Medical assistant's role in cardiovascular examinations and diagnostics

Patients with cardiovascular system concerns are seen in urgent care, primary care, and cardiology departments. Medical assistants working in these departments assist with examinations, diagnostic procedures, and treatments.

Assisting with the examination

The cardiovascular examination begins with the medical assistant measuring the patient’s height and weight, temperature, radial pulses, respirations, and blood pressure in both arms. Most cardiologists also want a complete list of the vitamins as well as the herbal, prescription, and over-the-counter (OTC) medications the patient is taking, including the strength and frequency of use for each.

A large part of the provider’s examination focuses on subjective symptoms. The physical examination covers the chest, heart, and vascular systems. The patient’s general appearance will be observed, as well as the color of the skin, symmetry, temperature of the extremities, and breathing patterns. The veins in the neck may be examined for distension (enlargement). Using a stethoscope, the provider will listen to the lungs, because abnormal sounds may indicate congestion (fluid in the lungs), and the heart. A murmur (fluttering sound) is an abnormal heart sound. The provider may also use a Doppler to check the pulses. A bruit (blowing or swishing sound) can be heard over a carotid artery, aorta, or an organ and is caused by the blood flowing through a narrow artery.

Assisting with diagnostic procedures

The medical assistant can support the provider by doing some diagnostic tests in the exam room. Obtaining the blood pressure in both arms and performing orthostatic vital signs are common procedures. The medical assistant can also perform electrocardiography and Holter monitor testing, which are discussed in another chapter. Besides these procedures, assisting with scheduling and preparing patients for procedures outside the department also fall into the medical assistant’s scope of practice.

The medical assistant may need to screen the patient for specific allergies, medications, and so on prior to scheduling the procedure. For some procedures, a signed consent form is required. The patient should be notified of what will be experienced during the procedure and any follow-up care required after the test.

Angiography

Angiography is used to study blood vessels and detect occlusions, aneurysms, and structural defects. The procedure uses X-rays, computed tomography (CT), or magnetic resonance imaging (MRI) with contrast medium. The contrast medium makes the blood vessel visible on the X-ray images.

For regular angiography, the patient may be NPO (nothing by mouth) at midnight before the procedure. During the procedure, an intravenous (IV) line may be inserted and a sedative given to help relax the patient. The heart and blood pressure may be monitored during the procedure. After the area (e.g., groin) is shaved and cleansed, a small incision is made. A catheter is threaded into the blood vessel (e.g., femoral or carotid arteries) and advanced to the area that will be studied. Radiopaque contrast medium is injected to make the blood vessel appear on the x-ray. The patient may experience a burning or warming sensation in the location where the medium is given. A series of x-rays are taken. Some treatments can be done during the angiography. After the procedure, the patient is monitored as the medication wears off. The incision is monitored for bleeding. The patient needs to drink plenty of fluids to flush the dye from the body.

There are several types of angiographies:

• Arteriography: A type of angiography that involves the study of arteries.
• Cerebral angiography: Used to detect blood clots, aneurysms, and other vascular conditions in the brain.
• Coronary angiography: A series of x-rays are taken of the heart. The catheter can also monitor the blood pressure in the heart. Coronary angiography is part of a group of procedures known as cardiac catheterization.
• Pulmonary angiography: This test is used to evaluate the pulmonary artery for blood circulation conditions (e.g., pulmonary embolism).

A computed tomography angiography (CTA) and magnetic resonance angiography (MRA) differ from a regular angiography. They are noninvasive and do not require recovery time, although no treatments can be done during the procedure. Caffeinated beverages may be restricted 12 hours before the test, and the patient may not eat for 4 hours before the test to prepare. The patient can drive before and after the test. A patient may receive a beta-blocker to slow the heartbeat or nitroglycerin to dilate the coronary arteries, making the images clearer. During the procedure, the contrast medium is given intravenously. Electrodes are placed on the patient’s chest to monitor the heart during the procedure. After the test, the patient can resume normal activities, although it is important to increase the fluids consumed in order to flush the contrast medium from the body.

Cardiac catheterization

Cardiac catheterization is a procedure used to diagnose and treat certain heart diseases. The patient preparation is similar to that for an angiography, although the patient may be restricted from eating and drinking for a longer period of time.

