Treadmill Exercise ECG Test. Pai-Feng Kao MD Taipei Medical University-Wan Fang Hospital Date:

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1 Treadmill Exercise ECG Test Pai-Feng Kao MD Taipei Medical University-Wan Fang Hospital Date:

2 Foam Cells Atherosclerosis Timeline Fatty Streak Intermediate Lesion Atheroma Fibrous Plaque Complicated Lesion/ Rupture From First Decade Endothelial Dysfunction From Third Decade From Fourth Decade Adapted from Pepine CJ. Am J Cardiol. 1998;82(suppl 104).

3 Coronary Artery Disease a chronic disorder clinically defined phases: asymptomatic stable angina progressive angina acute coronary syndrome unstable angina, NQMI, acute MI

4 Thrombus Formation and ACS Plaque Disruption/Fissure/Erosion Thrombus Formation Old Terminology: UA NQMI STE-MI New Terminology: Non-ST-Segment Elevation Acute Coronary Syndrome (ACS) ST-Segment Elevation Acute Coronary Syndrome (ACS)

5 Schema of the ischemic cascade

6 Evaluation and Diagnosis In patients presenting with chest pain detailed symptom history focused physical examination directed risk-factor assessment Estimate the probability of significant CAD (i.e., low, intermediate, high)

7 Pretest Likelihood of CAD in Symptomatic Patients According to Age and Sex (Combined Diamond/Forrester and CASS Data) Nonanginal Age Chest Pain Atypical Angina Typical Angina Years Men Women Men Women Men Women *Each value represents the percent with significant CAD on catheterization

8 Probability Estimate the Duke and Stanford models The likelihood of disease for women <55 years old with atypical angina and no risk factors is < 10 %; but if diabetes, smoking and hyperlipidemia are present, the likelihood jumps to 40 %. Am J Med 1983;75: ; Am J Med 1990;89:7-14 Ann Intern Med 1993;118:81-90

9 12 Lead Resting ECG should be recorded in all patients with symptoms suggestive of angina pectoris normal in 50% of patients a normal ECG does not exclude severe CAD; however, it does imply normal LV function with favorable prognosis

10 Clinical Assessment Recommendations for Stress test Electrocardiography Echocardiography or Radionuclide Angiography

11 Treadmill exercise ECG test

12 Stress Thallium 201 scan

13 Stress echocardiography

14 Multislice CT

15 Coronary angiography

16 Stress Tests - cost issues exercise ECG is least costly stress echocardiography stress SPECT myocardial imaging coronary angiography 1X 2X 5X 20X

17 Comparison of Stress Tests meta-analysis on 44 articles (published between 1990 and 199 Sensitivity Specificity ECG 52% 71% Echocardiography 85% 77% Scintigraphy 87% 64% not adjusted for referral bias, exercise echocardiography had significantly better discriminatory power than exercise myocardial perfusion imaging JAMA 1998;280:913-20

18 Exercise Stress Tests stepwise strategy Exercise ECG simplicity, lower cost and familiarity the initial test in patients who are not taking digoxin, have a normal rest ECG, and are able to exercise Stress-imaging techniques for patients with widespread rest ST depression (>1 mm), complete left bundle-branch block, ventricular paced rhythm or preexcitation

19 Ischemic Heart Disease and Resting Electrocardiography

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24 Chest Pain and Ischemic Heart Disease

25 Exercise

26 Exercise Physiology Acceleration of ventricular rate Vagal withdrawal Increase alveolar ventilation Sympathetic vasoconstriction- Increased venous return Increase cardiac output

27 Treadmill Exercise Test

28 Introduction The evaluation of chest pain can be very difficult. It is possible to have a normal resting ECG with considerable narrowing of the coronary arteries. Exercise testing was developed in the 1950s with the Bruce protocol published in It is now a well established technique.

29 Exercise ECG testing can be used in the following circumstances: Assessing a clinical diagnosis of angina Risk stratification after myocardial infarction Risk stratification in patients with hypertrophic cardiomyopathy Evaluation of revascularisation procedures or drug treatment Evaluation of exercise tolerance and cardiac function Assessment of cardiopulmonary function in patients with dilated cardiomyopathy or heart failure Assessment of treatment for arrhythmia Assessment of asymptomatic people in high risk occupations like airline pilots.

30 Cardiopulmonary exercise test in a healthy 53-year-old man using the Bruce protocol.

31 Metabolic equivalent MET: Resting V o for 70-Kg 40 y/o male 2 1 MET= 3.5ml/min/kg of body weight

32 Estimated oxygen cost of bicycle ergometer and selected treadmill protocols

33 The Bruce protocol is very widely used and has been extensively validated. There are 7 stages of 3 minutes each so that a complete test takes 21 minutes.

