What is a coronary CTA?
There is now a way to study the inside of your heart vessels without going inside your heart with a catheter. This new procedure is called a coronary CTA. It is made possible because our new 64 Slice Lightspeed computer tomography (CT) scanner, allows the radiologists and technicians to capture a high-resolution image of the entire heart during 5 heartbeats.
What is the 64 Slice Advantage?
In a single rotation, this new system creates 64 credit card-thin images, totaling 40 millimeters of anatomical coverage. These images are combined to form a three-dimensional view of the patients anatomy for the physician to analyze.
How does the exam work?
Using an IV (small intravenous line), the radiologist and the technologist inject radiographic contrast into your arm vein. The CT scanner, which is monitoring your pulse rate, measures when the contrast will reach your heart vessels. When the contrast is in the heart vessels, the CT scanner takes hundreds of pictures of your heart. The scanner then stacks the pictures together to form a complete picture of your heart.
This picture can be manipulated on a computerized station into a three dimensional image of the heart. This picture can be broken down to show the arteries, muscle, or veins. This reconstruction allows the radiologist to see if you have a blockage of an artery that is causing you to have symptoms related to your heart, such as chest pain. In fact, because the coronary CTA scans most of your chest, the test can be used to check for several different problems that can cause symptoms and may need medical attention.
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How should I prepare for the exam?
PRIOR TO THE EXAM: If you have had a history of cardiac bypass, stent insertion, stress test, cholesterol blood work, or cardiac catheterization within the last year, bring or fax the information to your consulting radiologist.
Preparation for the procedure depends on your symptoms when you arrive for your exam.
If you are having chest pain, call 911 and go to the Emergency Room.
If you have had symptoms in the past and are coming for a coronary CTA as an electively scheduled procedure, follow these instructions:
• Avoid any caffeinated drinks on the day before or the day of your exam, including coffee, tea, energy drinks, or caffeinated sodas (12 hours prior to study).
• Avoid energy or diet pills on the day before or the day of your exam.
• Do not use Viagra, Cialis or any similar erectile dysfunction medication on the day before or the day of your exam. Please avoid these for 48 hours prior to the test as they are not compatible with the medications you will receive during CT scanning of the heart.
• On the day of your exam, do not eat for 4 hours prior to the procedure.
• Drink two 8 ounce glasses of water 1 hour before study
• Take 100 mg of Lopressor orally 1 hour prior to study, this will slightly lower your heart rate. If you suffer from asthma, do not take Lopressor and inform the radiologist or the nurse at the Radiology Department.
•Arrive at the Radiology Department 1 hour before the scheduled time of your exam.
How is the exam performed?
1. You will check in at the Diagnostic Center, Sacred Heart Hospital. A nurse will be assigned to your care.
2. The nurse will establish an IV and prepare you for the exam.
3. You then will be guided to the CT room, where your pulse will be monitored. You will be connected to a 3-lead EKG heart monitor and you will lie on the CT table. The CT table moves you in and out of the scanner as the exam is performed.
4. The CT scan requires the use of contrast material to enhance the visibility of your arteries. Soon after the injection of the contrast, the scan will start.
5. You will be given a squirt of nitroglycerine under your tongue during the exam to dilate the coronary arteries.
6. You will be given oxygen, via a nasal cannula (oxygen tube under your nose), to help you hold your breath when needed during the study.
7. During the scan, you will be asked to hold your breath for about 20 seconds on several occasions.. After that, you will be moved out of the CT room and observed for a few minutes. If you have ever had a CT scan, you will be surprised how much like a regular CT scan this exam seems. In fact, the only difference is the speed of the scanner and the heart monitoring equipment.
Who interprets the results and how do I get them?
A board certified, fellowship trained, radiologist will interpret the results of your exam. If you are actively having chest pain, the radiologist will give your results to the emergency room physician, and a preliminary result will be reported right away. If you are a routinely scheduled patient, the final results will be called / sent to your primary care doctor or cardiologist, who will go over the results at your next office visit.
After the study?
Always make sure to drink plenty of water for 24 hours after the study to help the kidneys excrete the radiographic contrast. You may also return to your usual diet after the procedure.