An echocardiogram, often called an “echo,” is a non-invasive procedure that uses ultrasound technology to create moving pictures of the heart. This test is a fundamental tool in cardiology, visualizing the heart’s structure and assessing its function in real-time. Understanding the report requires knowing the benchmarks that define a normal echocardiogram result.
The Purpose and Process of the Test
The echocardiogram serves two primary purposes: it provides a detailed visualization of the heart’s size and anatomy, and it evaluates the heart’s mechanical ability to pump blood effectively. The test can help diagnose issues like murmurs, unexplained chest pains, or shortness of breath by examining the heart’s walls, valves, and blood flow.
The most common method is the Transthoracic Echocardiogram (TTE), a painless procedure. Minimal preparation is needed, though patients are sometimes advised to avoid caffeine before the test. During the procedure, small patches called electrodes are placed on the chest to monitor the heart’s electrical activity.
A specialized gel is applied to the chest, and a handheld device called a transducer is moved across the area. This transducer emits high-frequency sound waves that bounce off the heart’s structures, and the returning echoes are converted into moving images on a screen. The sonographer will often ask the patient to change positions or hold their breath briefly to get the clearest views. The entire process is usually completed within an hour, and the results are then reviewed by a cardiologist.
Key Structures Assessed by the Echocardiogram
A normal echocardiogram provides clear visual confirmation that the heart’s physical components are correctly shaped, sized, and moving as they should. The report specifically details the appearance of the four chambers and the four valves.
Chamber Size and Wall Thickness
The heart contains four chambers: the upper atria and the lower ventricles. A healthy heart shows a balanced size across all four chambers, with dimensions falling within established reference ranges adjusted for the patient’s body size. For example, the left ventricle, the heart’s main pumping chamber, has a specific normal internal dimension at end-diastole.
The thickness of the muscular walls is also a measure of normalcy, with the left ventricular wall measuring between 6 and 11 millimeters in a healthy adult. When the muscle wall is excessively thick (hypertrophy), it suggests the heart is working too hard, often against high pressure. Conversely, walls that are too thin can indicate a loss of pumping strength.
Valve Integrity
The heart’s function depends on four valves—the mitral, aortic, tricuspid, and pulmonary valves—which open and close to ensure one-way blood flow. A normal valve assessment shows leaflets that are thin and flexible, opening completely to allow blood passage and closing tightly to prevent any backflow.
A normal report notes the absence of stenosis, a narrowing of the valve that restricts blood flow. It will also confirm no significant regurgitation, which describes blood leaking backward through a valve that has not closed fully. The normal appearance is one of synchronized function without obstruction or leak.
Benchmarks for a Healthy Heart
Beyond the visual assessment of structure, a normal echocardiogram is defined by precise, quantitative measurements that demonstrate the heart’s functional efficiency. These measurements establish that the heart is structurally sound and operating with the expected level of power and relaxation.
Ejection Fraction (EF)
The most important metric for assessing the heart’s pumping strength is the Left Ventricular Ejection Fraction (LVEF). LVEF is the percentage of blood the left ventricle ejects with each beat. A normal LVEF falls between 50% and 70%, indicating that a majority of the blood within the chamber is successfully pumped out.
An LVEF of 60%, for example, means that 60% of the blood in the left ventricle is pushed out into the aorta with every contraction. Values falling below the normal range, particularly below 40%, signify a significant reduction in the heart’s ability to pump effectively, which is associated with heart failure.
Doppler Flow Assessment
Echocardiography utilizes Doppler technology to measure the speed and direction of blood moving through the heart’s chambers and valves. A normal assessment shows blood flow that is laminar, meaning it moves smoothly and in a single direction.
The speed of blood flow, known as velocity, is measured, and a normal result falls within established limits for each valve. For instance, a normal aortic valve peak velocity is less than 2.5 meters per second. The pressure difference across the valves, known as the gradient, is also measured, and a normal mean gradient across the mitral valve is very low, less than 2 mmHg.
Relaxation and Filling (Diastolic Function)
A healthy heart must not only contract efficiently (systolic function), but also relax and fill properly (diastolic function). Normal diastolic function means the left ventricle is able to fully relax and draw in blood without the pressure inside the chamber becoming too high.
Diastolic parameters involve several measurements, including the ratio of blood flow waves into the ventricle, known as the E and A waves. A normal diastolic pattern (Grade 0 function) is identified by an E/A ratio greater than 0.8. This is measured along with the heart muscle’s relaxation speed, known as e-prime (e’), where a normal septal e-prime velocity is greater than 8 centimeters per second, confirming quick and effective relaxation.
Pericardial and Aortic Appearance
The echocardiogram also provides a view of the pericardial sac, the thin, protective layer surrounding the heart. A normal finding is the absence of any significant pericardial effusion, which is an abnormal buildup of fluid around the heart. While a very small amount of fluid can be considered trivial, a normal report confirms no evidence of excess fluid that could impede heart function.
The aorta, the body’s largest artery, is measured at various points, such as the aortic root and ascending aorta. Normal aortic dimensions are dependent on the patient’s age and body size. The report confirms that the diameter is within the expected range, showing no sign of abnormal widening or aneurysm.