1. STRESS ECG AND STRESS ECHOCARDIOGRAPHY
Giuseppe Biondi Zoccai
Division of Cardiology, University of Turin, Turin, Italy
Meta-analysis and Evidence-based medicine Training in Cardiology (METCARDIO), Ospedaletti, Italy

2. LEARNING GOALS Scope of the problem Stress ECG Stress echocardiography
Reconciling the evidence

3. LEARNING GOALS Scope of the problem Stress ECG Stress echocardiography
Reconciling the evidence

4. FINDING AN APPROPRIATE DIAGNOSTIC LEVEL

5. FINDING AN APPROPRIATE PROGNOSTIC LEVEL

6. DIAGNOSTIC AND PROGNOSTIC WORK-UP OF SUSPECTED CORONARY HEART DISEASE
Clinical history
Physical examination
Resting ECG
Resting echocardiography
Stress ECG
Stress echocardiography
Stress nuclear scan
Coronary CT
Coronary angiography ….

7. EFFECTIVE RADIATION DOSES
Picano, Am J Med 2003

8. CORONARY STEAL PHENOMENON
Picano, Circ 1998

9. CORONARY STEAL PHENOMENON
Picano, Circ 1998

10. THREE STATES OF THE SODIUM CHANNEL AND THE NORMAL SODIUM CURRENT (INa)
Late INA Slides from CVT CARE Meeting in Miami
4/20/2017
THREE STATES OF THE SODIUM CHANNEL AND THE NORMAL SODIUM CURRENT (INa)
Sodium Current
Late
Na+
Na+
Na+
Peak
Resting
Closed
Activated
Inactivated
out
Na+
Na+ in
[Na]
140 mM
Na+
Na+
~ 10mM
Na+
Na+
Ca++
Ca++ in
Ca++
Ca++
Na+
Ca++
Ca++
out
Na+/Ca++
Exchanger
Na+
Ca++
Confidential, Please Do Not Copy and/or Distribute

11. ISCHEMIA INDUCED EFFECTS ON LATE INa AND INTRACELLULAR CALCIUM
Excess Calcium:
Electrical instability
Contractile dysfunction
ECG changes
Sodium Current
Late
Na+
Impaired
Inactivation
Peak
Na+
Na+
out
Na+
Na+
Na+
Na+
Na+
Ca++ in
Na+
Na+
Na+
Na+
Ca++
Ca++
Ca++
Ca++
Ca++
Ca++
Ca++ in
Ca++
Ca++
Ca++
Na+
Ca++
Ca++
Ca++
Ca++
out
Na+/Ca++
Exchanger
Na+
Ca++

12. THE ISCHEMIC CASCADE

13. LEARNING GOALS Scope of the problem Stress ECG Stress echocardiography
Reconciling the evidence

14. TREADMILL STRESS TEST

15. KEY ACCESSORY

16. EQUIPMENT FOR STRESS TESTING
Treadmill or bicycle or steps
ECG machine
Blood pressure cuff
Computer is a ‘nice to have’
ACLS certification
Defibrillation/intubation cart
Exit strategy
Good help* (it takes two to test)

17. PROTOCOLS

18. TYPICAL BRUCE OR RAMP STRESS
WORK
WORK
TIME
TIME

19. WHY USE A BIKE ERGOMETER?
1. Accurate measurement of POWER. 2. Ramping protocols allow for assessment of physiologic function across all work levels. 3. Independent of patient’s weight. 4. Less danger of fall and injury to patient. 5. Easier to take accurate B/P at high work rates. 6. Patient can stop at anytime. 7. Holding handle bars does not effect test (Holding treadmill handrails can significantly effect results). 8. Fits into smaller space and is portable. 9. Patients with knee or hip problems tend to perform better and report being more comfortable on the bike.

20. WHY USE A BIKE ERGOMETER?
10. Bike ramp protocols are designed to last 6-10 minutes, resulting in less fatigue (yet peak work is maximized).
11. HR, Work, and VO2 (Cardiac Output) are linearly related. Bike ramp protocols produce linear increases in Work, thereby mimicking the expected physiologic response in health and disease.
12. Determination of the Anaerobic Threshold (AT) by the most popular methods (V-slope and VE/VO2 nadir) were developed and proven through the use of bike ramp protocols. To use another method means to lose AT detection accuracy.
13. Bike ramp protocols are used by many of the leading clinical and research cardiopulmonary exercise testing labs (UCLA, Duke, Mayo, Stanford, Bowman-Gray, Johns Hopkins, UAB, Temple to name a few). Recently, treadmills capable of performing ramp protocols have been developed.

