapies needed to help resolve? B. ST segment for myocardial ischemia diagnosis. Time of onset, magnitude of change, and time to resolve. Call it positive or negative or nondiagnostic. (continued)

46. Interpretation (continued) C. Heart rate response: Normal (>85% of age predicted, not on beta-blockade) Chronotropic incompetence (<85% of age predicted, not on beta-blockade)—associated with increased future risk for cardiac mortality Normal recovery rate: 12 or more in 1 min, 22 or more in 2 min—associated with increased future risk for cardiac mortality D. Blood pressure response: normal, hypertensive, hypotensive (continued)

47. Interpretation (continued) E. Arrhythmia: State findings. F. Exercise capacity: State peak metabolic equivalent (MET) level and compare to normative data set; state reason for stopping.

48. Possible Major Causes for False-Positive and False-Negative Findings in an ECG Stress Test False positive = positive stress ECG with no significant coronary disease noted with coronary angiography Female gender, digoxin therapy, LBBB, LVH, cardiomyopathy False negative = negative stress ECG with significant coronary disease noted with coronary angiography Failure to reach ischemic threshold (insufficient effort), monitoring of insufficient leads (continued)

49. Possible Major Causes for False-Positive and False-Negative Findings in an ECG Stress Test (continued)

50. In Addition to Six Key Elements of Interpretation to Include in Final Report, Also Consider Including Estimation of Prognosis Using Duke Score Duke score = Exercise time using Bruce protocol – (5 × ST amount of depression) – [4 × (angina score of 0, 1, or 2)] Where: Less than -11 = high risk = >3%/yr mortality -10 to 4 = intermediate risk = >1% to 3%/year mortality >4 = low risk = <1%/yr mortality