34 A modified Bruce protocol is used for exercise testing within one week of myocardial infarction and for those who are old and frail or expected to have poor exercise tolerance for other reasons. It starts at a lower work level and so takes longer to achieve the required heart rate. This would make the patient more susceptible to fatigue before achieving the required rate but it seems that judicious use of either the Bruce or modified Bruce protocols gives satisfactory results.

35 Absolute Contraindications to Exercise Testing Acute myocardial infarction (within 2 d) High-risk unstable angina* Uncontrolled cardiac arrhythmias causing symptoms or hemodynamic compromise Symptomatic severe aortic stenosis Uncontrolled symptomatic heart failure Acute pulmonary embolus or pulmonary infarction Acute myocarditis or pericarditis Acute aortic dissection AHA/ACC Guideline 2002

36 Relative Contraindications for Treadmill Testing Left main coronary stenosis Moderate stenotic valvular heart disease Electrolyte abnormalities Severe arterial hypertension Tachyarrhythmias or bradyarrhythmias Hypertrophic cardiomyopathy and other forms of outflow tract obstruction Mental or physical impairment leading to inability to exercise adequately High-degree atrioventricular block AHA/ACC Guideline 2002

37 Complications of Treadmill Testing Brady / Tachyarrythmias AMI / Sudden Death CHF / Shock MSK Trauma / Fatigue / Malaise

38 Safety and Risks of Exercise testing Nonselective patient population Mortality <0.01% Morbidity <0.05% Survey of tests for within 4 weeks of AMI Mortality <0.03% 0.09% had nonfatal reinfarction or resuscitated from cardiac arrest Major complication 2X in symptom-limited protocol than low-level protocol

39 Treadmill Testing: Procedures Physiology Exercise creates increase CO Four to six fold increase from rest at peak CO increase by increase HR and PB and decreased vagal tone HR affected by Age, sex, motivation, habitus, blood volume, health SBP increases with exercise DBP stays same or slightly decreases Hypotension ominous sign Outflow obstruction, ventricular dysfunction or ischemia

40 Treadmill Testing: Procedures Equipment Treadmill or cycle ergometer Cycle has major pitfall of rapid fatigue of quadriceps in older patients Most studies use treadmill Handrails, Rest Area Assistant, Supervisor Resuscitation Equipment

41 Treadmill Testing: Procedures Preparation Fast 3 hours prior / dress appropriately footwear Medications reviewed by physician prior History and physical prior regarding change in disease CHF; valvular disease; onset of unstable angina; bronchospasm Consent Baseline supine and upright ECG

42 Treadmill Testing: Procedures Protocols Most diagnostic and prognostic studies based on Bruce protocol Seven phases Change in grade and speed every 3 minutes Correlation with METS Large incremental stages Not correlated for height / weight / stride Ideal protocol lasts 6-12 minutes and adjusts for patients ability Others include Naughton, McHenry, USAF, Blake

43 The aim of the exercise is for the patient to achieve the target heart rate of 85% of maximum.

44 Ideally, for an adequate test the patient should achieve 85% of maximum heart rate. Maximum heart rate is calculated as 220- age in years for men and 210- age for women.

45 Blood pressure is measured before starting and at the end of each stage of exercise. Blood pressure may fall or be stable during the early stages. Systolic blood pressure should increase as the exercise level rises. Up to 225 mm Hg is normal, although athletes can have higher levels. Diastolic pressure usually falls slightly.

46 Simple Estimation of Ex Intensity Low Intensity: 3-5 METs Moderate Intensity: 4-7 METs High Intensity: 8-12 METs

47 HR Responses During Exercise

48 Treadmill Testing: Procedures Borg Scale Correlation of scale to actual fatigue 6-20 grade scale for exertion 10 grade scale for exertion now adopted 0 nothing 9 very strong 10 very, very strong Continues to be a clinical assessment of fatigue by technician (skilled) and supervisor Mainly used as repetitive assessment tool in rehab Borg. Sports and Exercise

49 Treadmill Testing: Procedures Measurements ST depression / elevation (60-80 ms; J point changes) ST slope (downsloping worse than horizontal) Duration of changes into recovery Exercise induced arrhythmias Peak HR / BP Total Duration Exertional hypotension Angina Other exercise induced symptoms

50 Absolute Indications for Terminating Exercise Testing Drop in systolic blood pressure of >10 mm Hg Moderate to severe angina Increasing nervous system symptoms (eg, ataxia, dizziness, or near-syncope) Signs of poor perfusion (cyanosis or pallor) Technical difficulties in monitoring ECG or systolic blood pressure Subject s desire to stop Sustained ventricular tachycardia ST elevation ( 1.0 mm) in leads without diagnostic Q-waves (other than V1 or avr)