21. MY VIEW: TREADMILL IS BEST

22. INDICATIONS TO STRESS TEST
Diagnosis of coronary artery disease
Risk-stratification of coronary artery disease
Risk-stratification in cardiac valve disease
Appraisal of rate response
Appraisal of pressure response to stress
Appraisal of functional capacity

23. Exercise duration/tolerance Reproducibility of symptoms with activity
INFORMATION OBTAINED FROM EXERCISE STRESS BUT NOT AVAILABLE WITH PHARMACOLOGICAL TEST
Exercise duration/tolerance
Reproducibility of symptoms with activity
Heart rate response to exercise
Blood Pressure response
Detection of stress induced arrhythmias
Assess control of angina with medical therapy
Prognosis

24. KEY ASPECTS Exercise duration and work-load (minutes, METs, Watts)
Maximum blood pressure
Maximum heart rate (given that predicted for age)
Rate-pressure product
Baseline ECG
ST-segment changes
T-wave changes
Q waves
Duke treadmill score
Heart rate recovery

25. ABNORMAL RESPONSE TO STRESS TESTING
Heart rate fails to rise above 120 or unable to attain target heart rate of 85% of max
Blood pressure shows a drop in systolic
Patient physically unable to complete test
Marked hypertension, >260/115
Chest Pain and/or unusual shortness of breath

26. NORMAL RESPONSE OF ECG TO STRESS TESTING
ECG Changes
QRS complex decreases in size
J point depresses, resulting in up sloping of ST segment
ST segment returns to baseline by 80 milliseconds
PR segment may down slope – thus baseline is defined as PQ junction
R amplitude may decrease at rates that go above 130
T wave decreases

27. ABNORMAL RESPONSE OF ECG TO STRESS TESTING
ECG Changes
Horizontal or down sloping ST segments
ST segment depressed or elevated
ST segment does not return to baseline by 80 milliseconds
U or T wave inversion
Dysrhythmias – rate dependent blocks above first degree, WPW appears, Atrial fib/flutter, multiform and/or increasing PVC’s, V-tach occurs

28. ECG CHANGES

29. ECG CHANGES

30. RISK

31. CRITERIA DIAGNOSTIC FOR ISCHEMIA
Horizontal or down sloping ST segment with depression of 1 or greater mm.
Horizontal, up or down sloping ST segment with elevation of 1 or greater mm.
Up sloping ST depression greater than 1.5 mm at J+80 msec.

32. CRITERIA DIAGNOSTIC FOR ISCHEMIA
Horizontal or down sloping ST segment with depression of 1 or greater mm.
Horizontal, up or down sloping ST segment with elevation of 1 or greater mm.
Up sloping ST depression greater than 1.5 mm at J+80 msec.

33. CRITERIA SUGGESTIVE FOR ISCHEMIA
Horizontal or down sloping ST segment with depression greater than 0.5mm but <1 mm.
Up sloping ST depression between 0.7 and 1.5mm at J+80 msec.
Chest pain or fall in Blood pressure or persistent HTN in recovery or new S3 or murmur at peak exercise.
(<1 mm)

34. 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)

35. PREDICTED MAXIMUM HEART RATE

36. 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

37. MAJOR DETERMINANTS OF MYOCARDIAL OXYGEN CONSUMPTION
Picano, Circ 1998

38. PROGNOSTIC ROLE OF METs
Myers et al, New Engl J Med 2002

39. PREDICTING CARDIAC DEATH
Marcus et al, Chest 1995

40. DUKE TREADMILL SCORE

41. BAYES THEOREM If P(B) ≠ ), then P(A/B) = “ P(B/A)P(A) “
P(B/A)P(A) + P(B/not A)P (not A)

42. CONTINUOUS OF RISK

43. TYPICAL REPORT
Treadmill stress test stopped at the end of the 3rd standard Bruce stage for fatigue (max BP 200/100 mm Hg, max HR 140 bpm, RPP 28,000).
No symptoms. No arrhythmias. No abnormalities in the baseline ECG. In the 2nd stage development of ST depression, which becomes diagnostic in the 3rd stage (max 1.5 mm in V5 at the peak), with quick recovery after the stress.
Duke treadmill score: 1 (<-11 high risk; >4 low risk).
Heart rate recovery: 10 (valore di riferimento >12).
Positive stress test for myocardial ischemia at mid-to-high work-load.

