Coronary angiography is a specialized, invasive X-ray procedure used to create detailed images of the heart’s blood vessels, known as the coronary arteries. This diagnostic tool allows physicians to directly visualize the blood flow supplying the heart muscle. The main goal is to precisely locate and evaluate any areas of narrowing or blockage within the coronary artery tree.
Why the Procedure is Necessary
The primary reason for performing a coronary angiogram is to diagnose the presence, location, and severity of atherosclerotic disease (plaque buildup) in the heart’s arteries. Doctors typically recommend this test when a person experiences unexplained chest pain (angina), suggesting restricted blood flow. An immediate angiogram may also be prompted by a recent heart attack to identify the blocked vessel. Furthermore, the procedure is used to investigate abnormal results from non-invasive screenings, such as stress tests, or to assess the heart’s condition before major cardiac surgeries like bypass surgery or valve replacement.
Preparing for Your Angiography
Preparation begins by discussing your complete medical history and current medications with your healthcare team. You will be instructed to stop eating or drinking for several hours before the procedure, typically six to eight hours. It is particularly important to review all medications, especially blood thinners like warfarin or clopidogrel, and discuss if they need to be paused. If you have diabetes, your doctor will provide specific instructions for adjusting insulin or other diabetes medications. You must also inform your care team about any known allergies, especially to iodine, shellfish, or the X-ray contrast dye.
The Steps of Coronary Angiography
The procedure takes place in a sterile cardiac catheterization laboratory (“cath lab”). You remain awake, though you may receive a mild sedative to help you relax. The first step involves numbing a small area of skin with a local anesthetic, typically near the wrist or the groin, which are the two most common access sites.
The physician makes a small puncture to insert a sheath, a short hollow tube providing access to the artery. A thin, flexible catheter is then threaded through the sheath and guided toward the heart. Using continuous X-ray imaging (fluoroscopy), the physician watches the catheter’s movement on a monitor to ensure it reaches the openings of the coronary arteries.
Once positioned, a specialized radiopaque contrast dye is injected directly into the coronary arteries. As the dye flows through the vessels, it highlights the inside of the arteries, making any narrowing or blockages immediately visible. The doctor takes multiple X-ray images from various angles to capture a comprehensive view of the entire coronary tree. The entire imaging phase usually takes less than an hour, after which the catheter is removed.
Immediate Recovery and Interpreting Results
After the catheter is removed, pressure is applied to the access site to stop bleeding. If the groin was used, you must lie flat for several hours (often four to six) to minimize bleeding risk. Procedures done through the wrist, a more common approach today, generally require a shorter recovery time. Nurses closely monitor your heart rate, blood pressure, and the access site during this period.
The angiogram images reveal the status of your coronary arteries, showing whether they are clear, partially blocked, or completely closed. If significant blockages are found, the physician may discuss immediate intervention, such as angioplasty and stent placement, which can sometimes be performed during the same procedure. Extensive or complex blockages may lead to a recommendation for coronary artery bypass graft surgery or management with medication.
Understanding Potential Complications
Coronary angiography carries a small risk of complications. The most frequent issue is minor bleeding or bruising at the insertion site, which is usually managed with pressure and rest. A more serious, though rare, access site complication is damage to the artery or a large bruise called a hematoma.
Because the procedure involves injecting contrast dye, a patient may experience an allergic reaction, ranging from mild itching to a more severe response. The dye can also temporarily affect kidney function (contrast-induced nephrotoxicity), especially in people with pre-existing kidney issues. Less common, but serious, risks include heart rhythm disturbances, triggering a heart attack, or a stroke from a dislodged plaque fragment.