Echocardiogram, also called echocardiography or heart ultrasound, is a noninvasive, painless test that uses high-frequency sound waves to show the shape, size, and movement of the heart. It evaluates patients with chest pain, enlarged cardiac silhouettes on X-ray, ECG changes unrelated to coronary artery disease (CAD), and abnormal heart sounds on auscultation.

A transducer directs ultrahigh-frequency sound waves toward the cardiac structures, which reflect them back. The echoes are converted to images on a monitor and recorded on a strip chart or videotape. Findings are correlated with clinical history, physical exam, and other tests.

The two most common techniques are M-mode (motion mode), for recording the motion and dimensions of intracardiac structures, and two-dimensional (cross-sectional), for recording lateral motion and the spatial relationship between structures.

Types

Transthoracic echocardiogram (TTE). The most common type, noninvasive. A transducer on the chest transmits ultrasound into the thorax. The waves bounce off cardiac structures, creating images and sounds on a monitor.
Transesophageal echocardiogram (TOE). An endoscope guides the transducer into the esophagus for a more detailed image than TTE.
Stress echocardiogram. Done while the patient walks a treadmill or rides a stationary bicycle, measuring heart function at rest and during exercise.
Dobutamine stress echocardiogram. For patients who cannot exercise, dobutamine is given IV to stimulate the heart like exercise. It evaluates coronary artery disease and the effectiveness of a cardiac regimen.
Doppler echocardiogram. Measures and assesses blood flow through the heart and vessels.

Indication

Detect and evaluate valvular abnormalities
Detect atrial tumors
Measure the size of the heart chambers
Evaluate chambers and valves in congenital heart disorders
Diagnose hypertrophic and related cardiomyopathies
Evaluate cardiac function or wall motion after myocardial infarction
Detect pericardial effusion and mural thrombi

Procedure

Position supine. Conductive gel is applied to the third or fourth intercostal space to the left of the sternum, and the transducer is placed over it.
Place the transducer. It directs ultrahigh-frequency sound waves toward cardiac structures, picks up the echoes, converts them to electrical impulses, and relays them to the machine for display.
Use motion mode. In M-mode, a single pencil-like beam strikes the heart and produces a vertical view, useful for recording the motion and dimensions of intracardiac structures.
Reposition. In two-dimensional echocardiography, a cross-sectional view records lateral motion and spatial relationships. For a left lateral view, the patient lies on the left side.
Angle the transducer. It is systematically angled to direct waves at specific parts of the heart.
Record findings. The screen is observed and significant findings are recorded on a strip chart or video recorder.
Doppler echocardiography. Color flow shows red blood cell movement through the heart valves, and the sound of blood flow helps assess heart sounds and murmurs against cardiac hemodynamics.

Interfering Factors

Unnecessary patient movement during the procedure
Incorrect transducer placement over the test area
Metallic objects in the field, which hinder visualization and blur images
Dehydration, which blurs the boundaries between organs and tissue
Severe chronic obstructive pulmonary disease, where air between the heart and chest wall conducts ultrasound poorly
Obesity, where the enlarged space between the heart and transducer reduces accuracy

Nursing Responsibilities

Before the procedure

Explain the procedure. Echocardiography evaluates the size, shape, and motion of cardiac structures. Tell who performs it, where, and that it is safe, painless, and noninvasive.
No special prep. No food or fluid restriction is needed.
Have the patient void. Empty the bladder and change into a gown.
Encourage cooperation. Stay still, since movement distorts results. The patient may be asked to breathe in or out or briefly hold the breath.
Explain the darkened room. Dimming aids monitor visualization, and ECG and phonocardiography may run at the same time to time cardiac events.
Explain a possible vasodilator (amyl nitrate). The patient may inhale a gas with a slightly sweet odor while changes in heart function are recorded.

During the procedure

Apply conductive gel. A quarter-sized transducer is placed over the gel on the chest. Warn of minor discomfort from the pressure needed to keep contact.
Position on the left side. The transducer is angled to view different areas of the heart, and the patient may be repositioned on the left side.

After the procedure

Remove the conductive gel. Clean it off the chest wall when the procedure is done.
Explain the report. The physician interprets the study and discusses findings with the patient.
Resume diet and activity. No special care follows the test.

Normal Results

Mitral valve: Anterior and posterior leaflets separate in early diastole and reach maximum excursion rapidly, then move toward each other during ventricular diastole. After atrial contraction, the leaflets come together and stay together during ventricular systole.
Aortic valve: Cusps move anteriorly during systole and posteriorly during diastole.
Tricuspid valve: Motion resembles the mitral valve.
Pulmonic valve: Movement is posterior during atrial systole and ventricular ejection, with the cusp moving anteriorly and reaching its most anterior position during diastole.
Ventricular cavities: The left ventricular cavity is normally an echo-free space between the interventricular septum and the posterior left ventricular wall.
Right ventricular cavity: Normally an echo-free space between the anterior chest wall and the interventricular septum.

Abnormal Results

Mitral stenosis: The valve narrows abnormally from leaflet thickening and disordered motion. During diastole, both leaflets move anteriorly instead of posteriorly.
Mitral valve prolapse: One or both leaflets balloon into the left atrium during systole.
Aortic insufficiency: Aortic valve leaflet flutters during diastole.
Aortic stenosis: The valve thickens and generates more echoes.
Bacterial endocarditis: Disrupted valve motion and fuzzy echoes on or near the valve.
Large chamber size: May indicate cardiomyopathy, valvular disorders, or heart failure. Small chamber size may indicate restrictive pericarditis.
Hypertrophic cardiomyopathy: Systolic anterior motion of the mitral valve and asymmetrical septal hypertrophy.
Myocardial ischemia or infarction: Absent or paradoxical motion in ventricular walls.
Pericardial effusion: Fluid in the pericardial space creates an abnormal echo-free space.
Large effusions: Excess fluid pressure restricts pericardial motion.

Frequently Asked Questions

Does the patient need to fast before an echocardiogram? Not for a standard transthoracic echocardiogram (TTE), which needs no food or fluid restriction. A transesophageal echocardiogram (TEE) does require NPO status, usually several hours, because the probe passes down the throat under sedation.

Is an echocardiogram the same as an ECG? No. An echocardiogram uses ultrasound to image the structure and motion of the heart, while an ECG records the heart's electrical activity. They answer different questions and are often ordered together.

Is an echocardiogram safe and painful? A transthoracic echo is safe, painless, and noninvasive, using sound waves rather than radiation. The patient may feel mild pressure from the transducer on the chest.

What is a stress echocardiogram? An echo done before and after exercise on a treadmill or bicycle, or after IV dobutamine when the patient cannot exercise, to compare heart function at rest and under stress and evaluate for coronary artery disease.

What can an echocardiogram detect? Valve disorders, chamber enlargement, congenital defects, cardiomyopathy, wall-motion changes after a heart attack, pericardial effusion, and mural thrombi.

Why is the patient positioned on the left side? Lying on the left side moves the heart closer to the chest wall, which improves the transducer's view of cardiac structures.

Echocardiogram - Nursing Responsibilities