44. GUIDELINES
Gibbons et al, Circ 2002

45. GUIDELINES: RECOMMENDATIONS
Gibbons et al, Circ 2002

46. GUIDELINES: RECOMMENDATIONS
Gibbons et al, Circ 2002

47. STRESS EKG IS NOT A SLAM DUNK
5/10,000 result in serious cardiovascular event
1/10,000 result in death
Results are based on Bayes Theorem
Requires proper selection, preparation, and execution
Not the GOLD standard

48. LEARNING GOALS Scope of the problem Stress ECG Stress echocardiography
Reconciling the evidence

49. STRESS ECHOCARDIOGRAPHY

50. BASIC PRINCIPLE OF STRESS ECHO

51. BASIC PRINCIPLE OF STRESS ECHO

52. WALL MOTION RESPONSES
Sicari et al, Eur Heart J 2009

53. CARDIAC SEGMENTS

54. WALL SEGMENTS AND CORONARY DISTRIBUTION

55. CURRENT STRESS PROTOCOLS
ECG ECHO NUCLEAR
Exercise: Tread Post-Tread Tread
Bicycle Bicycle
Pharmacologic:
Catecholamines: Dobutamine Dobutamine
Vasodilators: Dipyridamole Dipyridamole Dipyridamole
Adenosine Adenosine
Vasospastic: Ergonovine Ergonovine
Adjuncts: Atropine
Handgrip

56. INDICATIONS TO STRESS ECHOCARDIOGRAPHY
Diagnosis of coronary artery disease
Risk-stratification of coronary artery disease
Risk-stratification in cardiac valve disease
Appraisal of myocardial viability
Patients unable to ambulate

57. PREPARATION Avoid smoking Avoid food/beverages
Take all medications unless instructed otherwise
Wear comfortable clothes and shoes

58. KEY PHARMACOLOGICAL TESTS
Picano, Circ 1998

59. DOBUTAMINE PROTOCOL
Sicari et al, Eur Heart J 2009

60. DIPYRIDAMOLE PROTOCOL
Sicari et al, Eur Heart J 2009

61. FURTHER APPLICATIONS
Sicari et al, Eur Heart J 2009

62. LEARNING GOALS Scope of the problem Stress ECG Stress echocardiography
Reconciling the evidence

63. PATIENTS APPROPRIATE FOR ROUTINE ECG STRESS TEST WITHOUT IMAGING
Patient can exercise for 6 or more minutes
Normal baseline ECG
No history of diabetes
No history of coronary revascularization
No history of myocardial infarction

64. ABSOLUTE CONTRAINDICATIONS
Within 24 hours of troponin positive ACS
Within 7 days for high dose DSE after STEMI
Left ventricular failure with symptoms at rest (in tertiary centres viability may be assessed using low dose dobutamine stress).
Recent history (within the last week) of life threatening arrhythmias.
Severe dynamic or fixed left ventricular outflow tract obstruction although low dose DSE may be useful.
BP >220/120
Recent pulmonary embolism or infarction.
Thrombophlebitis or active deep vein thrombosis.
Known hypokalaemia (particularly for Dobutamine stress)
Active endocarditis, myocarditis, or pericarditis.

65. POSSIBLE CONTRAINDICATIONS TO STRESS TESTING BASED ON RESTING ECG
ST-segment changes 1 mm or greater, either depression or elevation
Ventricular strain patterns or hypertrophy
T-wave inversions
Left bundle branch block
Right bundle branch block, if significant
Prolonged QT interval

66. ABSOLUTE CONTRAINDICATIONS TO DOBUTAMINE STRESS ECHO
Suspected or known severe bronchospasm
2nd or 3rd degree AV block without pacemaker
Sick sinus syndrome without pacemaker
BP <90mmHg systolic
Xanthines taken in the last 12 hours, or dipyridamole use in the last 24 hours

67. FIRST THINGS FIRST: DIAGNOSTIC PERFORMACE OF DIFFERENT TESTS

68. Heijenbrok-Kal et al, Am Heart J 2007
CHOOSING YOUR TEST
Heijenbrok-Kal et al, Am Heart J 2007

69. CHOOSING YOUR TEST
Froelicher et al, Chest 1999

70. CARDIAC STRESS IMAGING
Picano, Am J Med 2003

71. ADVANTAGES OF STRESS ECHOCARDIOGRAPHY COMPARED TO NUCLEAR STRESS TESTING
Higher Specificity
Visualization of cardiac valves
Evaluate for presence of pericardial effusion
Ability to measure RV Systolic Pressure
More accurate assessment of LV ejection fraction
Doppler interrogation to determine Diastolic Function
Lower Cost
Lack of Radiation Exposure

72. TAKE HOME MESSAGES
Stress testing, by either stress ECG, stress nuclear scan, dipyrididamol/dobutamine nuclear scan, stress echocardiography, dipyrididamol/dobutamine echocardiography, is crucial in the diagnostic work-up of patients with suspected coronary heart disease
These tests are also useful in the prognostic work-up of patients with established coronary heart disease
Given financial and logistic constraints, stress ECG should be performed in most suitable subjects as 1st line test, followed/substituted by imaging tests in all the other cases

73. Thank you for your attention For any correspondence: For these and further slides on these topics feel free to visit the metcardio.org website: