With the coronary CT angiography method, which is also known as "virtual angiography", calcium levels in the veins of the patient can be examined and the stenosis caused by these can be evaluated clearly. Although the calcium score is a very important marker, it is not directly related to the severity of coronary artery disease. Sometimes, although there is calcium in the vessels, there is no serious stenosis, but there may be plaques called soft plaques in patients with a calcium score of zero, that is, no lime in their vessels, and even these plaques may cause serious stenosis.
WHAT IS HEART TOMOGRAPHY / CORONARY CT ANGIOGRAPHY?
Cardiac tomography / Coronary CT angiography is a tomographic imaging method using a contrast agent that is used as a guide in the evaluation of anatomical disorders of the heart, especially in coronary arteries, and in the treatment planning of many heart diseases.
WHAT ARE THE APPLICATIONS OF HEART TOMOGRAPHY / CORONARY CT ANGIOGRAPHY? IS IT APPLIED TO WHICH DISEASES?
Cardiac tomography / Coronary CT angiography is a guide for the treatment of many heart diseases such as coronary artery disease, heart membrane diseases, congenital heart diseases, heart masses, valvular and prosthetic valve diseases.
WHAT ARE THE DIFFERENTIAL FEATURES / ADVANTAGES OF HEART TOMOGRAPHY / CORONARY CT ANGIOGRAPHY?
When a successful scan is performed with coronary CT angiography, a high-level image can be obtained, almost as in angiography. Even in angiography, only the inside of the patient's veins can be seen, while the patient's vascular wall can also be seen in coronary CT angiography. Thus, the structure of the plaques in the vessels can be analyzed. Plaque content analysis is important because the extent and character of plaque also provides information on whether the patient falls into the high-risk group. The treatment of the patient is planned according to all these evaluations. Although patients are sometimes at high risk, effort test may be normal. Therefore, coronary CT angiography is recommended if the patient is seen in the risky group by the physician, and sometimes critical strictures may occur in this examination. Drug treatment is initiated or current drug therapy is arranged in patients with moderate or mild plaques, where vascular stenosis does not indicate a critical condition. In addition, Coronary CT angiography is performed in patients with an existing heart disease to see the course of the disease and whether there are additional problems. Coronary CT angiography is not recommended in patients with very small diameter stents. If the stent sizes are suitable, the presence of stenosis can also be checked with Coronary CT angiography.
Coronary CT angiography is sometimes used to measure the amount of calcium in completely occluded vessels, to plan the passages of the wires to be used during the procedure and to determine the treatment strategy. Coronary CT is also important in terms of guiding during angio-difficult procedures. In addition, although it only takes 5-6 minutes, it takes as little as 40 minutes in total with stages such as informing the patient, opening the vascular access, administering the necessary medications and performing the procedure.
The advantages of coronary CT angiography are as follows:
The image quality is very high.
It is preferred frequently in coronary artery disease because it gives high resolution images. It also provides advanced information on anatomy and vascular connections in complicated and simple congenital heart diseases.
It does not cause any discomfort to the patients, as a short time of 5-7 minutes is sufficient for the shooting and there is no noise problem as in MRI.
There is no pain during and after the procedure.
It can be safely applied in patients who have undergone stenting or bypass surgery or in patients with unknown coronary artery disease. Detailed information about coronary anatomy and stenosis levels can be obtained.
HOW IS THE HEART TOMOGRAPHY / CORONARY CT ANGIOGRAPHY PROCESS?
After the patient is given information about the procedure, they are asked to fill in a consent form. Then, if the patient does not have a recent creatinine value measurement, blood is taken from the patient on the day of the procedure and the creatinine value is checked. Creatinine value is important as contrast material will be given during the procedure.
The vascular access of the patient is opened, and the patient is placed on the stretcher in the tomography device. If necessary, medications are given through the vascular access to adjust the heart rate. Breathing commands are explained to the patient. Because, if the patient does not breathe properly and the image cannot be stabilized, there may be situations called "artifact" that reduce the quality of the shooting. In such a case, the procedure will not be valid because the coronary artery structures are very thin structures and a defect in the image may mislead the doctor. For this reason, breath commands are practiced beforehand, and it is checked how much the heart rate drops with breath holding. However, due to the contrast material administered, the patient may have a feeling of warmth, incontinence, and a metallic taste in the mouth. During the procedure, the patient is also informed of these in advance so that the heart rate does not increase and panic. If the patient knows these in advance, there is usually no problem. Since the cardiac tomography process is very short, it is not a problem even for patients with claustrophobia.
Another important issue in tomography is the patient's heart rate. The heart rate is required to be around 60, thanks to the medications that was used before the procedure or with intravenous drugs that day. Otherwise, there may be situations that deteriorate the image quality called artifacts.
In addition to all these, the medications that the patient took before should be questioned in detail. It should definitely be known whether the patient uses some drugs that increase sexual power, especially before the procedure. If the patient has a history of using this group of drugs recently, the doctor decides whether the procedure will be performed or not. Because if these drugs and the sublingual spray to be given to the patient during the procedure are used simultaneously, blood pressure can decrease significantly. This can be life-threatening. For this reason, it is very important for patients who use drugs to increase sexual power to provide information beforehand.
FREQUENTLY ASKED QUESTIONS ABOUT HEART TOMOGRAPHY
WHAT ARE THE DISADVANTAGES OF HEART TOMOGRAPHY / CORONARY CT ANGIOGRAPHY?
There are 2 important points to be considered regarding this issue. Cardiac tomography involves radiation and contrast material can be dangerous in the group of patients with kidney failure. In our center, techniques are applied to ensure that the minimum level of radiation can be received according to the body surface area of our patients, their body structure and the degree of calcification in their veins. The amount of contrast agent is also kept to a minimum, taking into account the characteristics of the patient.
For which patients should cardiac tomography / coronary CT angiography not be applied?
Since contrast material is used in the procedure, patients with chronic renal failure should definitely be decided by the patient's physician and Nephrology after a pre-evaluation. Coronary CT angiography will not give optimal results in patients with small diameter stents. For cancer patients who are preferred not to receive radiation, if tomography is required, it is cautious to take the minimum radiation dose. Apart from this, the procedure can be applied to all patients.
What should be considered after cardiac tomography / coronary CT angiography?
In a patient with kidney problems, fluid may need to be given for a while before and after the procedure. If heart failure is not detected after the procedure, patients are required to drink 2-2.5 liters of water. This application allows the contrast material to be easily removed from the body. After the procedure, patients should not stand up suddenly. First, they are allowed to sit for a while, and their pulse and blood pressure are checked. In cases such as dizziness and low blood pressure, the patient is followed up for the necessary intervention. Then the reporting process can take 1-2 days.
Can one stand next to pregnant or small children after a cardiac tomography?
Since the cardiac tomography does not contain any radioactive material as in the procedures performed in Nuclear Medicine, there is no need to pay special attention to anything after the procedure.
Will there be any pain in the cardiac tomography procedure?
No, no pain is felt.
Is there a risk of allergy in cardiac tomography?
Since allergy may develop due to the contrast material given in the procedure, the patient's allergy history is taken in detail before the application. In case of allergy, the procedure is performed after the protective drugs are given and the patient is kept under surveillance for a longer period after the procedure. In patients with severe allergic history such as anaphylaxis, the Allergy Department is consulted and the precautions that can be taken beforehand are discussed.
Prepared by Memorial Medical Editorial Board.
25 September 2024
11 May 2021
