TREADMILL TESTING

important non invasive testing

1. TREADMILL TESTING

2. introduction Exercise electrocardiographic testing is among the most fundamental and widely used tests for the evaluation of patients with CVD It is easy to perform , and interpret ; it is flexible and adaptable; and it is reliable, inexpensive , and readily available in hospital or practice settings . The exercise test has been used by clinicians for more than half a century, and its durability can be attributed to its evolution over time

3. INDICATIONS OF EXERCISE TESTING Elicit abnormalities not present at rest Estimate functional capacity Estimate prognosis of CAD Likelihood of coronary artery disease Extent of coronary artery disease Effect of treatment Evaluation and management of patients with a wide variety of cardiovascular conditions, including valvular heart disease, congenital heart diseasearrhythmias , and peripheral arterial disease (PAD). 3

4. METHODS 4 General concerns prior to performing an exercise test include Patient preparation Choosing a test type Choosing a test protocol Patient monitoring Reasons to terminate a test Post test monitoring

5. PRETEST PREPARATION 5 Any history of light headed or fainted while exercising sholud be asked. The physician should also ask about family history and general medical history, making note of any considerations that may increase the risk of sudden death. A brief physical examination should always be performed prior to testing to rule out significant outflow obstruction

6. Preparation for exercise testing include the following- 6 The subject should be instructed not to eat or smoke atleast 2 hours prior to the test . Unusual physical exertion should be avoided before testing. Specific questioning should determine which drugs are being taken. The labeled medications should be brought along so that medications can be identified and recorded. A written informed consent form is usually required. The indication for the test should be known. The supervising physician should be made aware of any recent deterioration in the patient's clinical status. although diagnostic exercise tests in patients without known CAD are best performed by withholding cardioactive medications on the day of the test to better assess for an ischemic response, functional testing in patients with known CAD might best be performed with patients having taken their usual medications to evaluate the effects The test should not be performed on subjects who are markedly hypertensive (e.g., blood pressure > 220/120 mm Hg) or who have unexplained hypotension (e.g., systolic blood pressure < 80 mm Hg) or other contraindications to exercise testing.

7. EXERCISE PROTOCOLS Isotonic or dynamic exercise , isometric or static exercise , resistive (combined isometric and isotonic) exercise. Dynamic protocols are most frequently used to assess cardiovascular reserve, and those suitable for clinical testing should include a low-intensity warm-up phase . In general, 6 to 12 minutes of continuous progressive exercise during which the myocardial oxygen demand is elevated to the patient's maximal level is optimal for diagnostic and prognostic purposes . The protocol should include a suitable recovery or cool-down period.

8. DYNAMIC EXERCISES Arm Ergometry Bicycle Ergometry Treadmill test Walk Test

9. Arm Ergometry Involve arm cranking at incremental workloads of 10 to 20 watts for 2- or 3-minute stages HR & BP responses to a given workload > leg exercise Peak vo2   and peak HR - 70% of leg testing A ramp protocol differs from the staged protocols in that the patient starts at 3 minutes of unloaded pedaling at a cycle speed of 60 rpm. Work rate is increased by a uniform amount each minute, ranging from 5- to 30-W increments. Exercise is terminated if the patient is unable to maintain a cycling frequency above 40 rpm Bicycle Ergometry Involve incremental workloads starting at 25 – 50 watts Lower maximal  VO2  than the treadmill

10. Treadmill Protocols Bruce Modified Bruce Cornell Blake ware Naughton and Weber ACIP (Asymptomatic cardiac ischemia pilot) Modified ACIP

11. 13

12. The Bruce protocol 1949 by Robert A. Bruce, considered the “father of exercise physiology”. Published as a standardized protocol in 1963. gold-standard for detection of myocardial ischemia when risk stratification is necessary .

