An angiogram is a specialized diagnostic imaging test used to visualize the inside of blood vessels throughout the body. By introducing a contrast material (dye) into the bloodstream, physicians capture detailed X-ray images showing blood flow. It is primarily used when damage, narrowing, or blockage is suspected, helping determine the source and extent of vascular issues.
Situations That Require Angiography
A physician typically orders an angiogram when a patient presents with symptoms or non-invasive test results suggesting impaired blood flow to a major organ. One of the most common indications is unexplained or severe chest pain, known as angina, especially if it occurs at rest or worsens with physical activity. Such pain can be a sign of coronary artery disease, where plaque has narrowed the arteries supplying the heart muscle.
The test is warranted after abnormal preliminary screenings, such as a positive cardiac stress test or an unusual electrocardiogram (EKG). While these non-invasive results suggest insufficient blood flow, the angiogram provides anatomical detail to confirm the precise location and severity of the problem. Symptoms pointing to peripheral artery disease (PAD), including leg cramping or pain (claudication), also necessitate this procedure.
An angiogram is a standard step in assessing patients who have experienced a transient ischemic attack (TIA) or stroke. The procedure evaluates the carotid arteries in the neck for blockages restricting blood flow to the brain. It is also performed before complex surgical procedures, such as heart valve repair, to ensure the coronary arteries are healthy. The test is also used for diagnosing aneurysms (bulges in an artery wall) or vascular malformations in organs like the kidneys or abdomen.
Different Types of Angiography
Angiography is classified based on the specific vascular system being investigated, allowing for a focused diagnostic approach. Coronary angiography is the most common type, concentrating entirely on the arteries that supply blood directly to the heart muscle. This procedure is generally performed in a specialized cardiac catheterization laboratory.
Cerebral angiography focuses on blood vessels in the head and neck, primarily to identify aneurysms or carotid artery blockages that could lead to a stroke. Peripheral angiography is a broader category used to examine arteries and veins in the extremities (arms and legs) and organs like the kidneys or lungs.
Peripheral angiography is a primary tool for diagnosing and planning treatment for peripheral artery disease (PAD). It allows visualization of narrowed or blocked vessels outside of the heart and brain. Although the core principles of using a catheter and contrast dye remain consistent, the anatomical focus dictates the specific approach used.
Understanding the Procedure
Patients are asked to fast for several hours before the procedure to prepare for the contrast dye. The patient is positioned on an X-ray table, and IV lines administer fluids and a mild sedative for relaxation. The patient remains awake during the test, which typically lasts between 30 minutes and an hour.
The physician cleans and numbs a small area of the body, usually in the wrist or groin, using a local anesthetic. A thin, flexible tube called a catheter is then inserted through a small incision into an artery and gently guided toward the target area, such as the coronary arteries. The movement of the catheter is continuously monitored using a real-time X-ray technique called fluoroscopy.
Once the catheter is in position, the contrast dye is injected, which briefly causes a warm sensation as it travels through the bloodstream. The dye makes the blood vessels visible on the fluoroscopy screen, allowing the physician to see any areas of narrowing, blockage, or abnormality. After images are captured, the catheter is removed, and firm pressure is applied to the insertion site to stop bleeding. Patients must often lie flat for a few hours afterward, especially if the groin was used, to ensure the artery seals properly.
How Angiogram Results Guide Treatment
Angiogram images provide precise data on the location and extent of vascular obstruction. Physicians determine the degree of narrowing in an artery, often expressed as a percentage, which guides the next steps. Less severe blockages or those in less critical vessels may lead to a treatment plan centered on medication management and lifestyle changes.
If the angiogram reveals a significant blockage, the physician may immediately transition to an interventional procedure. During this same session, the catheter can be used to perform an angioplasty, where a balloon is inflated to compress the plaque and widen the artery. A small mesh tube called a stent is frequently placed at the site of the blockage to keep the vessel open and maintain proper blood flow.
When blockages are numerous, extensive, or complex, the angiogram may lead to a recommendation for open-heart surgery. This surgical option is typically coronary artery bypass grafting (CABG), which uses a blood vessel from another part of the body to create a new path around the blocked artery. The angiogram serves as a roadmap, ensuring that the treatment is precisely tailored to the patient’s specific vascular anatomy.