A heart echocardiogram shows the size of your heart chambers, how well your heart muscle pumps, whether your valves open and close properly, and how blood flows through the heart. It uses sound waves (ultrasound) to create real-time images, making it one of the most common and versatile cardiac tests. Most echocardiograms take 30 to 60 minutes, require no radiation, and produce results your cardiologist can interpret the same day.
Heart Pumping Strength and Ejection Fraction
The single most important number from an echocardiogram is your ejection fraction, which tells you what percentage of blood your left ventricle pushes out with each beat. A normal ejection fraction falls between about 55% and 70%. According to 2022 guidelines from the American Heart Association and American College of Cardiology, an ejection fraction of 50% or higher is considered preserved, 41% to 49% is mildly reduced, and 40% or below is classified as reduced, the hallmark of systolic heart failure.
Beyond the overall number, the echo also reveals how individual segments of the heart wall are moving. If a section of muscle isn’t contracting normally, that pattern can point to damage from a heart attack, even an old one you may not have known about. A region that doesn’t move at all typically indicates scar tissue, while a segment that moves weakly may reflect ongoing reduced blood supply or inflammation. These wall motion abnormalities are significant because they predict cardiovascular events independently, sometimes even more reliably than ejection fraction alone.
Chamber Size and Heart Muscle Thickness
An echocardiogram measures all four chambers of the heart. The left ventricle, the main pumping chamber, normally spans about 37 to 53 millimeters across when relaxed, with men trending toward the higher end and women toward the lower end. The right ventricle is smaller, typically 25 to 44 millimeters at its widest point. Both atria (the upper chambers that receive blood) are measured as well, with a normal left atrium running about 27 to 41 millimeters.
When chambers are enlarged, it tells a story. A dilated left ventricle can signal long-standing high blood pressure, valve disease, or cardiomyopathy. An enlarged left atrium often accompanies atrial fibrillation or mitral valve problems. A stretched right side of the heart may point to lung disease or pulmonary hypertension. The echo also measures how thick the heart walls are, which helps identify conditions like hypertrophic cardiomyopathy, where the muscle grows abnormally thick.
Valve Function
Your heart has four valves, and an echocardiogram can assess every one of them in detail. The two most common valve problems are stenosis (a valve that doesn’t open wide enough) and regurgitation (a valve that doesn’t close completely, allowing blood to leak backward). The echo detects both by tracking the speed and direction of blood flow using Doppler ultrasound.
For stenosis, the echo measures how fast blood accelerates through the narrowed opening. Faster flow means a tighter valve. From that velocity, the machine calculates the pressure difference across the valve and estimates the valve’s effective opening area. These numbers are what determine whether stenosis is mild, moderate, or severe. For regurgitation, the echo visualizes the leaking jet of blood flowing in the wrong direction and grades its severity based on how far it extends and how much volume is involved.
This valve information is critical for deciding whether you need monitoring, medication, or eventually surgical repair or replacement.
Blood Pressure Inside the Lungs
An echocardiogram can estimate the pressure in your pulmonary arteries, the vessels that carry blood from the heart to the lungs. It does this by measuring the speed of a tiny jet of blood that leaks backward through the tricuspid valve (most people have a small, harmless amount of this). From that velocity, the machine calculates pressure in the right side of the heart.
Pulmonary hypertension is defined as a mean pulmonary artery pressure of 25 mmHg or higher, and the echo provides a noninvasive way to screen for it. A tricuspid leak velocity of 2.8 meters per second or less suggests normal pressures, while anything above 3.4 meters per second raises a high suspicion for pulmonary hypertension. Other clues the echo picks up include a flattened wall between the ventricles, a dilated right ventricle, or swollen veins entering the heart that don’t collapse normally with breathing.
Fluid Around the Heart
The echo clearly shows the pericardium, the thin sac surrounding the heart. When fluid accumulates in that space, called a pericardial effusion, the echo can detect even small amounts and estimate whether the collection is large enough to compress the heart and interfere with filling. This compression, known as cardiac tamponade, is a medical emergency, and echocardiography is the primary tool used to identify it quickly.
Blood Flow and Structural Connections
Echocardiography produces 2D and sometimes 3D images of the heart walls, valves, and the large blood vessels connected to the heart, including the aorta and pulmonary artery. This makes it valuable for detecting congenital heart defects like holes between chambers or abnormal vessel connections. The Doppler component shows the direction, speed, and turbulence of blood flow in real time, revealing problems that a still image would miss.
What a Standard Echo Cannot Show
Despite its versatility, a standard echocardiogram has blind spots. It cannot directly visualize coronary artery blockages. Cardiac CT and catheter-based angiography are far superior for seeing plaque buildup and narrowing inside the coronary arteries, especially in distal segments that are difficult or impossible to image with ultrasound. An echo can show the consequences of a blockage (a segment of wall that isn’t moving), but it won’t show you the blockage itself.
Certain structures are also hard to see clearly from outside the chest. The left atrial appendage, a small pouch where blood clots often form in people with atrial fibrillation, is one example. A standard transthoracic echo (the type performed on the outside of your chest) often can’t produce clear images of it. A transesophageal echo, where a small ultrasound probe is guided down the esophagus to get closer to the heart, achieves good-quality images of that structure in about 96% of cases. Transesophageal echos are also better for evaluating prosthetic heart valves and detecting infections on valve surfaces.
Types of Echocardiograms
A transthoracic echocardiogram (TTE) is the standard version. A technician applies gel to your chest and moves an ultrasound probe across several positions to capture different views. It’s painless and requires no special preparation.
A stress echocardiogram combines the ultrasound with exercise or a medication that makes your heart beat faster. Images taken before and during stress reveal whether parts of the heart wall stop contracting normally under demand, which suggests restricted blood flow. A transesophageal echocardiogram (TEE) requires mild sedation and produces higher-resolution images of structures that sit near the esophagus, particularly the left atrium, mitral valve, and aorta. Contrast echocardiography uses tiny gas-filled bubbles injected into a vein to improve image quality or detect abnormal blood flow between the right and left sides of the heart.
Which type you receive depends on what your doctor needs to evaluate. For most initial assessments, a standard transthoracic echo provides the information needed to guide the next steps.