What is a Heart CT Scan?
Your doctor will order a coronary calcium scan - also called a "heart" or "cardiac" CT scan - to help determine your level of risk for heart disease and heart attack. Using computed tomography, a blend of X-ray technology and computer processing, the scan is used to look for, and measure, calcified plaque in the arteries of the heart. Calcium deposits in the coronary arteries are strong indicators of cardiac problems, and the early detection of cardiovascular disease and its risk factors can be a potential lifesaver.
The Benefits and Risks of a Heart CT Scan
Coronary Calcium Scan Risks
Since computed tomography is partially comprised of X-ray technology, it employs ionizing radiation. The amount, however, is relatively small and does not put your long-term health in jeopardy. In addition, imaging technicians minimize the amount of radiation used by employing the following measures:
- Justification: Doctors limit radiation exposure by only ordering coronary CT scans when patients meet certain guidelines. These include risk factors for heart disease or heart attack.
- Optimization: This is the practice of using the smallest dose of radiation possible to complete the task.
Cardiac CT Scan Side Effects
During some coronary calcium scans, a contrast dye is used to highlight the arteries, veins or other parts of the heart. In rare cases, a patient may be allergic to this dye. When reactions do occur, the side effects are minor - generally including mild hives and itching - and pose no danger to the patient.
The benefits of a cardiac CT scan, in fact, far outweigh the possible side effects, especially when the risk of coronary disease or heart attack is present.
Coronary Computerized Tomography Angiography (Cardiac Coronary CTA test)
Coronary computerized tomography angiography (coronary CTA test) is a noninvasive diagnostic test to evaluate the blood supply through the coronary arteries. This test requires the use of contrast dye which helps highlight the anatomy of the heart and vessels. For patients with symptoms like shortness of breath, chest pain or pressure, a diagnostic coronary exam can help identify the presence of coronary artery disease. Coronary artery disease occurs when the arteries are narrowed or blocked and are restricting blood flow to the heart.
Cardiac Coronary CTA Test vs. Angiogram: What is the difference?
Both tests are designed to identify coronary artery disease by viewing the heart and blood vessels, but they are performed differently. A cardiac coronary CTA test is noninvasive, while a traditional angiogram (cardiac catheterization) is considered minimally invasive.
With a cardiac coronary CTA test, contrast dye is injected through an IV and computerized tomography (CT) images are taken. With an angiogram, a long, thin catheter is inserted into an artery (usually in the groin) and guided to the coronary arteries where X-ray technology is used to obtain images.
Who can benefit from a cardiac coronary CTA test?
If your provider suspects coronary artery disease, you may be advised to undergo a cardiac coronary CTA test. In addition to diagnosing coronary artery disease, this test can also identify other conditions including aneurysm or atherosclerosis.
What to Expect During the Test
A cardiac coronary CTA test usually takes about an hour.
Preparing for the Test
In preparation for the test, your provider will give you specific instructions. You may be asked to do any of the following:
- Temporarily discontinue certain medications
- Avoid caffeine for 12 hours before the test
- Do not eat for 3 to 4 hours before the test
During the Test
An IV will be started in your arm to deliver the contrast dye. Next, the technologist will clean areas on the chest with a cleaning solution and attach electrode sensors to record heart rate and heart rhythm.
The technologist will ask you to lie down flat on your back on the exam table, with your arms raised above your head. You may be given specific breathing instructions to ensure the best possible images.
After the Test
No downtime is needed, and patients can resume normal activities immediately. You should drink plenty of water to help flush the contrast dye from your system.
Test results are usually available within several days. Based on the results, your physician will discuss any additional testing or recommended treatment options.
Risks and Side Effects
Cardiac coronary CTA testing is safe for most people and presents few risks or side effects. If you are allergic to contrast dye, speak with your physician about whether this test is appropriate, or if another option is preferred.
Patients with kidney disease may be at risk of complications from the contrast dye.
Learn more
To learn more about cardiac coronary CTA testing or coronary artery disease, speak with your primary care physician or cardiologist. Based on your specific health needs, your physician may recommend this diagnostic exam.
Other Types of Heart Exams
Stress Test
To help diagnose certain health problems, a stress test is performed. During a stress test a patient will exercise, usually on a treadmill or stationary bike. During the exercise, tests are performed on the heart to find or determine the severity of coronary artery disease.
If a patient is unable to undergo strenuous exercise, the doctor may use medicine to mimic the effects of a workout by making the heart work harder. While this test can be effective in diagnosing some types of cardiac disease, coronary calcium scans often find evidence of disease before it becomes a health threat.
Electrocardiogram (EKG)
An EKG, sometimes known as an ECG, is a fast, portable method for monitoring heart activity and detecting cardiac problems. This noninvasive option, however, does not show the calcium deposits that can signal the early stages of heart disease.
Coronary Angiogram
A coronary angiogram is a type of X-ray imaging that provides a look at the blood vessels of the heart when symptoms of a heart problem occur, or after a stress test shows potential abnormalities. Doctors may also open clogged arteries during the procedure. This type of cardiac catheterization is usually only performed when noninvasive resources have been exhausted. In contrast, cardiac CT scans are noninvasive, provide results in the earliest stages of disease and carry fewer risk factors.
Why Choose Memorial Hermann for Your Cardiac CT Scan?
The affiliated radiologists at Memorial Hermann ensure a high level of accuracy in heart CT scans for our patients, and our hospitals are equipped with advanced, cutting-edge technology.
Schedule your Cardiac CT scan appointment at a convenient Memorial Hermann location near you by calling (877) 704-8700.
