Ultrasound imaging is one of the most popular diagnosing technologies due to its accuracy, ready accessibility, safety, and cost efficiency. It’s no surprise then that it is the preferred diagnostic test for many serious medical conditions, including heart disease. The use of ultrasound in diagnosing heart disease is steadily increasing and will continue to do so.
Significance of Ultrasound in Heart Disease Diagnosis
Traditional risk prediction models are quite ineffective in predicting heart attack risk. According to a new study published in the Journal of the American College of Cardiology, up to 70 percent of people who have heart attacks are put in the low or intermediate risk category for a heart attack, when traditional risk prediction models are used.
Furthermore, while cardiovascular tests are available for diagnosing heart diseases, these are invasive, unlike ultrasound testing. Moreover, cardiovascular tests are difficult to perform and expensive, compared to ultrasound.
Innovations in ultrasound technology have made ultrasound machines extremely capable of detecting serious medical conditions like heart disease as they provide clear three-dimensional images of the heart and blood vessels and their functioning in real time. In addition, ultrasound testing is targeted and can be used to confirm suspected heart conditions. It is also safe, radiation-free, and cost and time efficient. Most importantly, however, it eliminates the need for invasive testing, saving the patient pain and discomfort.
What Can a Heart Ultrasound Detect
There are several types of ultrasound tests for diagnosing heart ailments. These include but are not limited to cardiac ultrasound, venous Doppler, carotid Doppler, abdominal ultrasound, and intravascular ultrasound.
Doppler ultrasound is extremely effective in diagnosing heart disease as it can show the direction and speed of blood flow through ultrasonic sound waves as they echo off moving objects. It helps detect obstructions to blood flow like blood clots and narrowed blood vessels, among others. On the other hand, cardiac ultrasound imaging helps physicians in detecting problems related to heart function and heart valves.
Furthermore, duplex ultrasound – a combination of advanced technology like Doppler and regular ultrasound – provides a clear view of veins and arteries to assess and calculate the speed of blood flow. In addition, duplex ultrasound being safe and devoid of radiation and contrast dyes, has become the preferred diagnostic test for heart disease.
Cardiac Ultrasound or Echocardiogram
Cardiac ultrasound is also referred to as echocardiogram, cardiac echo, or transthoracic echo (TTE). It uses ultrasonic waves that bounce off the heart to create a moving image of it. It enables physicians to view the heart in motion, including the beating activity. An echocardiogram provides more detailed information and visualization than an x-ray image.
Since it allows physicians to view the anatomy of the heart from many different angles and to observe the heart rhythm, it is regarded as the most effective way to visualize the function and movement of the heart, heart muscle, and heart valves. It’s best for detecting abnormalities related to the structure and function of the heart.
The echo test is paramount in detecting complex and severe heart conditions such as, heart muscle problems like dilated cardiomyopathy or restrictive cardiomyopathy. It also helps detect enlargement of the cardiac chambers, heart rhythm irregularities, and heart valve disease.
When is it Conducted?
The echocardiogram is a suitable screening test in several cases. These include evaluating high-risk cases of heart disease that are devoid of symptoms and detecting structural abnormalities of the heart in suspected cases. Moreover, the echocardiogram is simple to conduct and doesn’t require any prior screening before the test.
A cardiac echo is typically recommended when patients have symptoms such as shortness of breath, fatigue, or fainting. Also, it may be recommended after an electrocardiogram test if it suggests the possibility of a structural heart problem. Since it is safe, radiation-free, and non-invasive, it can be conducted repeatedly over a prolonged period for monitoring the cardiac condition.
Purpose of Echocardiogram
Cardiac echo is used to detect a range of heart conditions. We’ve compiled a brief list of heart ailments that can be detected via cardiac echo:
- Evaluate the overall function of the heart and detect various types of heart diseases
- Congenital heart conditions such as atrial septal defect and tetralogy of Fallot
- Heart valve irregularities such as mitral valve prolapse
- Monitor the progress of heart valve disease over a period
- Irregular heart rhythms such as cardiac arrhythmia
- Evaluate the effectiveness of cardiac treatments and surgeries
- Aortic stenosis can be detected by measuring impaired blood flow. In this case, Doppler is used to measure the speed of blood flow in various areas of the heart.
