Echocardiography (echo) can be used to evaluate your cardiac performance, the function of your heart valves, the thickness and motion of your heart walls, and the size of your heart chambers. An echo can help diagnose many heart conditions. Cardiac performance An echocardiogram can show how well your heart pumps blood (cardiac performance). To evaluate your cardiac performance, your doctor will mainly be interested in: • Your left ventricle, which pumps oxygen-rich blood to your entire body.
Many problems, including a faulty heart valve or coronary artery disease, can impair your left ventricle’s ability to pump blood and can lead to heart failure. • Your ejection fraction, which is one of the best indicators of your cardiac performance. Ejection fraction is the percentage of blood your heart is able to pump out of the left ventricle with each beat. The contraction of your heart chambers is called systole, so your ejection fraction is a reflection of your systolic performance. A normal ejection fraction is about 60%.
A low ejection fraction may mean that your heart is not pumping enough blood to meet your body’s needs, and may indicate heart failure. • The functioning of your other heart chambers (left atrium, right ventricle, right atrium), which also indicates your heart’s performance. Heart valves An echo can also evaluate how well a prosthetic valve is functioning. An echo can detect the three main problems that affect heart valves: • Stenosis is a narrowing of the valve, resulting in an insufficient quantity of blood getting through your valve or an increase in the pressure needed to get blood through the valve.
An echo can detect valvular stenosis and assess its severity by: o Showing restricted valve movement. o Measuring the narrowing in the valve opening. o Using a Doppler echo to measure the speed of the blood flowing through the valves and to assess the size of the valve. • Regurgitation means that your valve does not close properly, allowing blood to leak backward into the heart chamber and potentially causing congestion and a backup of blood behind the valve. Doppler echo can be used to detect valvular regurgitation. • Infection can cause inflammation and thickening of the valve.
Heart walls Echocardiography images can help assess how well your heart walls are moving when the chambers of your heart contract. If your heart walls do not move properly, it may indicate that your coronary arteries are not supplying enough blood to your heart muscle. This is a condition called ischemia, which is strong evidence of coronary artery disease. Heart size An echo may be used to evaluate the size of your heart chambers as well as the thickness of your heart walls. • Enlargement of the heart may be associated with heart failure or heart valve problems. Thickened heart walls can indicate cardiomyopathy or a buildup of pressure in the ventricles caused by high blood pressure (hypertension) or heart valve problems.
Alternatively, if your heart wall is too thin, it may indicate damage to the heart muscle from a heart attack. Following a heart attack An echo can be used to evaluate your heart following a heart attack. An echo can: • Identify an area of heart muscle that does not move properly, indicating muscle damage. • Help determine the best course of treatment or evaluate the effectiveness of a particular treatment. Identify and assess complications from a heart attack, such as an aneurysm. How To Prepare Transthoracic echocardiography (TTE) You do not need any special preparation for transthoracic echocardiography. Transesophageal echocardiography (TEE) Do not eat or drink for at least 6 hours before the TEE. If you have dentures or dental prostheses, tell the health professional before the test. You will need to remove them before the test. Before TEE, you will be given a sedative. You will not be able to drive for at least 12 hours after the procedure. Be sure to make arrangements in advance for someone to pick you up after the test.
Stress echocardiography If you are having an exercise echo or dobutamine stress echo, you may be instructed not to eat for several hours before the test. This will help prevent nausea, which can occur while exercising with a full stomach or from the injection of dobutamine. If you are having an exercise stress echo, wear flat, comfortable shoes (no bedroom slippers or sandals) and loose, lightweight shorts or sweatpants. Men are usually bare-chested during the test, while women often wear a bra, T-shirt, or hospital gown. Avoid wearing any restrictive clothing other than a bra.
Before a transesophageal or stress echo test, you will be asked to sign a consent form. Talk to your health professional about any concerns you have regarding the need for the test, its risks, or how it will be done. Complete the medical test information form to help you understand the importance of the test. Why It Is Done Transthoracic echocardiography (TTE) Your health professional may use transthoracic echocardiography to: • Evaluate abnormal heart sounds (murmurs or clicks), a possible enlarged heart, unexplained chest pains, shortness of breath, or irregular heartbeats. Diagnose or monitor a heart valve problem or evaluate the function of an artificial heart valve. • Measure the size and shape of the heart’s chambers.
Echocardiography may be done to detect cardiomyopathy. • Evaluate the ability of your heart chambers to pump blood (cardiac performance). During echocardiography, your doctor can calculate the percentage of blood that the left ventricle of your heart is pumping during each heartbeat (ejection fraction). A low ejection fraction may indicate heart failure. • Detect blood clots and tumors inside the heart.
Transthoracic echocardiography may also be used to: • Evaluate congenital heart defects or to evaluate the effectiveness of previous surgery to repair a congenital heart defect. • Evaluate heart function after a heart attack. • Evaluate the specific cause of heart failure. • Detect pericardial effusion or a thickening of the lining (pericardium) around the heart. • Help diagnose endocarditis. • Evaluate how well the walls of your heart are moving. Areas of your heart muscle that are not moving properly may indicate that the muscle is ot receiving enough blood through your coronary arteries. Transesophageal echocardiography (TEE) Transesophageal echocardiography (TEE) may be done: • To monitor heart function during surgery.
• To evaluate the function of prosthetic heart valves, especially mitral valve prostheses. • To evaluate masses in the upper left chamber (left atrium) of the heart. • To evaluate a problem with blood flow between the chambers of the heart (cardiac shunt). • To help diagnose endocarditis. • When transthoracic echocardiography (TTE) does not provide clear views of the heart. To guide certain procedures done during cardiac catheterization. • To detect a blood clot in the upper chambers (atria) in people with abnormal heart rhythm (arrhythmias). • To help diagnose tearing of the aorta (aortic dissection). Stress echocardiography Stress echocardiography can be done using exercise or with a medication (dobutamine). A stress echo may be done to: • Detect and monitor reduced blood flow to heart muscle (ischemia). Ischemia is usually more apparent after some form of stress, such as exercise or medication. • Assess heart valve disease