51 Relative Indications for Terminating Exercise Testing Drop in systolic blood pressure of ( 10 mm Hg from baseline blood pressure despite an increase in workload, in the absence of other evidence of ischemia ST or QRS changes such as excessive ST depression (>2 mm of horizontal or downsloping ST-segment depression) or marked axis shift Arrhythmias other than sustained ventricular tachycardia, including multifocal PVCs, triplets of PVCs, supraventricular tachycardia, heart block, or bradyarrhythmias Fatigue, shortness of breath, wheezing, leg cramps, or claudication Development of bundle-branch block or IVCD that cannot be distinguished from ventricular tachycardia Increasing chest pain Hypertensive response*

52 Interpretation of Exercise ECG

53 Measurement of STsegment displacement Isoelectric point: PQ junction-j point Abnormal response: ST-segment depressed 0.10mV 60 to 80 msec after the J point in 3 consecutive beats with a stable baseline

54 Magnified ischemic exercise induced electrocardiographic pattern. Three consecutive complexes with a relatively stable baseline are selected. The PQ junction (1) and J point (2) are determined; the ST 80 (3) is determined at 80 msec after the J point.

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58 Criteria for a positive exercise test: Conventional criteria Horizontal or downsloping ST segment depression 1mm Upsloping ST segment depression 1.5mm with a duration 0.08 sec

59 J point depression of 2 to 3 mm in leads V 4 to V 6 with rapid upsloping ST segments depressed approximately 1mm 80msec after the J point.

60 Bruce protocol. lead V 4, the exercise electrocardiographic ( ECG ) result is abnormal early in the test, reaching 0.3mV (3mm) of horizontal ST segment depression at the end of exercise.

61 Bruce protocol. In this type of ischemic pattern, the J point at peak exertion is depressed 2.5mm, the ST segment slope is 1.5mV/sec, and the ST segment level at 80msec after the J point is depressed 1.6mm.

62 Bruce protocol. The exercise electrocardiographic ( ECG ) result is not yet abnormal at 8:50 minutes but becomes abnormal at 9:30 minutes

63 Illustration of eight typical exercise electrocardiographic ( ECG ) patterns at rest and at peak exertion.

64 A 48-year-old man with several atherosclerotic risk factors and a normal resting electrocardiographic ( ECG ) result developed marked ST segment elevation associated with angina.

65 Pseudonormalization of T waves in a 49-year-old man referred for exercise testing. The patient had previously been seen for typical angina. The resting electrocardiogram in this patient with coronary artery disease shows inferior and anterolateral T wave inversion, an adverse long-term prognosticator.

66 A 67-year-old man with ischemic cardiomyopathy referred for exercise testing had a left bundle branch block and first-degree atrioventricular (AV) block on the resting ECG.

67 A 75-year-old woman with chronic atrial fibrillation and a 6-month history of atypical chest pain underwent mitral valve repair 1 year before testing, at which time nonobstructive coronary disease was noted.

68 A 58-year-old hypertensive diabetic man with prior history of cigarette smoking was referred for evaluation of dyspnea and early fatigability during exercise. The abnormal 2.5 to 3 mm downsloping ST segment depression in lead II during the LBBB is nondiagnostic for coronary artery disease because of the conduction disturbance.

69 Exercise -induced ST segment depression is noted in leads V 2 to V 3 (arrows) in this patient with a resting right bundle branch block (RBBB) pattern. Exercise - induced horizontal or downsloping ST segment responses in the early anterior precordial leads (V 1 through V 4 ) are common in patients with RBBB and are secondary to the conduction disturbance. The presence of this finding in leads V 1 through V 4 is not diagnostic of obstructive coronary disease.

70 61-year-old man with atypical angina and a hiatal hernia was referred for diagnostic exercise testing. The test was stopped because of dyspnea. The standing resting ECG shows an intermittent Wolff-Parkinson-White pattern (arrows).