13. Bruce and Modified Bruce Protocol Bruce:There are 7 stages, but most individuals are unable to complete all of the stages. This protocol starts at 5 METs in stage 1 and then each stage is increased by approximately 2 – 3 METs modified bruce:the first 2 stages occur at workloads of 2.9 and 3.7 METs. Stage three is equal to the first stage (5METs)

14. where grade is expressed as a fraction (e.g., 5% grade = 0.05).    can be converted to METS by dividing by 3.5. The peak    is usually the same regardless of treadmill protocol used; the difference is the rate of time at which the peak    is achieved PROTOCOL USES COMMENTS BRUCE Normally used 3min stages NAUGHTON&WEBER Limited ex tolerance-CCF 1-2 min stages\1 MET increment ACIP Established CAD 2 min stages 1.5-MET increments between stages after two 1-minute warm-up stages. \> linear ↑ in HR & Vo2 MOD-ACIP Short elderly individuals who cannot keep up with a walking speed of 3 mph

15. The 6-Minute Walk Test 17 Used for patients who have marked left ventricular dysfunction or peripheral arterial occlusive disease and who cannot perform bicycle or treadmill exercise. Patients are instructed to walk down a 100-foot corridor at their own pace, attempting to cover as much ground as possible in 6 minutes. At the end of the 6-minute interval, the total distance walked is determined and the symptoms experienced by the patient are recorded.

16. ECG MEASUREMENTS

17. ECG LEAD SYSTEM Mason – Likar modification Adequate skin prepartion Extremity electrodes moved to the torso to reduce motion artifact Arm electrodes - lateral aspects of infraclavicular fossae Leg electrodes -above the anterior iliac crest and below the rib cage

18. Mason –Likar modification It results in Right axis shift Increased voltage in inferior leads May produce loss of inferior Q waves and development of new Q waves in lead aVL Thus, the body torso limb lead positions cannot be used to interpret a diagnostic rest 12-lead ECG

19. Types of ST Segment Displacement In normal persons The PR, QRS, and QT intervals shorten as heart rate increases P amplitude increases PR segment becomes progressively more downsloping in the inferior leads J point or junctional depression will occur

20. J point depression of 2 to 3 mm in leads V 4 to V 6 , with rapid upsloping ST segments depressed approximately 1 mm 80 milliseconds after the J point. The ST-segment slope in leads V 4 and V 5 is 3.0 mV/sec. This response should not be considered abnormal.

21. Types of ST Segment Displacement In patients with myocardial ischemia ST segment usually becomes more horizontal (flattens) as the severity of the ischemic response worsens. With progressive exercise, the depth of ST segment depression may increase, involving more ECG leads, and the patient may develop angina

22. In lead V4 , the exercise ECG result is abnormal early in the test, reaching 0.3 mV (3 mm) of horizontal ST segment depression at the end of exercise. severe ischemic response.

23. The J point at peak exertion is depressed 2.5 mm, the ST segment slope is 1.5 mV/sec, and the ST segment level at 80 msec after the J point is depressed 1.6 mm. “ slow upsloping ” ST segment at peak exercise indicates an ischemic pattern in patients with a high coronary disease prevalence pretest. typical ischemic pattern is seen at 3 minutes of the recovery phase when the ST segment is horizontal and 5 minutes after exertion when the ST segment is downsloping.

24. abnormal at 9:30 minutes ES test and resolves in the immediate recovery phase. pattern in which the ST segment becomes abnormal only at high exercise workloads and returns to baseline in the immediate recovery phase may indicate a false-positive result in an asymptomatic individual without atherosclerotic risk factors.

