An echocardiogram is an ultrasound image of the heart. It can help doctors diagnose a range of heart problems.
Doctors use echocardiograms to help them diagnose heart problems, such as damaged cardiac tissue, chamber enlargement, stiffening of the heart muscle, blood clots in the heart, fluid around the heart, and damaged or poorly functioning heart valves.
In this article, we explain how doctors use echocardiograms, what to expect during the test, and how to interpret the results.
Echocardiography uses ultrasound waves to create a picture of the heart, called an echocardiogram (echo).
It is a noninvasive medical procedure that produces no radiation and does not typically cause side effects.
During an echocardiogram, a doctor can see:
- the size and thickness of the chambers
- how the valves of the heart are functioning
- the direction of blood flow through the heart
- any blood clots in the heart
- areas of damaged or weak cardiac muscle tissue
- problems affecting the pericardium, which is the fluid filled sac around the heart
Doctors can use echocardiograms to:
- determine how well the heart is pumping blood
- assess the reasons for an abnormal electrical test of the heart, called an electrocardiogram (EKG)
- diagnose heart disease — including weak pumping or stiffening of the heart muscle, leaky or blocked heart valves, and chamber enlargement — in adults
- locate blood clots or tumors
- assess the pressure in the heart to diagnose a condition called pulmonary hypertension
- identify congenital heart abnormalities in infants and young children
- monitor how well the heart responds to different heart treatments, such as heart failure medications, artificial valves, and pacemakers
A doctor will order an echocardiogram if they suspect that someone has heart problems. Signs and symptoms that may indicate a heart condition include:
Doctors can order different types of echocardiogram, all of which use high frequency sound waves. The common types include those below.
The transthoracic echocardiogram is the most common type of echocardiogram test.
This test involves placing an ultrasound wand called a transducer on the outside of the chest, near the heart. The device sends sound waves through the chest and into the heart.
The application of a gel to the chest helps the sound waves travel better. These waves bounce off the heart and create images of the heart structures on a screen.
A transesophageal echocardiogram uses a thinner transducer that attaches to the end of a long tube. The individual will swallow the tube to insert it into the esophagus, the tube that connects the mouth and stomach, which runs behind the heart.
This type of echocardiogram provides more detailed pictures of the heart compared with the traditional transthoracic echocardiogram because it gives a "close up" view of this organ.
Doctors use doppler ultrasounds to check the flow of blood. They do this by generating sound waves at specific frequencies and determining how the sound waves bounce off and return to the transducer.
Doctors can use colored doppler ultrasounds to map the direction and velocity of blood flow in the heart. Blood that flows toward the transducer appears red, while blood that flows away looks blue.
The results of a doppler ultrasound can reveal problems with valves or holes in the walls of the heart and assess how the blood is traveling through it.
A three-dimensional (3D) echocardiogram creates detailed 3D images of the heart. Doctors can use 3D echocardiograms to:
- assess valve functionality in people who have heart failure
- diagnose heart problems in infants and children
- plan heart valve or structural interventional surgery
- assess the function of the heart in 3D
- image complex structures within the heart
A doctor can order an echocardiogram as part of a stress test. A stress test involves physical exercise, such as walking or jogging on a treadmill. During the test, the doctor will monitor heart rate, blood pressure, and the heart's electrical activity.
A sonographer will take a transthoracic echocardiogram before and after the exercise.
Doctors use stress tests to diagnose:
- ischemic heart disease
- coronary heart disease
- heart failure
- problems affecting the heart valves
Doctors can use a fetal echocardiogram to view an unborn baby's heart. This exam usually takes place at about 18–22 weeks of pregnancy. Echocardiograms do not use radiation, so they are not harmful to the woman or baby.
Echocardiograms are noninvasive and relatively quick procedures that require minimal preparation.
Below, we discuss what to expect before, during, and after an echocardiogram.
In cases where a healthcare professional takes the echocardiogram from the outside of the body, the person will not need to prepare.
For people who get a transesophageal echocardiogram, a doctor will recommend avoiding eating or drinking anything for at least 4 hours before the exam. People can resume eating and drinking about 1–2 hours after the echocardiogram once the local anesthesia has worn off.
