1. Stress Testing : Which Test to Choose?
Gary J. Balady, MD
Professor of Medicine
Boston University School of Medicine

2. Stress Testing at Boston Medical Center
Exercise ECG ( treadmill test)
Exercise – Echo
Exercise – Nuclear
Cardiopulmonary ( Metabolic )
Dobutamine –Echo
Pharmacologic (regadenoson) nuclear
SPECT
PET
SCM Order Set: stress test selector

3. supply
demand

5. supply
demand
coronary arteries
atherosclerosis
coronary vasospasm
hypoxemia
anemia
hypotension
coronary anomalies
coronary vasculitis
factors
HR x BP
contractility
wall stress

6. Supply Degree of obstruction Length of lesion
Dynamic properties of lesion
Dynamic properties of
distal vascular bed
thickness of myocardium

7. Supply
Collateral flow

8. supply
demand
factors
HR x BP
contractility

9. History Chest discomfort Age/Gender/Risk Factors Classes of Angina
Types of angina
Quality of discomfort/location
Provocative factors
Relief
Age/Gender/Risk Factors
Classes of Angina

10. weight/body habitus vascular bruits heart size skin eye grounds
Physical Examination
hypertension
weight/body habitus
vascular bruits
heart size
skin
eye grounds

11. Resting Electrocardiogram

15. Exercise Testing Protocols

16. Work = force x distance Workrate = work/time VO2 is directly related to workrate
Treadmill
Force = body weight
Distance/time=
Treadmill speed
Estimated VO2 (ml/kg/min)
ACSM regression equations
METs
Stationary Cycle
Force = resistance against the flywheel
Distance/time=
Cycling speed
Estimated VO2 (ml/min)
ACSM regression equations
Need body weight to calculate METs

17. Stepped
METs
Ramp
METs
Time 
10 min

18. Bruce Protocol for Treadmill Testing
STAGE
TIME
SPEED (mph)
GRADE (%)
METS
REST
00.00
0.0
1.0 1
03.00
1.7
10.0
4.6 2
2.5
12.0
7.0 3
3.4
14.0
10.1 4
4.2
16.0
12.9 5
5.0
18.0
15.1 6
5.5
20.0
16.9 7
6.8
22.0
19.2

19. Boston Medical Center Ramp Protocols
Stage*
Very Low Ramp
Low Ramp
Moderate Ramp
High Ramp
Athlete’s Ramp
mph
% grade
METs 1
1.0
0.0
1.8
1.5
2.5
2.1
3.0
3.5
2.4 2
1.1
0.2
1.9
0.5
1.6
2.0
2.7
2.2
4.0
3.9 3
1.2
0.4
1.7
2.9
2.3
4.5
4.2
3.2 4
1.3
0.6
3.1
5.5
4.6
3.6 5
1.4
0.8
3.4
6.0
5.0
3.3
4.1 6
2.6
7.0 7
7.5
5.8
5.2 8
2.8
8.5
6.4
6.1 9
9.0
6.8
7.3 10
4.8
10.0
7.4
8.4 11
6.5
5.1
10.5
7.8
9.5 12
11.5
10.6 13
12.0
8.9
5.4 14
8.0
6.2
13.0
9.7
5.7
12.2 15
3.8
6.6
13.5
10.1 16
14.5
10.9
6.3
13.8 17
3.7
15.0
11.4
14.7 18
4.3
16.0
6.9
15.5 19
8.3
16.5
12.6
7.2
16.4 20
4.7
11.0
8.7
17.5
13.3
17.3

20. Duke Activity Status Index

21. Diagnostic level of stress: 85% maximum predicted HR
where MPHR = (220-age)

22. Normal Response
Ischemic
Response

24. Sensitivity/Specificity/Predictive Value high prevalence population63 3 95 27 7 21 90 10
exercise ecg test: 70% sensitive/ 70% specific

25. Sensitivity/Specificity/Predictive Value low prevalence population7 27 21 3 63 95 10 90
exercise ecg test: 70% sensitive/ 70% specific