25. Types of ST Segment Displacement In the immediate postrecovery phase ST segment displacement may persist, with downsloping ST segments and T wave inversion, gradually returning to baseline after 5 to 10 minutes Ischemic response ---only in the recovery phase Occur in 10 percent of patients Prevalence is higher in asymptomatic populations compared with those with symptomatic CAD

26. MEASUREMENT OF ST SEGMENT DISPLACEMENT True isoelectric point ----TP segment For purposes of interpretation--- PQ junction is usually chosen as the isoelectric point Abnormal response The development of 1 mm or greater of J point depression with a relatively flat ST segment slope (<1 mV/sec ) depressed greater than or equal to 0.10 mV 80 msec after the J point (ST 80) in three consecutive beats with a stable baseline

27. ECG changes during stress test

28. Ischemic exercise-induced ECG

29. MEASUREMENT OF ST SEGMENT DISPLACEMENT When the ST 80 measurement is difficult to determine at rapid heart rates (e.g., >130 beats/min), the ST 60 measurement should be used. The ST segment at rest may occasionally be depressed. When this occurs, the J point and ST 60 or ST 80 measurements should be depressed an additional 0.10 mV or greater to be considered When the degree of resting ST segment depression is 0.1 mV or greater, the exercise ECG becomes less specific, and myocardial imaging modalities should be considered

30. MEASUREMENT OF ST SEGMENT DISPLACEMENT In early repolarization Normal response---Resting ST segment elevation returns to the PQ junction Magnitude of exercise-induced ST segment depression should be determined from the PQ junction and not from the elevated position of the J point before exercise

31. MEASUREMENT OF ST SEGMENT DISPLACEMENT Localization of site of myocardial ischemia ST segment depression do not localize the site of myocardial ischemia and which coronary artery is involved ST segment elevation is relatively specific for the territory of myocardial ischemia and the coronary artery involved.

32. UPSLOPING ST SEGMENTS Normal response J point depression Rapid upsloping ST segment (>1 mV/sec) depressed less than 1.5 mm a t ST 80 Abnormal response Depression of ST segment > 1.5 mm at ST80 Patients with a high CAD prevalence--- abnormal. Asymptomatic or with a low CAD prevalence--- less certain.

33. ST SEGMENT ELEVATION ST segment elevation may occur in an infarct territory where Q waves are present in a noninfarct territory. Abnormal response 1 mm elevation at ST60 for 3 consecutive beats with a stable baseline.

34. ST SEGMENT ELEVATION ST segment elevation in leads with abnormal Q waves Occur in 30% of anterior MI & 15% of inferior MI Have a lower ejection fraction greater severity of resting wall motion abnormalities worse prognosis. not a marker of more extensive CAD rarely indicates myocardial ischemia.

35. ST SEGMENT ELEVATION ST segment elevation in leads without Q waves Indicates transmural myocardial ischemia caused by coronary vasospasm or a high-grade coronary narrowing Occurring in a 1 percent of patients with obstructive CAD. Site of ST segment elevation is relatively specific for the coronary artery involved

36. ST SEGMENT ELEVATION

37. T WAVE CHANGES Pseudonormalization of T waves T-waves inverted at rest and becoming upright with exercise Nondiagnostic finding --- in low CAD prevalence populations In rare instance--- marker for myocardial ischemia

38. Pseudonormalization of T waves

39. OTHER ECG MARKERS Changes in R wave amplitude Relatively nonspecific and are related to the level of exercise performed In LVH the ST segment response cannot be used reliably to diagnose CAD U wave inversion may occasionally be seen in the precordial leads at heart rates of 120 beats/min Relatively specific and relatively insensitive for CAD

40. ST/HR SLOPE MAESUREMENTS HR adj of ST seg dep - ↑ sensitivity ST/HR slope of 2.4 mV/beats/min-abnormal >6mV/beats/min -3 vessel disease CORNELL protocol-gradual inc in HR ST seg /HR index - av change of ST depression with HR through out the course of exercise test > 1.6 -abnormal

41. NONELECTROCARDIOGRAPHIC OBSERVATIONS

42. Blood Pressure Normal Exercise response SBP - Increase to 160 to 200 mm HG DBP - Does not change significantly In LV dysfunction (or) an excessive reduction in systemic vascular resistance Failure to increase SBP> 120 mm HG (or) Sustained decrease > 10 mm HG repeatable within 15 seconds (or) Fall in SBP below standing rest values

