CTA is a revolutionary CT examination that allows us to take pictures of the inside of blood vessels.  To specifically evaluate coronary (heart) artery disease, the type of CTA the physician may order is known as Coronary Computed Tomography Angiography or CCTA.  CCTA uses a CT scanner to examine the small arteries that supply blood to the heart muscle. Prior to CCTA, to directly look at the blood vessels of the heart, one would have to undergo an invasive (inside the body) procedure called cardiac catheterization. CCTA is a non-invasive (outside the body) way to evaluate the blood vessels of the heart. In some situations a CCTA can be done instead of a cardiac catheterization.

CCTA sees into the wall of the coronary artery and can estimate the extent of coronary disease.  CCTA not only can determine the severity of blockages, but it also directly visualizes the atherosclerotic plaque deposited in the vessel wall. CCTA allows a physician to measure both the amount of calcified plaque in the coronary arteries, which occurs in more chronic coronary artery disease and more importantly, the amount of soft (fatty and fibrous) plaque formation.  Soft plaque is fibrous and fatty material in arteries that has not yet hardened or calcified.  It is the soft plaque (the so-called vulnerable plaque), which is prone to rupture, that is most dangerous and that most often causes a heart attack without lifestyle changes or medical treatment.  CCTA can also create complex 3-dimensional models of the heart and related structures.

Who is a good candidate for CCTA?

• Patients with symptoms that could be due to ischemia (including chest discomfort, shortness of breath with activity, a sudden decrease in the ability to do physical activities) who cannot undergo optimal stress testing due to the inability to exercise or due to an abnormal resting electrocardiogram (ECG)

• Those patients who have had a stress test that could not rule out a problem with blood flow to the heart may also be candidates

• Patients with an acute onset of possible cardiac symptoms to determine if there is coronary disease (usually done in an emergency room setting)

• Those born with possible or known structural defects of the heart, coronary arteries, or the major blood vessels coming from the heart may benefit from CCTA to define the precise anatomy involved with the abnormality

• Patients with a newly diagnosed cardiomyopathy (weak heart muscle), who need an evaluation of the coronary arteries

• Patients with suspected masses or pericardial (covering around the heart) abnormalities who have had an echocardiogram or MRI that could not rule out the suspected disorder

• A patient planning an atrial ablation procedure or placement of a pacemaker lead in the cardiac veins for anatomic mapping before the procedure

Who is not a good candidate for CCTA?

• Patients for whom it would be unsafe to have imaging contrast media or x-rays such as women who are pregnant and patients with abnormal kidney function

• Patients with atrial fibrillation/arrhythmia or low cardiac output

• Patients with reactive airway disease/COPD/asthma

• Patients with a pacemaker/defibrillator

• Patients who are not able to lie flat, follow voice instructions or hold their breath for up to 20 seconds

Equipment

Because CCTA studies require particular imaging techniques, we complete these examinations at our Southside Medical Imaging facility, which has the specialized 64-slice Aquilion^TM CT scanner.  This new technology features high resolution imaging that produces amazingly detailed pictures of small body structures such as blood vessels. Motion-free imaging is a key to performing accurate CCTA and the since the heart is in constant motion, very rapid scanning techniques are needed.  Because of motion, previous CT equipment could not produce quality images of the small heart arteries.  The new 64-slice technology provides the sub-second scanning and specialized software that allows for the fast temporal resolution required to image the heart and blood flow in the major vessels.

Preparation

Wear loose comfortable clothing without metal snaps or zippers to your appointment.  If necessary you will be asked to change into scrubs or a patient gown.  Metal objects including jewelry, eyeglasses, dentures and hairpins may affect the CT images and may need to be removed prior to your examination. You may also be asked to remove hearing aids and removable dental work. Lockers are available for your personal items however, it is recommended that you leave your valuables at home.

CCTA requires the use of an intravenous (IV) contrast media that contains iodine.  Therefore, it is very important that you tell your physician and our staff if you have ever had an allergic reaction to iodine, shellfish or any contrast media and if you have diabetes or kidney problems.

If you are 60 years of age or older, or if you have a condition such as diabetes or kidney disease, a BUN and creatinine blood test is required to assess kidney function prior to receiving CT IV contrast media.

CCTA requires special preparation prior to the examination, which is listed below.  One of our physicians will contact you prior to your appointment to explain the preparation in detail and answer any questions you may have about the procedure. 

• Nothing to eat or drink 4 hours prior to the examination.  You may take your prescribed medications with a small amount of water if necessary.

• No caffeine (in any form) or nicotine products for 12 hours prior to the examination

• Prescription beta blockers may be given before your arrival to stabilize your heart rate during the procedure (discuss with your referring physician)

• No Viagra/Levirta/Cialis medications for 24 hours before or 24 hours after the examination

• No exercise the day of the examination