An echocardiogram video is a real-time ultrasound loop of the heart, and reading one means learning to identify the camera angle, recognize the four chambers and valves, spot the rhythm of the cardiac cycle, and understand what the color overlays mean. It looks confusing at first because the heart is shown in cross-section from angles you’ve never seen in a textbook diagram, but each view follows a predictable layout once you know what to look for.
Orientation: The Screen Layout
Every echocardiogram image is a fan-shaped or wedge-shaped slice through the chest. The ultrasound probe sits at the narrow top of the fan, so structures closest to the probe appear at the top of the screen and deeper structures appear at the bottom. The heart itself shows up in shades of gray: dense tissue like valve leaflets and the muscular walls appears bright white, blood-filled chambers appear dark or black, and the pericardium (the sac around the heart) often appears as a bright line at the edges.
A small electrocardiogram (ECG) tracing usually runs along the bottom of the screen. This is your timing reference. The tall spike in the ECG marks the start of each heartbeat, which helps you figure out whether the heart is squeezing (systole) or relaxing (diastole) at any given frame.
The Main Camera Angles
Sonographers capture the heart from several standardized positions. Each one slices the heart at a different angle, revealing different structures. You don’t need to memorize all of them, but three views appear in almost every study.
Parasternal Long-Axis (PLAX)
This is often the first clip in a study. The probe sits just left of the breastbone, and you see the heart sliced lengthwise. From left to right across the screen you can typically identify the right ventricle (the smaller chamber closest to the probe), the thick wall separating the two sides of the heart (the interventricular septum), the large left ventricle, the mitral valve flapping open and shut between the left atrium and left ventricle, and the aortic valve leading out into the aorta. The left atrium sits in the far right or lower portion of the image. This view is the go-to for measuring chamber sizes and watching both the mitral and aortic valves open and close.
Parasternal Short-Axis (PSAX)
Same probe location, but rotated 90 degrees so the heart is sliced like a loaf of bread. At the level of the aortic valve, you see a circular cross-section of the valve with its three leaflets arranged like a Mercedes-Benz logo. The right atrium and right ventricular outflow tract wrap around it. Tilting the probe downward gives you a cross-section at the level of the mitral valve (which looks like a fish mouth opening and closing) or at the level of the papillary muscles, which appear as two bright dots inside the left ventricle. This view is especially useful for checking whether all segments of the left ventricle are squeezing evenly.
Apical Four-Chamber (A4C)
The probe is placed at the bottom tip of the heart, near the left nipple, and aimed upward. This produces the view most people recognize: all four chambers visible at once, arranged like a butterfly. The left atrium and left ventricle appear on the right side of the screen, and the right atrium and right ventricle appear on the left (the image is mirrored). The mitral valve separates the left-sided chambers, and the tricuspid valve separates the right-sided chambers. A thin wall called the interatrial septum divides the two upper chambers. This is the best view for comparing the size of all four chambers at a glance.
Spotting Systole and Diastole
The heart in the video loops continuously, and each cycle has two phases. During diastole (relaxation), the ventricles fill with blood. You can see the mitral and tricuspid valves swing open, and the ventricles expand to their largest size. During systole (contraction), the ventricle walls thicken and squeeze inward, the mitral and tricuspid valves snap shut, and the aortic valve opens briefly to let blood out.
The easiest visual cue is the mitral valve. When its two leaflets fly apart, diastole has begun. When they come together, systole is starting. On the ECG strip at the bottom of the screen, the tall R-wave spike corresponds to the very beginning of systole.
What the Colors Mean
Many clips have a color overlay called color Doppler. This shows the direction and speed of blood flow. The standard convention is simple: red means blood is flowing toward the ultrasound probe, and blue means blood is flowing away from the probe. Lighter shades of red or blue indicate faster flow. If the flow becomes very fast or chaotic, the color display breaks into a turbulent mosaic pattern, often with flashes of green or yellow mixed in. That mosaic is a flag for abnormal flow, such as a leaking valve.
A common beginner mistake is thinking red always means arteries and blue always means veins. It doesn’t. The colors are purely about direction relative to the probe, so the same blood vessel can appear red in one view and blue in another depending on where the probe is aimed.
Checking How Well the Heart Squeezes
The single most important number on an echocardiogram report is the ejection fraction (EF), which estimates what percentage of blood the left ventricle pumps out with each beat. A normal EF is 52% to 72% for men and 54% to 74% for women. An EF of 41% to 51% is mildly reduced, 30% to 40% is moderately reduced, and below 30% is severely reduced.
