An echocardiogram is an ultrasound scan of the heart, using sound waves to create moving images of its structures and nearby blood vessels. This non-invasive imaging technique allows medical professionals to assess the heart’s size, shape, pumping capacity, and valve function. When a standard echocardiogram doesn’t provide clear enough images, a contrast echocardiogram may be recommended. This involves introducing a contrast agent into the bloodstream to enhance the visibility of the heart chambers and blood flow.
How the Procedure Is Performed
During a contrast echocardiogram, you will be asked to undress from the waist up, put on a hospital gown, and lie on a couch, usually on your left side. Small sticky pads, called electrodes, are placed on your chest to monitor your heart rate and rhythm. A trained echocardiographer applies gel to your chest, which helps the ultrasound probe move smoothly for better picture quality.
The echocardiographer moves a handheld device, called a transducer, over your chest. This transducer emits sound waves that create live pictures on a monitor. To administer the contrast agent, a small, fine tube called an IV line is inserted into a vein in your arm or hand. The contrast agent, often containing tiny microbubbles, is then injected.
These microbubbles reflect sound waves, making the heart chambers and blood flow more visible on ultrasound images. You might feel a cool sensation as the contrast is administered. During the scan, you may be asked to change positions or hold your breath to capture clear images. The entire procedure takes about 30 to 45 minutes.
When Contrast Echocardiography Is Recommended
Contrast echocardiography is often recommended when a standard echocardiogram does not provide sufficient image quality to assess the heart. This can occur in patients with obesity, lung disease, or thick chest walls, which impede ultrasound waves. When two or more segments of the heart’s inner lining (endocardial border) are not clearly visible, contrast agents improve delineation.
The enhanced visibility provided by contrast is useful for evaluating the heart’s pumping function, specifically the ejection fraction, which measures how well the heart pumps blood with each beat. This improved accuracy is important for diagnosing and managing conditions like heart failure or monitoring patients receiving cardiotoxic treatments, such as Herceptin. Contrast echocardiography also aids in identifying blood clots (thrombi) within heart chambers, especially in the left ventricle, and assessing other structural abnormalities like noncompaction cardiomyopathy. It can also be used during stress echocardiography to improve the assessment of regional wall motion and detect myocardial perfusion issues.
Safety Considerations and What to Expect
Ultrasound contrast agents are generally considered safe and well-tolerated. The contrast medium typically leaves the body through the lungs within a few minutes. Some may have mild side effects such as temporary flushing, a metallic taste, warmth, or a slight headache. Less common side effects include blurred vision, a decrease in blood pressure, itching, or general fatigue.
Serious allergic reactions are rare, occurring in less than 1 in 10,000 patients, but medical staff are prepared to manage them. Inform the medical team about any known allergies, especially to perflutren, blood products, or albumin, and any pre-existing medical conditions like heart, lung, or kidney problems before the procedure. After the test, the gel is cleaned off your chest, and the IV line is removed. You may be asked to rest for a short period while your vital signs are monitored, then return to your usual activities.