Dr. Newton discusses noninvasive cardiac testing and imaging

Cardiac tests and imaging help your doctor determine the presence, nature and extent of different kinds of heart disease. Some examples include electrocardiography, echocardiography, stress testing, transesophageal echocardiogram, cardiac computed tomography, and cardiac magnetic resonance imaging. Heart disease is prolific within our society, so it is fortunate that we have numerous noninvasive ways to gather the information necessary to guide decisions about care. Testing and imaging of the heart takes many forms and can be used to determine diagnosis, assess risk, or an aid in the planning process for treatment procedures.

What is the difference between electrocardiography and echocardiography?

Electrocardiography, commonly referred to as an EKG, uses small electrodes placed on the chest to record the electrical impulses traveling through the heart with each beat. The interpretation of these impulses can help physicians diagnose various heart conditions, such as arrhythmia, heart attack, or problems that can lead to heart failure. Where electrocardiography assesses the electrical workings of the heart, echocardiography uses ultrasound to visualize the heart’s structure and mechanical ability. This test can diagnose valve disease, cardiomyopathy, congenital heart disease, and more.

How does a CT scanner work?

Computed tomography scanner employs a rotating x-ray tube to image structures inside the body. As it rotates around a patient, detectors on the opposite sides collect data and send it to a computer. The computer resolves the data as a two or three-dimensional image of the body. The CT scanners we have now have gone through several generations of improvements. Originally, they were quite simple and could only look at the brain, but the technology has advanced to where we can look at practically any part of the body, even the moving heart. The scanners of today are also faster, produce clearer images, and reduce the amount of x-ray exposure needed.

How is CT used in cardiology?

One of the more basic functions of a CT scanner in cardiology is a test called CT coronary calcium scoring. Many of us are gradually accumulating cholesterol plaques in the walls of our arteries as we age. As these plaques grow they induce an inflammatory response that often ultimately results in the deposition of calcium in the walls of the artery. We use this to our medical advantage to predict the coronary/vascular risk of a patient by determining, with only a small amount of x-ray, how much calcium has built up. Pushing the technology even further, we can create a three-dimensional image of the whole heart and even three-dimensional images of the arteries that feed the heart.

What is cardiac MRI?

Magnetic resonance imaging uses magnets and radio waves to generate images of the body. It is an amazing and complex technology that, timed to the rhythm of the heart, can produce beautiful pictures of the moving heart. We can use different imaging sequences to accurately measure blood flow through the valves of the heart, across chambers of the heart, assess viability of threatened heart muscle, and identify abnormal masses in or around the heart. One of its greatest advantages is the unique information it can gather without delivering medical x-ray exposure.