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

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. Chapter 25

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. Chapter 25

Careers in Medical Testing 25-1 Electrocardiography Technician Cardiovascular Technologist EEG and END Technologists Chapter 25

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. Chapter 25

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. Chapter 25

Electrocardiography Technician (cont.) Job Responsibilities Perform a safe and accurate ECG. ECG monitor technicians evaluate the electrical tracings on a monitor. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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. Chapter 25

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 Chapter 25

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. Chapter 25

Anatomy and Physiology of the Heart Sinoatrial (SA) node. Atrioventricular (AV) node. Bundle of His (AV bundle). Bundle branches. Purkinje fibers (network). Chapter 25

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. Chapter 25

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. Chapter 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. Chapter 25

Twelve-Lead ECG (cont.) Working with Electrodes Reusable electrodes – plates and bulbs. Disposable electrodes – used to reduce possible contamination. Chapter 25

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. Chapter 25

ECG Machines Single-Channel ECG – monitors 12 leads individually. Multichannel ECG – produces all 12 leads by recording 3 leads at once. Chapter 25

ECG Machines (cont.) Other Types of ECG Machines Some perform functions such as computerized measurement and analysis, storage, and communication. Chapter 25

ECG Machine Controls Speed. Gain. Artifact filter. Computerized controls. Standardizing with the stylus. Lead selector. Chapter 25

Section 25-2 Apply Your Knowledge How many wires are used in a 12-lead ECG? Answer: 10. Chapter 25

Procedures in Student Text 25A Recording an Electrocardiogram Chapter 25

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 Chapter 25