Echocardiography is an imaging test that uses high-frequency sound waves to create real-time, moving pictures of your heart. It shows the heart’s size, shape, and how well it pumps blood, all without radiation or incisions. It’s one of the most commonly ordered cardiac tests and typically takes less than an hour.
How Ultrasound Creates Heart Images
An echocardiogram works on the same principle as sonar. A small handheld device called a transducer sends sound waves into your chest at frequencies between 2 and 12 MHz, far above the range of human hearing (we top out around 20,000 Hz). Those sound waves travel through tissue, bounce off the structures of your heart, and return to the transducer. The machine measures two things: how long the wave took to come back and how much its strength changed along the way.
Since sound travels through blood and soft tissue at a known, constant speed of about 1,540 meters per second, the machine can calculate exactly how far away each structure is. It splits the round-trip travel time in half and plots the reflecting structure at that distance on the screen. Denser tissues reflect more of the wave’s energy, so they appear brighter on the image. Softer or fluid-filled areas reflect less and appear darker. The result is a detailed, real-time video of your heart beating, with valves opening and closing and chambers filling and emptying.
What It Can Detect
Echocardiography reveals both structural problems and functional ones. On the structural side, it can identify thickened or weakened heart muscle (cardiomyopathy), valves that don’t open fully (stenosis), valves that leak backward (regurgitation), and fluid buildup in the sac around the heart (pericardial effusion). All four heart valves can be evaluated individually.
One of the most important numbers an echocardiogram produces is your ejection fraction, which measures what percentage of blood your heart pumps out with each beat. A normal ejection fraction is 50% or higher. Between 41% and 49% is considered mildly reduced, and 40% or below indicates significantly reduced heart function. This single number plays a central role in diagnosing and managing heart failure.
Types of Echocardiograms
Transthoracic (TTE)
This is the standard version and what most people mean when they say “echocardiogram.” A technician places the transducer on the surface of your chest, moving it to different positions to capture views of the heart from multiple angles. It’s painless, requires no special preparation, and poses no risks. You’ll lie on an exam table, usually on your left side, with a few small electrode stickers on your chest to monitor your heart rhythm during the test. At certain points you may be asked to hold your breath or shift position so the technician can get a clearer image.
Transesophageal (TEE)
When standard chest images aren’t detailed enough, a transesophageal echo places the transducer inside the esophagus, directly behind the heart. This eliminates interference from the ribs and lungs, producing sharper images. The TEE probe uses a higher frequency (around 7 MHz compared to 3.5 MHz for a standard TTE), which improves resolution. You’ll need to fast for at least four hours beforehand. A numbing spray is applied to your throat, sedation is given through an IV, and a thin flexible tube is guided down your esophagus. The most common side effects are a sore throat afterward and, rarely, a minor throat injury.
Stress Echocardiogram
A stress echo compares how your heart looks at rest versus under exertion. Images are taken before and immediately after your heart rate is elevated. If you’re able to exercise, you’ll walk on a treadmill with increasing speed and incline. If you can’t exercise, a medication called dobutamine is given through an IV to raise your heart rate and mimic the effects of physical activity. This test is particularly useful for detecting areas of the heart that aren’t getting enough blood flow during exertion, which may not show up on a resting echo.
Doppler and Color Flow Imaging
Most echocardiograms include a Doppler component, which measures the speed and direction of blood flow through the heart’s chambers and valves. Standard Doppler translates flow information into a graph of velocities over time. Color Doppler goes a step further, overlaying color onto the moving image: typically red for blood flowing toward the transducer and blue for blood flowing away. This makes it easy to spot a leaky valve, where a jet of color appears flowing in the wrong direction, or a narrowed valve, where blood accelerates through a tight opening.
Fetal Echocardiography
Echocardiography can also evaluate a baby’s heart before birth. A fetal echo is typically performed between 18 and 24 weeks of pregnancy and provides far more cardiac detail than a routine prenatal ultrasound. It’s not part of standard prenatal care for every pregnancy. It’s ordered when there’s a specific reason to look more closely: a family history of congenital heart defects, an abnormal rhythm spotted on a routine ultrasound, or maternal conditions like diabetes or lupus that raise the risk of heart problems in the baby. Certain medications taken during pregnancy, including some epilepsy drugs and prescription acne treatments, can also prompt a referral.
Safety
A standard transthoracic echocardiogram carries no known risks. Unlike CT scans or cardiac catheterization, it uses no ionizing radiation and no contrast dye. The sound waves are the same type used in pregnancy ultrasounds. The only discomfort is lying still on your side for the duration of the test. Transesophageal echocardiograms carry a small additional risk from the sedation and the probe passing through the throat, but serious complications are rare.
Cost in the United States
Echocardiogram pricing varies widely depending on where you have it done. Data from insurance claims in New Hampshire (covering mid-2023 through mid-2024) showed patient costs ranging from around $340 at the low end to over $4,000 at the high end, with a statewide average of roughly $3,400 before insurance adjustments. What you actually pay depends heavily on your insurance plan, your deductible, and whether the facility is in-network. If cost is a concern, it’s worth comparing prices between hospital-based imaging centers and independent outpatient facilities, which tend to charge less for the same test.