An echocardiogram is incapable of showing coronary arteries or blockages in the coronary arteries. Therefore, cardiac catheterization is typically used for the same. Moreover, it can be rendered ineffective in visualizing the heart in certain cases of physical variations like a thick chest wall or emphysema. At such times, a transesophageal echocardiogram (TEE), which is an invasive ultrasound, is performed.
Types of Echocardiograms
There are four types of echocardiograms to choose from, based on the nature of heart ailment.
- Transthoracic Echocardiogram: This is the most commonly performed echocardiogram and is typically conducted to detect heart damage and its extent. A hand-held transducer is placed on the chest and as it transmits high-frequency sound waves, these bounce off the heart structures to create images of the heart. Depending on the part of the heart being examined and the machine type, imaging can be two-dimensional or three-dimensional. In rare cases, when the lungs or ribs interfere with the image clarity, a small amount of contrast is injected through an IV for a better view of the internal heart.
- Transesophageal Echocardiogram (TEE): This test is recommended when the transthoracic echocardiogram is unclear. It is used for visualizing the heart structure more clearly, without the interference of the lungs and chest. It’s an invasive test as a transducer is inserted into the esophagus – the food pipe that connects the mouth and stomach. The test is conducted to detect many heart conditions like abnormal heart valves and rhythms, heart murmurs, congenital heart disease, pericarditis, pericardial effusion, infectious endocarditis, and pulmonary hypertension, among others.
- Stress Echocardiogram: As the name suggests, stress echocardiogram needs to be performed when the patient is under physical stress. Therefore, this test is performed while the patient is exercising. It is performed in combination with an echocardiogram at rest, that is, before exercise to compare the two results in the end. It helps in inspecting the motion of the heart and pumping action when the heart is under stress. It is especially important in detecting, say, a lack of blood flow that may not be detected by other cardiac tests.
- Dobutamine Stress Echocardiogram: Another type of stress echocardiogram, the dobutamine stress differs from the stress echocardiogram in that the former uses a drug instead of exercise to stimulate the heart. This is typically used in cases where the patient is unable to exercise on a treadmill or stationary bike. It is used to assess heart and valve function and the extent to which the heart can tolerate activity, based on which the possibility of coronary artery disease is evaluated.
Coronary Artery Disease (CAD)
Coronary artery disease (CAD) is an ailment of the coronary artery – an artery that feeds the heart. It is characterized by hardening and thickening of the walls of the artery and accumulation of plaque around the walls. The condition is called atherosclerosis. The blockage obstructs blood flow, eventually causing a heart attack or stroke.
CAD mostly does not produce symptoms. However, in a few cases, it is marked by symptoms such as shortness of breath with exertion, fatigue, dizziness, palpitations, decreased physical endurance, chest, arm or jaw pain, and even indigestion. CAD can be treated more effectively if it is diagnosed early. Moreover, early treatment can help preempt complications and serious health consequences.
However, the challenge in detecting CAD is that even with a partial blockage, the heart may still receive ample blood supply while at rest and hence, function normally. Therefore, the consequences are felt only under exercise when the heart is under stress.
Therefore, diagnostic tests like echocardiogram and angiogram are especially important as these can detect mild and early stage CAD. Imaging tests help practitioners to examine the structure and function of the heart for irregular rhythm, irregular heart muscle function, narrow blood vessels, and valve problems. Hence, diagnostic imaging is particularly helpful in diagnosing CAD. At times echocardiograms are conducted along with stress tests for evaluating CAD.
Diagnosis of CAD typically requires evidence of significant blockages in the coronary arteries. In some cases, however, a combination of various tests, including blood tests and physical examination, is required.
Other Types of Ultrasound for Heart Disease
The carotid ultrasound is done to assess the risk of stroke. A transducer, which is gently pressed against the sides of the neck, creates images of the arteries. The blood flow through the carotid arteries on both sides of the neck is examined to detect stenosis.
Abdominal ultrasound is useful in screening abdominal aortic aneurysm. The transducer is pressed against the abdomen, creating imaging that helps in examining the blood flow through the abdominal aorta.
The use of ultrasound in diagnosing heart disease will be more widespread with advancing ultrasound technology and changing ultrasound machine trends favoring smaller, cheaper, and more accurate portable ultrasounds. Our National Ultrasound experts can help you select the right ultrasound machine for cardiology, vascular, and many other applications, for your practice. They are trained in evaluating your requirements and options to fit you with exactly what you need at a great price.