Cardiovascular technologists and technicians assist physicians in diagnosing and treating cardiac (heart) and peripheral vascular (blood vessel) ailments. Cardiovascular technologists may specialize in three areas of practiceóinvasive cardiology, echocardiography, and vascular technology. Cardiovascular technicians who specialize in electrocardiograms (EKGs), stress testing, and Holter monitors are known as cardiographic, or EKG technicians.
Cardiovascular technologists specializing in invasive procedures are called cardiology technologists. They assist physicians with cardiac catheterization procedures in which a small tube, or catheter, is wound through a patientís blood vessel from a spot on the patientís leg into the heart. The procedure can determine whether a blockage exists in the blood vessels that supply the heart muscle. The procedure also can help to diagnose other problems. Part of the procedure may involve balloon angioplasty, which can be used to treat blockages of blood vessels or heart valves without the need for heart surgery. Cardiology technologists assist physicians as they insert a catheter with a balloon on the end to the point of the obstruction.
Technologists prepare patients for cardiac catheterization and balloon angioplasty by first positioning them on an examining table and then shaving, cleaning, and administering anesthesia to the top of their leg near the groin. During the procedures, they monitor patientsí blood pressure and heart rate with EKG equipment and notify the physician if something appears to be wrong. Technologists also may prepare and monitor patients during open-heart surgery and the implantation of pacemakers.
Cardiovascular technologists who specialize in echocardiography or vascular technology often run noninvasive tests using ultrasound instrumentation, such as Doppler ultrasound. Tests are called ďnoninvasiveĒ if they do not require the insertion of probes or other instruments into the patientís body. The ultrasound instrumentation transmits high-frequency sound waves into areas of the patientís body and then processes reflected echoes of the sound waves to form an image. Technologists view the ultrasound image on a screen, and may record the image on videotape or photograph it for interpretation and diagnosis by a physician. As the instrument scans the image, technologists check the image on the screen for subtle differences between healthy and diseased areas, decide which images to include in the report to the physician, and judge if the images are satisfactory for diagnostic purposes. They also explain the procedure to patients, record any additional medical history the patient relates, select appropriate equipment settings, and change the patientís position as necessary. (See the statement on diagnostic medical sonographers
elsewhere in the Handbook to learn more about other sonographers.)
Those who assist physicians in the diagnosis of disorders affecting the circulation are known as vascular technologists or vascular sonographers. They perform a medical history and evaluate pulses by listening to the sounds of the arteries for abnormalities. Then, they perform a noninvasive procedure using ultrasound instrumentation to record vascular information, such as vascular blood flow, blood pressure, limb volume changes, oxygen saturation, cerebral circulation, peripheral circulation, and abdominal circulation. Many of these tests are performed during or immediately after surgery.
Technologists who use ultrasound to examine the heart chambers, valves, and vessels are referred to as cardiac sonographers, or echocardiographers. They use ultrasound instrumentation to create images called echocardiograms. An echocardiogram may be performed while the patient is either resting or physically active. Technologists may administer medication to physically active patients to assess their heart function. Cardiac sonographers may also assist physicians who perform transesophageal echocardiography, which involves placing a tube in the patientís esophagus to obtain ultrasound images.
Cardiovascular technicians who obtain EKGs are known as electrocardiograph (or EKG) technicians. To take a basic EKG, which traces electrical impulses transmitted by the heart, technicians attach electrodes to the patientís chest, arms, and legs, and then manipulate switches on an EKG machine to obtain a reading. A printout is made for interpretation by the physician. This test is done before most kinds of surgery or as part of a routine physical examination, especially for persons who have reached middle age or who have a history of cardiovascular problems.
EKG technicians with advanced training perform Holter monitor and stress testing. For Holter monitoring, technicians place electrodes on the patientís chest and attach a portable EKG monitor to the patientís belt. Following 24 or more hours of normal activity by the patient, the technician removes a tape from the monitor and places it in a scanner. After checking the quality of the recorded impulses on an electronic screen, the technician usually prints the information from the tape so that a physician can interpret it later. Physicians use the output from the scanner to diagnose heart ailments, such as heart rhythm abnormalities or problems with pacemakers.
For a treadmill stress test, EKG technicians document the patientís medical history, explain the procedure, connect the patient to an EKG monitor, and obtain a baseline reading and resting blood pressure. Next, they monitor the heartís performance while the patient is walking on a treadmill, gradually increasing the treadmillís speed to observe the effect of increased exertion. Like vascular technologists and cardiac sonographers, cardiographic technicians who perform EKG, Holter monitor, and stress tests are known as ďnoninvasiveĒ technicians.
Some cardiovascular technologists and technicians schedule appointments, type doctorsí interpretations, maintain patient files, and care for equipment.