43. Exertional Hypotension Ranges from 3 to 9 % Higher in patients with TVD (or) Left main CAD Cardiomyopathy Cardiac arrhythmias Vasovagal reactions LVOT Obstruction On Antihypertensive drugs Hypovolemia Prolonged Vigorous Exercise

44. Work Capacity Limited work capacity Associated with increased risk of cardiac events in known(or) suspected CAD In estimating functional capacity, the amount of work performed (or exercise stage achieved ) should be the parameter measured and not the number of minutes of exercise

45. 1-MET ↑ in exercise capacity, the survival improved by 12 % Age-adjusted relative risks of all-cause mortality by quintile of exercise capacity in 2534 subjects with a normal exercise test result and no history of cardiovascular disease and 3679 subjects with an abnormal exercise test result or history of cardiovascular disease. The mean duration of follow-up was 6.2 ± 3.7 years. Quintile 5 was used as the reference category. For each 1-MET increase in exercise capacity, the survival improved by 12 percent (From Myers J, Prakash M, Froelicher V, et al: Exercise capacity and mortality among men referred for exercise testing. N Engl J Med 346:793, 2002 N Engl J Med 346:793, 2002.)

46. Cumulative 20-year survival rates in 6749 black and 8911 white male U.S. veterans with and without cardiovascular disease. Survival is significantly reduced with each decrement in peak aerobic capacity. The relationship was similar for those with and without cardiovascular disease and for blacks and whites. (From Kokkinos P, Myers J, Kokkinos JP, et al: Exercise capacity and mortality in black and white men. Circulation 117:614, 2008.)

47. Heart rate response Sinus rate increases progressively with exercise. Inappropriate increase in heart rate at low work loads - Atrial fibrillation Physically deconditioned Hypovolumic Anemia Marginal left ventricular function When the heart rate fails to incraese appropriately with exercise it is associated with adverse prognosis

48. Maximum Heart Rate The maximum heart rate with exercise is a fundamental physiologic parameter that provides the clinician relevant information concerning the intensity of exercise, the adequacy of the exercise test, the effect of medications that influence heart rate, the poten - tial contribution to exercise intolerance, and the patient’s progno - sis The maximum achievable heart rate ( HRmax ) is unique for each patient but can be estimated by using regression equations that adjust for the patient’s age. The most familiar equation, which was developed principally in middle-aged men, is HRmax = 220 − Age Although easy to apply and calculate, there is considerable variability with this equation, especially in patients with CAD who are taking beta blockers. Newer equations have been proposed to replace the 220 − age rule to generate the age-predicted maximum heart rate: Men: HRmax = 208 − (0.7 × Age) Women: HRmax = 206 − (0.88 × Age) CAD with beta blockers: HRmax = 164 − (0.7 × Age)

49. Sub-Maximal Exercise when the peak heart rate achieved is below the age-predicted maximum heart rate. An inadequate study is defined by failure to achieve a predefined goal, such as 85% of the age-predicted maximum heart rate . If a patient without known CAD has an inadequate study, the term nondiagnostic study is often applied. As with all things, this “ nondiagnostic ” status is relative.

50. 52 Chronotropic incompetence is determined by decreased heart rate sensitivity to the normal increase in sympathetic tone during exercise and is defined as inability to increase heart rate to atleast 85 percent of age predicted maximum. Heart rate reserve is calculated as follows – % HRR used = ( HR peak - HR res ) / (220-age- Hr res )

51. Chronotropic index Refers to heart rate increment per stage of exercise that is below normal. Indicates Autonomic dysfunction Sinus node disease Drug therapy(beta blockers). Myocardial ischemic response When less than 80%, long term mortality is increased

52. Heart Rate Recovery(HRR) Abnormal HRR refers to a relatively slow deceleration of heart rate following exercise cessation Reflects decreased vagal tone - associated with increased mortality When the postexercise phase includes an upright cool-down, a value of 12 beats/min or less is abnormal . For patients undergoing stress echocardiography or otherwise assuming a supine position immediately after exercise, a value of 18 beats/min or less is abnormal. When HRR is measured 2 minutes into recovery, a value of 22 beats/min or less is abnormal.

