Myocardial Infarction Stress Testing

1. Myocardial Infarction
Alpesh C. Jadhav
B.Sc.(Hons) Sports & Exercise Sciences

2. Myocardial Infarction
(Heart Attack)
A Medical Condition caused by Reduced Blood
Flow in a Coronary Artery due to
Atherosclerosis & blockage of an artery by an
Thrombus or Embolus.
The Irreversible Damage of Myocardial Tissue
caused by Prolonged Ischemia & Hypoxia.

3.  CAD (CORONARY ATHEROSCLEROSIS DISEASE)
 Accumulation of Lipids, Macrophages, Blood-
clotting Elements, Calcium, & Fibrous Connective
Tissues within inner linings of Coronary Arteries.
 Atherosclerotic Changes in Coronary Artery,
forming Plaque & lesions,
Causing impairment Or Obstruction in
Normal Blood Flow.
 Myocardial Ischemia (ST-Depression)
 Myocardial Infarction (ST-Elevation)

5. EFFECTS ON EXERCISE RESPONSE
 AMI (Acute Myocardial Infarction) alters Cardiorespiratory &
Hemodynamic Responses to Both Sub-Maximal & Maximal
Exercise.
 Reduced “O2 Transport Capacity” Due to “Less Cardiac Output”
 In Some Individuals, due to Residual Ischemia or Necrosis :
Decreased Contractile Force of Left Ventricle
Manifestations: Blunt or Decreased SBP
 In other Cases,
Cardiac Output may be Limited by “Restrictions in Rise of HR”
due to “Intrinsic Disease of SA or AV Node”, OR
by Anginal Symptoms Appearance
with or without Ischemic ST-Segment Depression.

6. Exercise-induced Ventricular Arrhythmias
Occurs more Commonly in Individuals with H/O
Previous MI. (Potential Life-Threatening Sign)
For Clients, with H/o Previous MI
often take Medications
to Decrease Heart Rate and Blood Pressure.
Before Client Undergoes Exercise Testing,
Type & Dose of Medications should be Noted.

7. Recommendations for
Exercise Testing
 “Low-Level Exercise Testing” (≤5 METS) is Used for individuals
recovering from MI to Assess Functional Status, as well as to Provide
Diagnostic, Prognostic, and Therapeutic Guidance.
 Exercise Testing serves to promote Client Confidence, Providing
Reassurance that Routine Activities can be undertaken Safely.
 Abnormal Findings (Eg. Angina, Ischemic ST-Segment Depression)
suggests that Additional areas of Myocardium are served by Stenosed
Coronary Vessels and remain in Jeopardy (Danger of Harm/Failure).
 The Test Protocol for Peak or Symptom-Limited Testing
should focus on individuals ability to perform Lower-Extremity
Exercises

8.  People Unable to Perform Treadmill or Cycle Ergometer
Exercises
may be alternatively evaluated with Arm-Cranker Ergometry or
Pharmacologic Stress Testing at Rest.
 The Exercises Test should Begin at an Intensity level
“considerably below” The Anticipated Peak or Symptom-
Limited Capacity
and increase gradually in 2-3 min Stages, with Hemodynamic
Measures made at Each Progressive Stage.
 If Possible, Exercise Capacity should be measured using GAS
EXCHANGE TECHNIQUES rather than predicting from Work
Rate, Which tends to Overestimate Aerobic Fitness
 “Contraindications to testing” and “indications for
terminating Exercise” should be Closely Observed.

9. The Primary Objectives of Exercise Testing for Individuals
Recovering from or with H/O MI are To Evaluate and
accurately the following functions:
i. Chronotropic Capacity & Heart Rate Recovery
ii. “Myocardial Exercise Capacity”, Estimated by Peak Rate-
Pressure Product (HR*SBP)
iii. Exertional Symptoms (Eg. Increasing Chest Pain or Light
Headedness)
iv. Associated Changes in Electrical Functions of Heart (Eg. Arrhythmias,
ST-T wave changes)
The Data Collected during an Exercise Test are critical to
categorize Risk Status (Eg. Low, Moderate, High) &
Establish a Safe and Effective Metabolic Load for
“Aerobic Exercise Training”.

10.  Indicators of an Adverse Prognosis in the Post-MI Client
include the Following:
I. Ischemic ST-Segment Depression at a Low Level of Exercise
II. Functional Capacity ≤4 METS
III. Low Peak Rate-Pressure Product (HR*SBP)
IV. Hypotensive BP response Exercise.
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 Exercise Testing for Individuals on “Long-Acting” Beta-
Blockers should be conducted at Same time of the Day the
Subject will be Exercising,
 Because of The Significant Reduction in Exercise Heart Rate
may dissipate over time.

11. STRESS TESTING
 Tests used to measure Heart’s Ability to respond to an
External Stress in a Controlled Clinical Environment
 TYPES OF STRESS TESTING
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EXERCISE
 Treadmill
 Bicycle
PHARMACOLOGIC
 Adenosine
 Dipyridamole
 Dobutamine
 Isoproterenol
OTHER
 Pacing

12. METHODS OF DETECTING ISCHEMIA
DURING STRESS TESTING
Electrocardiography
Echocardiography
Myocardial perfusion imaging
Positron emission tomography
Magnetic resonance imaging

13. The main types of exercise are Isotonic exercise,
Isometric exercise, and resistive (combined isometric
and isotonic) exercise.
Isometric:
Holding a static pushup position;
Holding a dumbbell in one hand
Isotonic:
Weight lifting
Swimming
Cycling

14. General concerns prior to performing an exercise
test include :
 Safety Precautions and Equipment's needs.
 Patient preparation
 Choosing a test type
 Choosing a test protocol
 Patient monitoring
 Reasons to terminate a test
 Post test monitoring

15. VARIOUS PROTOCOLS
Treadmill protocols:
Bruce
Cornell
Balke ware
Acip
mAcip
Naughton
Weber
Bicycle ergometer

16. MEASUREMENTS
ECG
Exercise capacity (METS – metabolic equivalent)
Symptoms
Blood pressure
Heart rate response & recovery

21. Bibliography

22. Thank You