You can get a rough visual sense of EF by watching the left ventricle in the PLAX or A4C view. In a healthy heart, the walls move briskly inward during systole and the chamber gets noticeably smaller. In a heart with reduced EF, the walls barely move and the chamber stays almost the same size throughout the cycle. Sonographers measure EF precisely by tracing the inner border of the ventricle at its largest (end of diastole) and smallest (end of systole) and calculating the difference.
Wall Motion Abnormalities
In a healthy heart, every segment of the left ventricle thickens and moves inward in a coordinated way during systole. When part of the heart muscle has been damaged by a heart attack or is starved for blood flow, that segment behaves differently. There are three levels of abnormal wall motion to watch for:
- Hypokinesis: The segment moves inward, but less than neighboring segments. It looks sluggish.
- Akinesis: The segment doesn’t move at all. It sits still while the surrounding walls squeeze.
- Dyskinesis: The segment moves in the wrong direction, bulging outward while the rest of the heart contracts inward. This is the most severe pattern.
The PSAX view at the level of the papillary muscles is one of the best views for spotting these differences, because you can see all the wall segments of the left ventricle arranged in a circle and compare them directly.
Reading the Valves
Valve problems fall into two categories: stenosis (the valve doesn’t open well) and regurgitation (the valve doesn’t close well). Each has distinct visual signatures.
A stenotic valve looks stiff. The leaflets may appear thickened, bright white from calcification, or fused together at the edges. In the case of mitral stenosis, the anterior leaflet takes on a characteristic “hockey stick” shape during diastole, bowing forward instead of swinging freely. Color Doppler across a stenotic valve shows turbulent flow (that mosaic pattern) on the downstream side as blood forces its way through a narrowed opening.
A regurgitant valve leaks backward. On the 2D grayscale image you might see a leaflet that doesn’t fully close or that prolapses (flops backward). The real giveaway is color Doppler: you’ll see a jet of color shooting back into the chamber the blood just came from. A small, thin jet usually means mild regurgitation. A wide jet that fills much of the receiving chamber suggests more severe leaking.
Common Artifacts to Ignore
Not everything you see on the screen is real anatomy. Ultrasound produces visual artifacts that can look alarming if you don’t recognize them.
Reverberation artifacts appear as repeated, fading copies of a bright structure, stacked in a ladder-like pattern deeper in the image. They don’t respect the boundaries of actual heart chambers. These are especially common around prosthetic (artificial) valves and pacemaker wires. A reverberation in the left atrium can mimic a blood clot or mass, but the clue is that it moves in perfect parallel with the bright structure above it and sits at exactly double the distance from the probe.
Acoustic shadowing is the opposite: a dark, pie-shaped void behind a very dense structure like a heavily calcified valve or a prosthetic valve. The calcium or metal blocks the ultrasound beam completely, so nothing behind it is visible. This can hide a regurgitation jet on color Doppler, which is why sonographers sometimes switch to a different view to look “around” the shadow.
Key Measurements and Normal Ranges
Echo reports include chamber measurements in millimeters. The left ventricle’s internal diameter in diastole normally averages about 44 mm, with a typical range of roughly 37 to 53 mm. In systole, it shrinks to around 30 mm. The left atrium, measured in the PLAX view, normally runs about 34 mm across, with an upper limit around 41 mm. An enlarged left atrium often signals longstanding high blood pressure or valve disease.
You’ll also see these abbreviations throughout the report:
- LV: left ventricle (the main pumping chamber)
- RV: right ventricle
- LA: left atrium
- RA: right atrium
- IVS: interventricular septum (the wall between the two ventricles)
- LVOT: left ventricular outflow tract (the pathway blood takes leaving the left ventricle)
- MV: mitral valve
- AV: aortic valve
- TV: tricuspid valve
- PV: pulmonic valve
- AR/MR: aortic regurgitation / mitral regurgitation
- TTE: transthoracic echocardiogram (the standard external exam)
Putting It All Together
When you sit down with an echocardiogram video, work through it systematically. First, identify the view by looking at which chambers and valves are visible. Then watch the cardiac cycle a few times: notice how the walls move, whether the motion is symmetric, and whether the valves open and close crisply. If color Doppler is on, look for any turbulent mosaic jets that suggest stenosis or regurgitation. Check the measurements against normal ranges, and pay attention to the ejection fraction as the headline number for overall heart function.
It takes practice. The first few times, the grayscale loops look like a blurry mess. But once your eye learns to find the bright valve leaflets as landmarks and track the walls through systole and diastole, the video starts to tell a coherent story about how the heart is performing.