During the cardiac catheterization, a regular coronary angiography is done. The catheter is inserted into an artery in the groin and threaded to the heart. The contrast medium is injected, and narrowed or blocked arteries can be observed. The provider can also measure pressure, blood flow, and oxygen amounts in the chambers and large arteries. Blood samples and biopsies can be collected.

Based on what is found during the catheterization, the provider may also treat the condition. These treatments may include the following:

• Repair of congenital heart defects
• Angioplasty: A treatment to open narrowed blood vessels by expanding a small balloon at the site, which widens the vessel; a stent (small metal coil) may be inserted to help keep the vessel open
• Replacement or repair of a heart valve

Doppler ultrasound

The Doppler ultrasound exam provides information on the blood flow in the arms and legs. This test is used to help diagnose arteriosclerosis, arterial occlusion (from blood clots), peripheral artery disease, aneurysms, arterial stenosis, and venous insufficiency. There is no special preparation for this test. The patient needs to remove clothing on the extremity being tested.

During the test, the sonographer applies gel to the extremity and places a handheld transducer on the patient. The transducer directs ultrasound waves (high-frequency sound waves) over the vein or artery being checked, and the waves bounce off the circulating RBCs. This test helps the provider estimate the blood flow through the vein or artery. A color Doppler uses a computer to change sound waves into different colors. The colors show the speed and direction of the blood flow.

A simple handheld Doppler can often be used in the exam room to check the pulses in the extremities. An absent pulse means there is no blood flow through the artery, which is a medical emergency. With training, a medical assistant can use a handheld Doppler to check the pulses.

Echocardiography

An echocardiogram is a sonographic test that uses sound waves to create pictures of the heart structures. It shows the heart beating and the heart valves and other structures in motion.

Most people have a transthoracic echocardiogram (TTE). There is no special preparation for this test. The patient must remove any clothing and jewelry from the waist up and lie on the exam table in a supine position. A trained echocardiogram sonographer spreads warmed gel over the patient’s chest and then moves a transducer slowly over the chest. The transducer releases high-frequency sound waves and picks up the waves. The waves are transmitted as electrical impulses that are converted by the echocardiography machine into moving pictures. During the process, the sonographer can take still pictures of the heart’s structures.

A transesophageal echocardiogram (TEE) is done less often, and it requires the patient to not eat or drink for several hours before the test. The patient may be given a sedative for the procedure. The patient’s throat is numbed before the provider guides a probe (a long flexible tube) with a small ultrasound transducer down the throat and to the stomach. The TEE can get clearer echocardiographic images of the heart than the TTE can.

Electrocardiography and related procedures

An electrocardiography (ECG, EKG) provides a recording of the electrical impulses of the heart as wave deflections. An electrocardiograph creates the record or recording, which is called the electrocardiogram. The patient is asked to remove jewelry and clothing above the waist to prepare for the test. Electrodes are applied to the skin, and lead wires from the electrocardiograph are attached to the electrodes.

ECGs are taken with other tests:

• Exercise stress test (EST) or exercise electrocardiogram: Tests the electrical activity of the heart during exercise on a treadmill. Patient coaching prior to the test includes having the patient dress for exercise. Food, drink, and nicotine are restricted 3 or more hours before the test, and no caffeine is allowed for 24 hours prior to the test. A consent form needs to be completed. Patients should let the provider know if any chest discomfort or pain, dizziness, palpitations, or shortness of breath occur during the test.
• Nuclear stress test: A nuclear imaging test that shows blood flow into the heart at rest and with activity. Many names for the test exist, which reflect the intravenous (IV) substance given (e.g., thallium or sestamibi stress test). Patient coaching prior to the procedure usually includes the following:
• Caffeine is restricted 24 hours before the test.
• The patient should dress for exercise if a treadmill will be used.
• A camera takes pictures of the heart while the patient is at rest and when the heart rate is increased either with medication or activity.
• Holter monitoring: A portable electrocardiograph is worn to record the reaction of the heart to daily activities for a few days. Electrodes are applied to the chest. The patient receives information on how to complete the journal and use the monitor for the study.
• Event recording: A portable electrocardiograph is worn for several weeks. The patient presses a button on the recorder when symptoms occur.
• Tilt table test: The patient is placed on a tilt table and secured with straps. As the table is tilted in various positions, the patient’s blood pressure and ECG are monitored. This test is used to diagnose orthostatic hypotension.