71 Treadmill Testing: Results Prognostic Duke Score Time in minutes ST depression in mm Type of pain 0 - none 1 typical anginal pain limited by time / fatigue / other 2 limiting anginal pain

72 Treadmill Testing: Results Duke Score = Time(m) 4X Angina 5X depression(mm) Score: 5 & above low risk 4 to 9 intermediate risk -10 & below high risk

73 Survival According to Risk Groups Based on Duke Treadmill Score 4 -Year Annual Risk Group (Score) Total Survival Mortality Low ( +5) 62% 99% 0.25% Moderate (-10 to +4) 34% 95% 1.25% High (< -10) 4% 79% 5.00% N Engl J Med 1991;325:849-53

74 Use of Exercise Test Results in Patient Management predicted average recommended risk score annual mortality treatment low <1% per year medical therapy intermediate 1% to 3% cardiac catheterization exercise imaging study high-risk score >3% per year cardiac catheterization * <5% pt with low-risk treadmill score will be identified as high risk after imaging * those with known LV dysfunction should have cardiac catheterization

75 Treadmill Testing: Results Exercise Capacity Reasonable to Use exercise testing for Surgical patients recovering from Congenital repair Valvular replacement Cardiac transplant CHF DM CRF Chronic Lung Disease No exercise induced symptoms AHA Guidelines Carliner et al. Am J Card. 1985

76 Treadmill Testing: Results Exercise Capacity and Prognostication 1575 men; mean age 43 Failure to achieve 85 % of age predicted maximum heart rate associated with increase in death of 1.84 Extrapolation techniques used Lauer and Fletcher. Circulation

77 Treadmill Testing: Results Evaluation of Medical Therapy Look for improvement of exercise capacity to previous before angina or ST depression Evaluation of Valvular Disease Strict guideline for evaluation of AS Evaluation of Dysrrythmias PVC, Sick sinus Syndrome Pre-operative Anesthetists 2 nd largest user of stress test for evaluation of patient for non cardiac surgery AHA Guidelines

78 Notable Studies Exercise Hypotension Looking at SBP drop with exercise Looked at 0, 10, 20 drop of SBP Drop of 20 associated with increased PPV of at least 50% Left Main or Triple Vessel Disease Dubach et al. Circulation. 1989

79 Notable Studies Variables 3974 men Kaplan-Meier regression Four variables predict mortality within 5 year Rate of change of rate-pressure product Age > 65 Maximum MET <5 LVH on ECG Prakash et al. Am Heart J. 2001

80 Notable Studies METS Found that sensitivity increases if MET >7 Also found that METS achieved may be a stronger variable than rate-pressure product High heart rate at low MET (<5) level carries adverse prognosis Ramamurthy et al. Chest

81 Notable Studies Risk Factors Multiple Risk Factor Intervention Trial 12,866 participants Those with ST changes on Stress Treadmill benefit to greater degree with risk factor modification than controls. Am J Cardiol. MRFIT

82 Notable Studies Women Large number of false positives Mitral valve prolapse; Higher incidence atypical chest pain Hormonal, esp. estrogen mimickery of digoxin Ventilation Responses and Metabolic Alkalosis Curzen. Heart women Compared with coronary angiography 42 false positives & 31 false negatives (36 % of total) Increase false positives correlated with Increasing age to 52 Increasing coronary risks to 3

83 Notable Studies Early Stress Testing 276 low risk patients Stress test within 48 hours Similar prognostication numbers 0.5 % event rate Additional variables over 6 months 15% less ED visits 30% fewer admission Polanczyk. Am J Card

84 Noncoronary Causes of ST Segment Depression Severe aortic stenosis Severe hypertension Cardiomyopathy Anemia Hypokalemia Severe hypoxia Digitalis Sudden excessive exercise Glucose load Left ventricular hypertrophy Hyperventilation Mitral valve prolapse Intraventricular conduction disturbance Preexcitation syndrome Severe volume overload (aortic, mitral regurgitation Supraventricular tachyarrhythmias

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87 This is a non-invasive screening test rather than a "gold standard". The following findings suggest high probability of coronary artery disease Horizontal ST segment depression of <2 mm Down-sloping ST segment depression Early positive findings within 6 minutes Persistence of ST depression for more than 6 minutes after stopping ST segment depression in 5 or more leads Hypotension with exercise

88 Exercise Parameters Associated with an Adverse Prognosis and Multi-vessel Coronary Artery Disease Duration of symptom-limiting exercise (< 5 METs) Failure to increase systolic blood pressure 120 mm Hg, or a sustained decrease 10 mm Hg, or below rest levels, during progressive exercise ST segment depression 2 mm, downsloping ST segment, starting at < 5 METs, involving 5 leads, persisting 5 minutes into recovery Exercise-induced ST segment elevation (avr excluded) Angina pectoris at low exercise loads Reproducible sustained (> 30 sec) or symptomatic ventricular tachycardia Acute systemic illness (pulmonary embolism, aortic dissection)

89 References Heart disease 7th edition ACC/AHA 2002 Guideline Update for Exercise Testing Exercise Treadmill Testing Dr. Peter Krampl 2001 Exercise ECG Testing: EMIS Last Updated: 22 Nov 2006 Review Date: 21 Nov 2008

90 Thanks For Your Attention