During the test
A sonographer will perform the echocardiogram. Sonographers are healthcare professionals who specialize in using ultrasound devices to produce images and videos for diagnostic purposes.
During the test, the person receiving the echocardiogram will remove their clothes from the waist up. They can wear a hospital gown if they wish to cover themselves during the exam.
The sonographer will then instruct the person to lie on a table, on either their back or their left side. They may inject a saline solution or dye into the person's veins, which makes the heart appear more defined on the echocardiogram.
The exact procedure depends on the type of echocardiogram. For instance:
If a doctor ordered a transthoracic echocardiogram, the sonographer will apply a gel to the chest. The sonographer will then move the transducer around the chest to get different images of the heart.
During the exam, the sonographer may ask someone to change positions or take or hold a deep breath. They might press the transducer into the chest to get a better picture of the heart.
A doctor might order a transesophageal echocardiogram if they want more detailed or clearer images of the heart than those that a transthoracic echocardiogram can produce.
During a transesophageal echocardiogram, the person may receive a mild sedative to help relax the muscles in their throat and a local anesthetic to numb the gag reflex.
Once the sedative takes effect, a doctor will guide a small transducer on the end of a long tube down the throat and esophagus until it reaches the back of the heart.
The sonographer will record images of the heart as the doctor moves the transducer around the esophagus. The person should not feel the transducer or the tube in their esophagus after initially swallowing the probe.
After the test
Most people can return to their regular activities after having a transthoracic echocardiogram.
People who have a transesophageal echocardiogram may need to stay at the hospital or healthcare clinic for a few hours after the exam. They may have a sore throat initially, but it should improve within a few hours to a day.
People who received a sedative before the exam should not drive for several hours after the echocardiogram.
After the exam, the sonographer will send the echocardiographic images to the doctor who ordered the test. The doctor will review the images and look for signs of heart problems, such as:
- damaged heart muscle tissue
- thick or thin ventricle walls
- abnormal chamber size
- poorly functioning valves
- decreased pumping strength
- masses in the heart, such as blood clots or tumors
People should not confuse an echocardiogram with another diagnostic test called an EKG. An EKG measures the electrical impulses or waves that travel through cardiac muscle tissue.
The electrical activity in the heart causes the heart muscle tissues to contract and relax, which creates the rhythmic heartbeat that people can hear through a stethoscope.
A trained technician, nurse, or doctor can take an EKG by placing electrodes on the skin of the chest, arms, or legs. These electrodes record electrical activity and send the information to a computer that converts it into a graph, which a doctor can print out.
An echocardiogram presents a very low risk of side effects or complications. A transesophageal electrocardiogram may trigger a person's gag reflex when the sonographer guides the tube down the throat. People may also have a sore throat after the exam.
Very rarely, a serious complication can occur as a result of the transesophageal echocardiogram, such as damage to the throat, vocal cords, or esophagus.
The use of local anesthetics, sedatives, and contrast dyes during the exam may trigger an allergic reaction in some people.
Contrast dyes can cause the following side effects:
Some people may experience changes in blood pressure or a decrease in the supply of oxygen to the heart during a stress test. A stress test will take place in a fully equipped medical facility in case a person experiences any complications during the exam.
Whenever a person receives sedatives, there is a chance that the stomach contents may enter the lungs. To prevent this, the doctor will ask the individual to attend the procedure with an empty stomach.
Doctors use echocardiography to diagnose problems that affect the heart. During the test, a doctor will evaluate how well a person's heart pumps blood.
Doctors can also use echocardiography to look for signs of heart disease, such as weak heart muscle, blood clots inside the heart, or poorly functioning heart valves.
A doctor might order an echocardiogram if a person shows symptoms of heart conditions, such as:
- shortness of breath
- leg swelling
- heart murmurs
- irregular heartbeat
- abnormal blood pressure
In general, the test carries a low risk of significant complications or side effects. However, people may feel some discomfort, and some individuals can have an allergic reaction to the contrast material or anesthetic.