53. The prognostic value of abnormal HRR is independent of the exercise level attained , beta blocker usage, severity of CAD, left ventricular function , chronotropic incompetence, Duke treadmill score, and presence of exercise-induced angina or ischemic electrocardiographic abnormalities . Abnormal HRR is associated with increased abnormal and high-risk myocardial perfusion scans, even in patients without exercise test results that would normally warrant further testing

54. Rate-Pressure Product Heart rate x Systolic BP Product Indirect measure of myocardial oxygen demand increases progressively with exercise used to characterize cardiovascular performance Normal - 20 to 35 mm HG x beats/m x 10 -3 In CAD - < 25 mm HG x beats/m x 10 -3

55. Chest discomfort It occurs usually after the onset of ischemic ST segment depression In some patients , it may be the only signal of obstructive CAD In CSA , Chest discomfort occurs less frequently than ischemic ST segment depression

56. Diagnostic Use of Exercise Testing 66% 53% 81% 86% Multivessel CAD Left main or TVD --- 25-71% LAD>RCA>LCx SVD 77% 68% In CAD (General) Specificity Sensitivity Patients

57. Approximately 75% to 80% of the diagnostic information on exercise-induced ST-segment depression in patients with a normal resting ECG is contained in leads V 4 to V 6 . The exercise ECG is less specific when patients in whom false-positive results are more common are included, such as those with valvular heart disease, left ventricular hypertrophy, marked resting ST segment depression, or digitalis therapy.

58. Noncoronary causes of ST segment depression Severe aortic stenosis Severe hypertension Cardiomyopathy Anemia Hypokalemia Severe hypoxia Digitalis use Sudden excessive exercise

59. Noncoronary causes of ST segment depression Glucose load Left ventricular hypertrophy Hyperventilation Mitral valve prolapse Interventricular conduction disturbance Preexitation syndrome Severe volume overload (aortic,mitral regurgitation) Supraventricular tacyarrhythmias

60. Bayes’ Theorem Incorporates pretest risk of disease & sensitivity and specificity of test to calculate post-test probability of CAD Clinical information and exercise test results are used to make final estimate about probability of CAD Diagnostic power maximal when pretest probability of CAD is intermediate (30% to 70%)

61. Pretest Probability Based on the pat's h/o ( age, gender, chest pain ), phy ex and initial testing, and the clinician's experience. Typical or definite angina →pretest probability high - test result does not dramatically change the probability.

62. Classification of chest pain Typical angina Atypical angina Noncardiac chest pain Substernal chest discomfort with characterstic quality and duration Provoked by exertion or emotional stress Relieved by rest or NTG Meets 2 of the above characteristics Meets one or none of the typical characteristics

63. Pre Test Probability of Coronary Disease by Symptoms, Gender and Age

64. INTERMEDIATE CATEGORY AGE GROUP GENDER & SYMPTOMS 30-39 YEARS M& F + TYPICAL ANGINA M + ATYPICAL/ PROBABLE ANGINA 40-49 YEARS F + TYPICAL ANGINA M + ATYPICAL/ NON ANGINAL CP 50-59 YEARS F+ TYPICAL ANGINA M&F + ATYPICAL NAGINA M+ NON ACP 60-69 YEARS M& F+ ATYPICAL/PROB ANGINA M&F + NACP

