What you should know about heart CT scans

New technology allows doctors to find heart problems earlier. Newer CT scanners with heart packages allow doctors to view more detailed images of the heart in a non-invasive way. Previously doctors primarily relied on stress tests, heart caths and ultrasounds to diagnose and treat heart disease. While these tools are still used, the heart CT is becoming the preferred way for doctors to evaluate your heart. Dr. Lauren Stipp, cardiologist at Ascension Medical Group Sacred Heart Cardiology 30A in Watersound, Florida, explains how a heart CT works and what to expect when you get one.

What does a CT scan of the heart show?

A heart CT scan shows a 3D structure of the overall chest. Instead of taking just a flat image of the heart, the way an X-ray would be able to do, this is where we can actually look at all densities and see how blood flow is working in the heart. A cardiac CT is a non-invasive way of doing a cardiac catheterization or looking at the heart arteries. With a heart CT, doctors can look to see if there is any soft or hard plaque. For symptoms like shortness of breath or chest pain, doctors will look to see if there's any kind of blockage in the arteries of the plumbing of the heart. A heart CT is also helpful for patients with arrhythmias who are having procedures to correct their irregular heart beat because it can help to better identify the problem areas through 3D mapping.

Why would a doctor order a heart CT scan?

With the new chest pain guidelines and with the resolution that a cardiac CT has, it is ideal for patients that are younger or have a couple risk factors. These include family history, high blood pressure, diabetes and/or high cholesterol. Risk factors are all reasons that we would be suspicious for coronary artery disease, blockages or plaque of the heart arteries. 

How long does a CT scan of the heart take?

The cardiac CT itself is done very quickly. What takes the most time is preparing the patient to take the best picture possible. The first thing we do is slow down the heart rate a little bit because with every relaxation that the heart has, that's the timing that we take pictures. After we slow your heart rate down and you get on the scanner we give you some IV contrast. That takes about three minutes. We also give you nitroglycerin underneath the tongue and that helps dilate or plump up the arteries, so that we can take really great pictures. 

What are some of the diagnostic benefits of a heart CT?

Before heart CTs, the only way we could really look at heart arteries was with a stress test or with a cardiac catheterization. 

There are pitfalls to every study but specifically for a stress test it can be very difficult for women. We have breasts and that can get in the way and absorb some radiation, which makes it hard to read. For men, sometimes their belly can get in the way. 

Another thing about stress tests is that they typically detect 70-percent or more plaque or blockages. This is the time that people would get symptoms of heart disease. A cardiac CT can detect plaque that is just at 10-percent when most patients are asymptomatic. Plaque build-up can cause heart attacks and heart disease. This is the preventative side of cardiac CT.