27. Duke Prognostic Scoring Systemx x * x x

28. Heart Rate Recovery 28

29. Heart Rate Recovery: Risk of mortality at 6 years
Cole, et al. NEJM 1999: 341:1351 29

30. Cleveland Clinic ETT Score
Lauer, et al. Ann Int Med 147: ; 2007

31. Hypertension During Exercise: BPs > 180 at 7 METs
The risk is not immediate, but is evident in the near term – the 5-10 year period which is a focus of most preventive strategies and pharmacotherapies, and continues to increase dramatically in the long term – i.e lifetime risk – the focus of public health groups like the American Heart Association.
Circulation 2010: 121: 2109

32. Oxygen Uptake - Workrate relationship
No handrail
Handrail
VO2  ?
Workrate 

33. CPX System Oxygen sensor Carbon dioxide sensor
Volume measures/flow meters
Breath by breath measures
BTPS
Expired air
Oxygen uptake
Carbon Dioxide production
Ventilation

34. Indications for CPX Accurate assessment of exercise capacity Diagnosis
Clinical
Research
Diagnosis
Dyspnea on exertion
Prognosis
Heart failure
Congenital Heart Disease
Disability assessment
Treatment
Pacemaker settings

35. Exercise Testing additional indications
Adequacy of therapy
medical
revascularization ( imaging tests)
Activity counseling
MET Chart
Exercise prescription
Rhythm assessment
Valvular Heart Disease
Aortic stenosis
Mitral stenosis
Mitral regurgitation
Hypertrophic obstructive cardiomyopathy

36. Exercise Prescription Patients with CHD
Intensity
Exercise Test
calculate heart rate reserve (HRR)
peak HR minus resting HR
moderate intensity:
50% HRR plus resting HR to
70% HRR plus resting HR
keep peak peak HR 10 beats < HR at ischemia
Risk Stratify using AHA criteria

37. Stress Imaging Tests Abnormal resting ECG ST segments
Left bundle branch block
LVH with strain
Need for increased
diagnostic accuracy
sensitivity 85-90%
specificity 85-90%
localize ischemia to
specific coronary vascular territory

39. Contrast Echo

40. Stress Echocardiogram: Apical septal wall ischemia

41. Stress Nuclear Testing tomographic imaging planes
Short Axis
base to apex
Vertical Long Axis
septal to lateral
Horizontal Long Axis
anterior to inferior

42. normal nuclear perfusion scan
stress
rest
stress
rest
stress
rest

43. lateral ischemia on nuclear perfusion scan
stress
rest
stress
rest
stress
rest

44. Pharmacological Stress Tests
dobutamine echo
Dobutamine
beta agonist
increases myocardial oxygen demand
increases HR, BP, contractility

45. Pharmacological Stress Tests
nuclear perfusion scan
Adenosine or Dipyridimole
direct coronary vasodilator
causes shifts in flow leading to
relative reduction in flow distal to coronary stenosis
minimal change in HR, BP, and contractility

46. Myocardial Perfusion Imaging: Pharmacologic Positron Emission Tomography (PET) vs. Single Photon Emission Computed Tomography (SPECT)
PET
Energy: 511 KeV
Resolution: 1.5 cm
Protocol: 45 min
Stress EF
Myocardial flow quantification
More expensive than SPECT
SPECT
Energy: KeV
Resolution: 2.0 cm
Protocol: 2-3 h ( or 2 d)
Post-Stress EF
Courtesy of Edward Miller, MD, PhD

47. www.americanheart.org Scientific publications For more information
Statements and guidelines
Exercise standards -2013 47

48. Elective in Stress Testing
Second and third year residents
3 weeks – preferably continuous
Fellow surrogate
Certification in Exercise-ECG Testing
Supervision and interpretation
Exposure to stress echo and stress nuclear

50. Approximate METs during Stationary Cycle Testing
Body weight
Exercise rate (kg · m · min-1 and watts) kg Lb
Kpms 300
Watts 50
450 75
600
100
750
125
900
150
1050
175
1200
200
110
5.1
6.9
8.6
10.3
12.0
13.7
15.4 60
132
4.3
5.7
7.1
10.0
11.4
12.9 70
154
3.7
4.9
6.1
7.3
9.8
11.0 80
176
3.2
5.4
6.4
7.5
9.6 90
198
2.9
3.8
4.8
6.7
7.6
220
2.6
3.4
6.0
7.7

51. Myocardial Contractility

52. Myocardial Wall Stress
P x R/ Th Th R P