Cardiac Catheterization and Angiography Procedure Overview

Cardiac catheterization and angiography are essential procedures in diagnosing and managing cardiovascular diseases. The process typically includes three main stages: preoperative preparation, intraoperative procedure, and postoperative care, followed by specific applications for different types of angiography.

1. Preoperative Preparation

Before the procedure, proper skin preparation is required, including allergy testing for iodine-based contrast agents and penicillin. To reduce the risk of nausea, vomiting, and aspiration due to the contrast medium, patients should fast for at least six hours before the operation. Sedatives such as barbiturates or diazepam may be administered to help the patient relax. Adults typically receive local anesthesia with 1% procaine or 1% lidocaine, while infants and young children may require a combination of intravenous or general anesthesia with local infiltration of 1% procaine.

2. During the Procedure

During the operation, catheters are usually introduced through the femoral artery and vein. In pediatric patients where femoral access is difficult, alternative routes such as the saphenous vein, external jugular vein, or subcutaneous arteries may be used via incision or puncture. Once the catheter reaches the target area, contrast media are injected for imaging.

To prevent clotting within the catheter, it should be flushed with heparinized saline (40 mg heparin in 500 ml saline). When accessing the left heart via the arterial system, an anticoagulant dose of 0.5 ml/kg heparin is given to minimize the risk of thrombosis or embolism. After completing the angiogram, the catheter is withdrawn, and pressure is applied to the puncture site to control bleeding. Compression and dressing should continue until complete hemostasis is achieved, especially after arterial punctures to prevent hematoma formation. If a surgical cut-down was performed, the distal vein may be ligated, and the artery closed using non-invasive vascular sutures before closing the skin.

3. Postoperative Care

Once the patient returns to the ward, close monitoring is essential for the first 4 to 6 hours. Vital signs such as heart rate, respiratory rate, blood pressure, and temperature must be observed to detect any deterioration in cardiac function, arrhythmias, or allergic reactions to the contrast agent. Conscious patients should be encouraged to drink plenty of fluids to aid contrast elimination, while those still under anesthesia should receive IV fluids for the same purpose. The puncture site should be monitored for signs of bleeding.

Patients who underwent femoral vein puncture must remain on bed rest for at least 24 hours, whereas those with femoral artery puncture need 36 hours of bed rest to reduce the risk of hematoma or dissection at the puncture site.

4. Right Heart Angiography

Right heart catheterization is primarily used to:

Confirm congenital heart defects before surgery;

Assess heart murmurs for appropriate treatment guidance;

Evaluate patients with recurring symptoms following previous heart surgery.

5. Left Heart Angiography

This imaging technique helps diagnose:

Mitral valve stenosis or regurgitation;

Aortic valve stenosis or insufficiency;

Congenital heart anomalies;

Primary cardiomyopathies;

Left ventricular aneurysms.

6. Coronary Angiography

Coronary angiography is performed in cases of:

Persistent or severe angina, including post-myocardial infarction cases;

Evaluation after coronary artery bypass grafting (CABG);

Suspected coronary artery malformations;

Atypical presentations suggestive of coronary artery disease.