65. EXERCISE PARAMETERS ASSOCIATED WITH ADVERSE PROGNOSIS AND MULTIVESSEL CAD Duration of symptom-limiting exercise < 5 METs    Abnormal BP response Angina pectoris at low exercise workloads    ST-depression ≥ 2 mm - starting at <5 METs down sloping ST - involving ≥5 leads, - ≥5 min into recovery    Exercise-induced ST- elevation (aVR excluded)    Reproducible sustained or symptomatic VT

66. . Exercise Testing in Determining Prognosis Asymptomatic population Prevalence of abnormal TMT in asymptomatic middle aged men - 5-12%. Risk of developing a cardiac event- approximately nine times when test abnormal Future risk of cardiac events is greatest if test strongly positive or with multiple risk factors Appropriate asymptomatic subjects for test - estimated annual risk > 1 or 2% per year

67. Prognostic Value of the Exercise Electrocardiogram Prognostic Variables The strongest predictor of prognosis derived from the exercise test is exercise capacity. The weakest predictor is ST-segment depression . All other variables, such as the heart rate achieved, HRR, blood pres - sure response, ventricular arrhythmias, and exercise-induced angina, fall between these two extremes. This prognostic hierarchy is similar in both men and women.

68. Symptomatic patients Exercise ECG should be routinely performed in patients with chronic CAD before CAG Patients with good effort tolerance (>10 METS) have excellent prognosis regardless of anatomical extent of CAD. Provides an estimate of functional significance of CAG documented coronary stenoses

69. RISK ASSESSMENT AND PROGNOSIS in PATIENTS WITH SYMPTOMS OR PRIOR HISTORY OF CAD CLASS INDICATION ACC/AHAGuidelines 2002 I  1. Patients undergoing initial evaluation   Exceptions a .  Preexcitation syndrome    b. Electronically paced ventricular rhythm    c. >1 mm of ST-segment depression at rest    d. Complete left bundle branch block   2. Patients after a significant change in cardiac symptoms 3. Low-risk unstable angina patients 8 to 12 hr after presentation who have been free of active ischemic or heart failure symptoms 4. Intermediate-risk unstable angina patients 2 to 3 days after presentation who have been free of active ischemic or heart failure symptoms III  Patients with severe comorbidity likely to limit life expectancy or prevent revascularization

70. Duke tread mill score Developed by Mark and co-workers Provide survival estimates based on results from exercise test Provides accurate prognostic & diagnostic information Adds independent prognostic information to that provided by clinical data & coronary anatomy Less effective in estimating risk in subjects > 75

71. Duke tread mill score - RISK Score Risk 5 yr survival % CAD > 5 Low risk 97 Nil / SVD - 10 to +4 Moderate risk 91 < -11 High risk 72 TVD/LMCA

72. Duke tread mill score Exercise time - (5 ˣ ST deviation) - (4 ˣ treadmill angina index) Angina index 0-if no angina 1-if typical angina occurs during exercise 2-if angina was the reason pt stopped exercise

73. SEX SPECIFIC SCORES

74. POST MI STATUS Since 2002, when the last full set of exercise testing guidelines was updated,21 treatment of myocardial infarction and evaluation of post– myocardial infarction patients have evolved greatly. In those guidelines, exercise testing carried class I indica - tions before hospital discharge (sub- maximal 4 to 7 days), 14 to 21 days after discharge (symptom limited if not performed before discharge), and 3 to 6 weeks after discharge (symptom limited if predischarge submaxi - III mal performed). These recommendations were based largely on the then existing ACC/AHA guidelines for the management of acute myo - cardial infarction. In this setting the exercise test was found to be safe, with a reported mortality rate of 0.03% and a nonfatal event rate of 0.09%.

75. Present clinical environment, realistic goals of exercise testing in the post–myocardial infarction setting, whenever it is per- formed, should be threefold: to provide (1) a functional evaluation to guide the exercise rehabilitation prescription, (2) a basis for advice concerning return to work and other physical activities, and (3) an evaluation of present therapy.