CT angiography of coronary arteries is an imaging study that allows us to see the anatomy and condition of the coronary arteries, which are the arteries that supply blood to the heart muscle so that it can perform its function.
Why have I been asked for this test?
This study is usually performed in patients in whom it is suspected that there may be disease or alterations in the anatomy of said arteries that could compromise their blood supply. This usually occurs in patients who have presented certain symptoms and/or alterations in a diagnostic test (frequently in a stress test).
What prior preparation does it require?
In order for the scanner to obtain quality images, it is recommended that the heart rhythm be regular and not too high in frequency. Therefore, if your doctor sees it necessary, he will prescribe oral medication to achieve this goal in the hours before performing the test. They must be prescribed with caution in patients with severe asthma or COPD. The most common are atenolol or bisoprolol.
And the day of the test?
The procedure should be performed on an empty stomach except for prescribed medication, which can be accompanied by some water.
A venous line will be placed for the administration of medication if necessary and iodinated contrast to obtain the images.
Immediately before performing the test, if the performing doctor deems it appropriate, he or she can complement the oral medication taken previously with intravenous medication to achieve an adequate heart rate. In addition, a dose of nitroglycerin is usually administered as a sublingual spray to cause dilation of the coronary arteries and improve their visualization. The administration of nitroglycerin is contraindicated if drugs such as sildenafil or tadalafil, frequently used for the treatment of male impotence, have been consumed in the last 24 hours.
Carrying out the test
To take the images you will be asked to breathe in and hold your breath. The time taken to take the images is between 5-10 seconds, during which it is essential to maintain inspiration and remain still. It is common to notice a sensation of heat and the urge to urinate during the passage of the contrast.
Is iodinated contrast safe?
Iodinated contrast can be used safely in patients who do not have severely decreased kidney function or have had a severe allergic reaction to this type of contrast. In any case, proper hydration is recommended in the hours after the test.
If you have had a non-severe allergic reaction in the past and if the test is essential for diagnosis , it is possible to perform the test with premedication.
Your collaboration is important
Following the instructions and recommendations before the test is essential. Together, we can carry out the study safely and obtain high-quality images to arrive at an accurate diagnosis.
By Dr. Alejandro Cebollada, UICAR specialist