An angiogram is a medical imaging procedure that provides detailed pictures of the body’s blood vessels. This diagnostic test involves injecting a special contrast dye into the bloodstream to highlight the vascular system on real-time X-ray imaging, known as fluoroscopy. The primary purpose of an angiogram is to identify blockages, narrowing, or other abnormalities like aneurysms in the arteries or veins. Visualizing the blood flow allows physicians to accurately determine the location and extent of vascular disease necessary for planning subsequent treatment.
Preparing for the Procedure
Preparation begins before the patient enters the catheterization laboratory. Patients are instructed to stop eating or drinking for several hours before the procedure, typically six to eight hours. This fasting minimizes the risk of aspiration if the patient becomes nauseous or requires unexpected sedation.
A thorough review of the patient’s medical history is completed, paying particular attention to allergies (especially to contrast dye or iodine) and existing kidney conditions. Medication management is another important step, as antiplatelet drugs and blood thinners like warfarin may need to be temporarily stopped or adjusted several days prior to reduce the risk of bleeding. For individuals with diabetes, specific guidance is provided on managing insulin or other medications, particularly since fasting affects blood sugar levels.
The access site, most often the radial artery in the wrist or the femoral artery in the groin, is prepared by cleaning and sometimes shaving a small area of hair to ensure a sterile field. The patient will sign a consent form, confirming they understand the process, potential outcomes, and alternatives. Finally, an intravenous (IV) line is placed to administer fluids, sedatives, and other necessary medications during the procedure.
The Steps of Catheterization and Imaging
Once in the sterile catheterization lab, the patient is positioned on the examination table, and monitoring equipment is attached to track heart rhythm via electrocardiogram (ECG) and continuous blood pressure. A mild sedative is often given through the IV line to help the patient remain relaxed and calm, though they are kept awake to follow simple commands from the medical team. The chosen access site is then numbed with a local anesthetic, which is the only point where the patient is likely to feel a sharp sensation.
The physician makes a small puncture at the access site to introduce a thin, flexible wire into the artery. A short, hollow tube called an introducer sheath is then placed over the wire and into the vessel, serving as a stable entry point for the catheter. The catheter is carefully threaded through the introducer sheath and navigated through the arterial network.
Using real-time X-ray guidance (fluoroscopy), the physician advances the catheter until its tip reaches the blood vessel section intended for examination. When the catheter is positioned correctly, a small volume of iodinated contrast dye is injected. As the dye flows through the vessel, it creates a temporary outline on the X-ray monitor, revealing the vessel’s internal structure and any narrowed segments or blockages. Patients commonly experience a brief, warm flushing sensation throughout their body, or sometimes a feeling like they need to urinate, as the contrast agent circulates. The physician captures multiple diagnostic images from various angles before the contrast material is flushed out.
Immediate Recovery and Post-Procedure Monitoring
After the necessary images are captured, the catheter and the introducer sheath are carefully removed from the access vessel. Achieving hemostasis, or stopping the bleeding at the puncture site, is the immediate priority. This is accomplished either by applying firm manual pressure for 10 to 20 minutes, or by using a specialized closure device, such as a collagen plug or suture-based system.
The patient is then transferred to a recovery area for observation, which typically lasts several hours. Immobility is required during this time, especially if the femoral artery in the groin was used, necessitating lying flat for four to six hours to ensure the artery seals properly. If the radial artery in the wrist was the access site, a compression band is often applied, and the required bed rest is usually shorter.
Medical staff continuously monitor the patient’s vital signs, including heart rate and blood pressure, and check the access site for signs of swelling, bleeding, or hematoma formation. Patients are encouraged to drink extra fluids to help flush the contrast dye out of the kidneys and minimize complications. Before discharge, which often occurs the same day, patients receive instructions regarding wound care, activity restrictions, and signs of complications requiring immediate medical attention.