Cardiac Catheterization
Cardiac catheterization is a diagnostic procedure that provides detailed images of the heart's chambers (atria, ventricles, and valves) and evaluates cardiac function. It involves taking multiple X-rays while injecting a contrast agent into the blood vessels through a catheter that is guided to the heart.
General Description
Cardiac catheterization, also known as a cardiac angiogram, is a procedure used to study the heart's anatomy and function in detail, as well as to treat various heart conditions. X-rays are used to obtain images while one or more catheters (thin, flexible tubes) are inserted into the heart chambers. Through the catheter, different visualization, measurement, or interventional instruments can be introduced to carry out specific procedures.
Cardiac catheterization can be performed on both sides of the heart:
- Right heart catheterization, or hemodynamic study, evaluates the right atrium, right ventricle, and tricuspid valve. It also measures the amount of blood pumped, as well as pressure and oxygen levels within the heart chambers.
- Left heart catheterization examines the left atrium, left ventricle, mitral valve, and aortic valve. This procedure is performed alongside coronary angiography, which evaluates the coronary arteries using X-ray imaging.
When Is It Indicated?
Cardiac catheterization is used to accurately identify and diagnose various heart conditions, including:
- Congenital heart diseases
- Valve abnormalities
- Ventricular septal defects
- Arrhythmias
- Cardiomyopathies
- Pulmonary hypertension
- Blood vessel blockages or narrowings (through angiography)
Additionally, therapeutic cardiac catheterization serves as an alternative to open-heart surgery for procedures such as:
- Extracting heart tissue samples (myocardial biopsy)
- Correcting arrhythmias (cardiac ablation)
- Repairing or replacing heart valves
- Widening narrowed arteries by placing stents
- Repairing congenital malformations, such as patent ductus arteriosus
How Is It Performed?
A plastic sheath is inserted into a vein (for right heart catheterization) or an artery (for left heart catheterization) through a puncture in the groin, neck, or wrist. Using X-ray guidance, the catheter is maneuvered through the bloodstream until it reaches the heart chambers. Once in position, a contrast agent is injected through the catheter—into the left ventricle for right heart catheterization or into the origin of the coronary arteries for an angiogram. The contrast agent, which contains iodine, highlights blood flow and allows visualization of the heart’s movement and function. As the contrast flows, multiple X-rays are taken.
Risks
Cardiac catheterization is a complex yet safe procedure, though mild discomfort, bruising, or minor bleeding at the puncture site is common.
Severe complications, which occur in only a small percentage of cases, include:
- Bleeding
- Blood clot formation
- StrokeStrokeStroke
- Infection at the puncture site
- Catheter-induced damage to blood vessels or the heart
- Chest pain (angina)
- Arrhythmias
- Allergic reaction
- Kidney damage due to the contrast agent
Additionally, cardiac catheterization involves radiation exposure, which slightly increases the risk of developing cancer or other health issues. However, this risk is only significant with repeated exposure.
What to Expect During Cardiac Catheterization
The procedure is performed in a cardiac catheterization laboratory (cath lab). Before entering, the patient must undress, remove all metal objects (as metal is visible on X-rays), and wear a hospital gown.
Once on the examination table, electrodes are placed on the patient to monitor blood pressure and heart rate throughout the procedure.
Before the puncture, the area is shaved and disinfected, and local anesthesia is administered. Depending on the patient's condition, general anesthesia may also be used. Some sensations the patient may experience include:
- A slight pressure during the puncture
- An increased heart rate as the catheters move
- A brief burning sensation when the contrast agent is injected
The patient must remain as still as possible, though they may be instructed to hold their breath, take deep breaths, cough, or move their arms. The procedure generally lasts between one and two hours, depending on its purpose.
After the study, the catheter is removed, and pressure is applied to the puncture site for several minutes to stop bleeding.
- If the puncture was in the wrist, a compression band is applied.
- If the puncture was in the groin, a compression dressing is placed, and the patient must lie flat and remain at rest for several hours (an overnight hospital stay may be required).
Medical Specialties That Order Cardiac Catheterization
The medical specialties that most frequently request cardiac catheterization are cardiology and vascular surgery/angiology.
How to prepare
Before the procedure, blood tests are performed to assess kidney function and blood clotting, and the patient must sign an informed consent form.
The patient should follow these guidelines:
- Fasting: No food or drink for 6 to 8 hours before the procedure.
- Medication: If taking blood thinners, the treatment may need to be adjusted to reduce bleeding risk.
- Health conditions: Inform the doctor if you have diabetes or kidney disease, as the contrast agent can affect kidney function or interact with medications.
- Allergies: Notify the doctor of any allergies to iodine or contrast agents.
- Pregnancy: Radiation exposure can be harmful to a developing fetus.
