Stress echo/ echocardiography and computed tomography (CT) are tests performed by healthcare providers to diagnose or monitor heart conditions and ensure you get the needed treatment. Before concluding which test is better, we must first understand what these tests mean.

What is a cardiac CT scan?

A cardiac computed tomography (CT) scan is a procedure that uses multiple X-rays from different angles to obtain a high-quality three-dimensional (3D) image of the heart; the scan also picks up significant blood vessels and surrounding structures.

Cardiac CT uses advanced technology with or without intravenous (IV) contrast agents (dyes) to display the heart’s structures and associated blood vessels. Multi-slice scanning allows healthcare providers to acquire high-resolution 3D images of the moving heart and large blood vessels.

What does a CT scan of the heart show?

Your doctor can see the following:

1. Coronary arteries that supply the heart.

2. Ventricles, muscles, valves.

3. Pulmonary vein.

4. Thoracic aorta, sometimes abdominal aorta.

5. The sac around the heart (pericardial sac).

When do you need this procedure?

Cardiac CT scans can provide doctors with more information and detail than other imaging studies. A healthcare provider may want a cardiac CT scan for a variety of reasons, including:

1. Evaluate for causes of chest pain and shortness of breath.

2. The heart arteries are checked for calcium or plaque buildup, narrowing, or blockage.

3. Evaluate heart valves. Check for problems with the aorta, such as an aneurysm or dissection.

4. For planning open chest or minimally invasive/robot-guided heart surgery.

5. For planning transcatheter/percutaneous flap surgery.

6. For planning arrhythmia ablation procedures.

7. Evaluate complications associated with the above procedures. To determine if you have a congenital (at birth) heart defect.

8. Observe and characterise tumours or masses in or around the heart.

9. Look at the sac around the heart for fluid or calcification.

What is a stress echo/ echocardiogram?

An echocardiogram, or echo, is a test that shows how well the heart is functioning. An image of the heart is created using sound waves (ultrasound). These images allow doctors to see the heart and each valve’s shape, size, and movement.

A stress echo assesses the function of the heart when the heart is beating rapidly. You create this “stress” by exercising on a treadmill or bicycle. In most cases, patients will be asked to exercise on a treadmill.

When is the echo stress test performed?

Healthcare providers most commonly use stress echocardiography to diagnose coronary artery disease. This condition occurs when the blood vessels that carry blood to the heart muscle become blocked.

Stress echoes help diagnose or monitor other conditions, such as:

1. Cardiomyopathy.

2. Congenital heart disease.

3. Heart defect.

4. Heart valve disease.

5. Pulmonary hypertension.

Who Should Take the Stress Echo Test?

If you have symptoms of heart disease, especially if your symptoms are made worse by activity, you may have this test. These symptoms are:

1. Chest pain or tightness (angina).

2. Dizziness or lightheadedness.

3. A fast or irregular heartbeat (arrhythmia).

4. Shortness of breath (dyspnea).

Other people who may have a stress echocardiogram include:

1. Athletes.

2. Those who will undergo surgery.

3. People that are exposed to extreme conditions, such as diving or high altitude.

Which is better at identifying heart disease?

In CT scans, clinicians use dye injected into the circulatory system to visualize sudden blockages in arteries. The scan will show a blockage or closing if the dye reaches an impenetrable or narrow passage blocked by fatty deposits or clots.

CT Scan of the heart with the contrast dye

Source: AI to replace contrast dye injections in CT heart scans

A so-called stress test also uses dye, which measures blood flow to the heart muscle immediately after the patient walks on the treadmill. To compare these two methods, the researchers studied 391 symptomatic patients. All patients underwent CT scans and stress tests. Overall, CT scans correctly identified arterial blockages in 91% of patients, while exercise stress testing identified 69%. In a subset of 111 high-risk patients, CT was accurate in 96% of his patients but 80% for exercise testing.

When diagnosing heart disease invasive methods are always more effective than less invasive methods (stress testing).

Despite this, stress testing can still be a more favourable option. As it is much quicker and more accessible, a stress echocardiogram should be your first option to determine your condition. The accuracy results are still similar to those of CT scans. On the other hand, CT scans are more expensive and take longer to get results, but they can also detect more abnormalities than stress tests. If the stress echocardiogram results are negative, consider getting a CT scan if you still have severe heart disease symptoms, e.g. chest pain. Always talk with your doctor before deciding which option you should choose.

The essential difference between the two is that CT scans are more invasive—they require an injection of dye into the body, which can cause problems for people with certain medical conditions. Stress tests do not require injections and can even be done at home in some circumstances if you want to avoid needles.

So which one should you choose?

The answer depends on your needs and preferences. If you don’t mind being poked with needles or using dye, then CT scans might suit you. But if you’re looking for a less invasive way to test your heart health without going to a hospital or getting sick from an unknown substance injected into your body, stress testing may be a better option.

A message from Heartscope Specialist Group

Choosing the proper test can make a big difference in how well your heart is working. but it’s crucial to weigh the pros and cons and get as much information as possible so you can make an informed decision on which test is best for you.

Ultimately, what matters most is that you can choose the option that works best for your needs and preferences. Pay attention to details like the cost of each test, how much time each test will take, and any other factors that may affect your choice.

The stress echo or echocardiogram is often suggested as a good starting point for patients. It is a cost-effective test easily obtained from various healthcare providers, including the Heartscope Specialist Group. However, depending on your specific conditions or circumstances, CT scans might be more suitable for some individuals. It’s important to consult your GP and discuss these options thoroughly before deciding.