1. Chapter 25 Medical Testing
Health Care Science Technology
Copyright © The McGraw-Hill Companies, Inc.

2. Objectives
Describe the role and responsibilities of an electrocardiography technician.
Explain the role and responsibilities of a cardiovascular technologist.
Identify two or more cardiovascular diagnostic tests.
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3. Objectives (cont.)
Contrast the roles and responsibilities of the electroencephalography (EEG) technologist and the electroneurodiagnostic technologist.
Explain the purpose of an electroencephalogram.
Successfully complete 1 medical testing procedure.
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4. Careers in Medical Testing 25-1
Electrocardiography Technician
Cardiovascular Technologist
EEG and END Technologists
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5. Careers in Medical Testing
Career opportunities are excellent, including the four most common occupations:
Electrocardiography (ECG) technician.
Cardiovascular technologist.
Electroencephalography (EEG) technologist.
Electroneurodiagnostic (END) technologist.
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6. Electrocardiography Technician
Uses an electrocardiograph to record the electrical activity of the heart as a tracing.
Electrocardiograms help diagnose and evaluate cardiovascular disease.
Determines if the tracing is accurate and prepares a report for the physician.
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7. Electrocardiography Technician (cont.)
Job Responsibilities
Perform a safe and accurate ECG.
ECG monitor technicians evaluate the electrical tracings on a monitor.
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8. Electrocardiography Technician (cont.)
Exercise Electrocardiography
Also known as stress test or treadmill test.
Job responsibilities
Provide client safety.
Provide instructions to client.
Monitor the client by taking blood pressure.
Observe for pain, discomfort, fatigue, or difficulty breathing.
Apply and remove electrodes.
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9. Electrocardiography Technician (cont.)
Ambulatory Monitoring
Tracings are recorded on a client who is ambulatory. Often a Holter monitor is used.
Job responsibilities
Apply and remove the ambulatory monitor.
Provide client education.
Ensure results are placed in the client’s chart.
Maintain the equipment.
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10. Cardiovascular Technologist
May need up to 4 years of education and training.
Works directly with cardiologists in clinics, hospitals, physician’s offices, medical centers, and mobile diagnostic units.
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11. Cardiovascular Technologist (cont.)
Job Responsibilities
May assist physicians with heart surgery, implantation of pacemakers, and invasive tests such as angioplasty and cardiac catheterization.
Some specialize in performing ultrasound on the heart and blood vessels in the test called an echocardiogram.
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12. Cardiovascular Technologist (cont.)
Cardiovascular Testing
A cardiovascular technician needs:
A thorough understanding of the anatomy and physiology of the cardiovascular system.
An ability to work with computers and other technical equipment.
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13. Cardiovascular Technologist (cont.)
Cardiovascular Testing (cont.)
Cardiac Catheterization
This test looks at the structures of the heart.
A small tube is threaded through the client’s blood vessels to the heart, where pressure is measured and dye is injected.
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14. Cardiovascular Technologist (cont.)
Cardiovascular Testing (cont.)
Balloon angioplasty
A catheter with a balloon on its end is inserted into a blood vessel; then the balloon is inflated to expand the blood vessel.
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15. Cardiovascular Technologist (cont.)
Job Responsibilities
Review and record the client’s history.
Perform diagnostic tests.
Monitor heart rate, blood pressure, and ECG.
Inform the physician if something appears wrong.
Use discretion and judgment when performing duties.
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16. EEG and END Technologists
The title END is more commonly used, as it most accurately describes the occupation.
Other important terms are:
Electroencephalography – recording the electrical activity in the brain.
Electroneurodiagnostic – evaluating the electrical activity of the nervous system.
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17. EEG and END Technologists (cont.)
Job Responsibilities
Perform tests that evaluate the spinal cord, the nervous system, and sleep.
Usually employed in:
Acute care hospitals.
Neurologists’ offices.
Some ambulatory care facilities.
Newborn nurseries.
Sleep study laboratories.
Operating rooms.
Epilepsy research centers.
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18. EEG and END Technologists (cont.)
The electroencephalogram
Records the electrical impulses of the brain, producing a record called the electroencephalogram.
The END technologist obtains the client’s medical history, then applies electrodes to the head.
The END technologist corrects errors on the tracing that are caused by interference during the EEG.
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19. Section 25-1 Apply Your Knowledge
List some invasive procedures the cardiovascular technologist might help perform.
Answer:
Angioplasty, cardiac catheterization, heart surgery, and implantation of pacemakers.
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20. Medical Testing Procedures 25-2
Recording an Electrocardiogram
Anatomy and Physiology of the Heart
Background for Recording an ECG
Twelve-Lead ECG
ECG Machines
ECG Machine Controls
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21. Recording an Electrocardiogram
An electrocardiogram (ECG tracing):
Determines how well the heart is pumping and contracting.
Checks for problems with the flow of electricity through the heart.
Diagnoses changes in the heart rhythm.
Checks for abnormal heart changes before surgery.
Assists in evaluating a person’s health after age 40.
Monitors or evaluates individuals with heart conditions.
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22. Anatomy and Physiology of the Heart
Sinoatrial (SA) node.
Atrioventricular (AV) node.
Bundle of His (AV bundle).
Bundle branches.
Purkinje fibers (network).
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23. Background for Recording an ECG
The technician must understand the heart’s electrical conduction system.
Each contraction of the heart muscle is controlled by electrical impulses.
The pattern of current is recorded by the ECG machine.
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24. Background for Recording an ECG (cont.)
The ECG Waveform
The deflections on a tracing rise above or fall below a straight line.
This line is known as an isoelectric line, or baseline.
Positive deflections go up, negative ones go down.
Each wave represents specific activity in the heart.
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25. Twelve-Lead ECG
Gives a recording of the electrical activity within the heart.
Attaching the leads and electrodes:
Six leads are attached to the chest electrodes.
Four leads are attached to electrodes on the arms and legs.
The 10 lead wires produce 12 different lead circuits.
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26. Twelve-Lead ECG (cont.)
Working with Electrodes
Reusable electrodes – plates and bulbs.
Disposable electrodes – used to reduce possible contamination.
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27. Twelve-Lead ECG (cont.)
Proper Handling and Storage
Keep unused electrodes in a sealed plastic bag.
Check the expiration date.
Ensure the gel has not dried.
Always check electrodes before you use them.
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28. ECG Machines Single-Channel ECG – monitors 12 leads individually.
Multichannel ECG – produces all 12 leads by recording 3 leads at once.
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29. ECG Machines (cont.) Other Types of ECG Machines
Some perform functions such as computerized measurement and analysis, storage, and communication.
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30. ECG Machine Controls Speed. Gain. Artifact filter.
Computerized controls.
Standardizing with the stylus.
Lead selector.
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31. Section 25-2 Apply Your Knowledge
How many wires are used in a 12-lead ECG?
Answer: 10.
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32. Procedures in Student Text
25A Recording an Electrocardiogram
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33. Chapter 25 Credits Slide 6 Geoff Butler Slide 7 Geoff Butler
Slide 10 Chip Henderson/Index Stock Imagery
Slide 26 Geoff Butler
Slide 28 Geoff Butler
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