Cardiac catheterization: what it is, how it is done and care

Cardiac catheterization is an examination carried out by a cardiologist to evaluate the functioning of the heart and changes in the structures of the heart or obstructions in the coronary arteries, allowing the diagnosis and/or treatment of heart diseases, such as acute myocardial infarction, cardiomyopathies or arrhythmias, for example.

This examination consists of introducing a catheter, which is an extremely thin flexible tube, into the artery of the arm or leg, up to the heart, which allows a detailed examination of the interior of the blood vessels and the heart, being able to detect and remove accumulations of fatty plaques or lesions in these regions.

Cardiac catheterization is carried out in the hospital, and can be carried out free of charge by the SUS, as long as there is a medical indication, or carried out in private hospitals, and the results must be analyzed by a cardiologist.

When is indicated

Cardiac catheterization is indicated to diagnose and/or treat various heart conditions, such as:

In addition, cardiac catheterization may be recommended by the doctor to evaluate the heart before heart surgery or heart transplantation. See how a heart transplant is performed.

To prepare for cardiac catheterization, some precautions must be taken, such as:

• Tell your doctor if you are allergic to iodine or any other type of radiological contrast, latex, medicines, such as penicillins, or foods, such as shellfish or seafood, before taking the exam;
• Tell your doctor if you use oral medicines for diabetessuch as metformin (glucoformin or glifage), before taking the exam;
• Inform your doctor about the use of anticoagulant medicationssuch as warfarin, heparin, rivaroxaban, acetylsalicylic acid or clopidogrel, as the doctor may advise you to stop these medications a few days before the exam;
• Bring a list of all medicationsvitamins and nutritional supplements that you take frequently;
• Inform if you have health problemssuch as hyperthyroidism, kidney failure or epilepsy;
• Tell if you are pregnant or plans to become pregnant, in the case of women;
• Fasting completely for about 4 to 6 hours before the exam, as advised by the doctor;
• Take your usual medicines normallywith little water, as per medical advice;
• Avoid taking medications that have not been prescribed by your doctorincluding home remedies and teas;
• Bring a companion on the day of the examas anesthesia or sedation is used;
• Take personal itemssuch as comfortable clothing, toothbrush, soap or slippers, for example, in case you need to be admitted to hospital after catheterization.

In addition, it is important to take all previously carried out exams, such as blood tests, catheterizations, echocardiogram, electrocardiogram, cardiac scintigraphy, stress test, chest X-ray, computed tomography or cardiac magnetic resonance, for example.

If the person is hospitalized and needs to undergo cardiac catheterization, or requires an emergency catheterization, the doctor will request all tests at the hospital and must assess the risk of the test on an individual basis.

How cardiac catheterization is performed

Cardiac catheterization is performed in the hospital by a cardiologist or cardiovascular surgeon by inserting a catheter or probe into the heart.

Before starting the exam, the nurse administers saline solution into the vein, so that the doctor can inject iodine contrast into the vein, which allows for better capture of the image of the heart and blood vessels, or also for light sedation. .

The following steps are then followed:

1. Local anesthesiain the groin or forearm;
2. Making a small cut in the skin from the groin or forearm at the level of the wrist or elbow, so that the doctor can insert the catheter;
3. Insertion of the catheter into the artery (generally, radial, femoral or bracheal) which will be guided by the specialist doctor, to the heart;
4. Location of artery entrances right and left coronary arteries;
5. Iodine contrast injection which allows the visualization of arteries and their clogging points using X-rays;
6. Contrast injection into the left ventricleallowing visualization of cardiac pumping.

The duration of the exam varies according to the ease of catheterization, generally being longer in patients who have already undergone myocardial revascularization surgery.

Normally, the exam does not take more than 30 minutes, after which it is necessary to rest for a few hours and, if there is no problem, you can go home, if you only carried out the catheterization without any other associated procedure.

Procedures during catheterization

During catheterization, the doctor may perform some procedures, if necessary, such as:

• Angiographyto visualize the interior of the blood vessels in more detail and evaluate the arteries and chambers of the heart, aorta and pulmonary arteries, checking if there is any obstruction or change;
• Coronary angioplastyto unblock a coronary vessel and can be performed with the implantation of a stent (metallic prosthesis) or just with the use of a balloon, which with high pressure, pushes the plaques, opening the vessel;
• Percutaneous valvuloplasty with balloon, used to treat heart valve diseases, pulmonary stenosis, aortic stenosis and mitral stenosis;
• Intravascular ultrasoundperformed using a miniature ultrasound at the tip of the catheter, to produce detailed images of the blood vessels, which allows the accumulation of fatty plaques or calcifications in the arteries to be precisely visualized, in addition to allowing the stent to be correctly positioned;
• Optical coherence tomographymade using a laser, which allows images to be produced and photos taken from inside the blood vessels.

Furthermore, during catheterization, the doctor can perform cardiac ablation, to restore the heart’s electrical impulses, or repair defects in heart valves, replace a heart valve or perform a heart biopsy, for example.

Care after the exam

Recovery from cardiac catheterization is quick, and when there are no other complications that prevent it, the person is discharged from hospital the next day with a recommendation to drink water or other liquids, except alcoholic beverages, and urinate frequently to eliminate the rest of the contrast and avoid vigorous exercise or lifting weights for the first 2 weeks after the procedure.

Furthermore, it is important to follow all medical recommendations, taking the prescribed medications at the correct times and eating a healthy diet. See the main foods that are good for the heart.

Possible risks of catheterization

Despite being very important and generally safe, this procedure can pose some health risks, such as:

• Bleeding and infection at the catheter insertion site;
• Injuries to blood vessels;
• Allergic reaction to the contrast used;
• Irregular heartbeat or arrhythmia, which may go away on its own, but may require treatment if it persists;
• Blood clots that can trigger a stroke or heart attack;
• Drop in blood pressure;
• Accumulation of blood in the sac that surrounds the heart, which can prevent the heart from beating normally.

The risks are minimal when the exam is scheduled, in addition, it is usually carried out in well-equipped cardiology reference hospitals, with cardiologists and cardiac surgeons, either through the SUS or privately.

These risks can occur, especially in diabetics, people with kidney failure or over 75 years of age, or even in more serious cases and in the acute phase of myocardial infarction.

Who shouldn’t do

Cardiac catheterization has no absolute contraindications, and the doctor must individually assess the general health status and associated diseases, to check the risk of complications, or other exam options that can be used to evaluate the heart. See the main heart exams.