A coronary angiogram is a diagnostic procedure used to look inside the coronary arteries — the blood vessels that supply the heart muscle with oxygen-rich blood. It is one of the most common cardiac investigations and is frequently performed in the days following a cardiac arrest to identify whether a blocked or narrowed artery was involved.
Why Is It Done?
After a cardiac arrest, one of the key questions the medical team needs to answer is whether coronary artery disease played a role. A blocked coronary artery — the same thing that causes a heart attack — can trigger a cardiac arrest by cutting off blood supply to part of the heart muscle, destabilising its electrical activity. An angiogram allows the team to see exactly what the coronary arteries look like, identify any blockages or narrowings, and decide on the appropriate next steps.
What Happens During the Procedure?
An angiogram is performed in a cardiac catheterisation laboratory (cath lab). A thin, flexible tube called a catheter is inserted into a blood vessel — usually in the wrist (radial approach) or occasionally the groin (femoral approach) — and guided up to the coronary arteries. A contrast dye is then injected through the catheter, which shows up on X-ray imaging and reveals the shape and condition of the arteries in real time.
The procedure is carried out under local anaesthetic and mild sedation. Most people feel little more than some pressure at the insertion site. It typically takes between 30 minutes and an hour, though the preparation and recovery time means you can expect to be in the department for longer.
What the Results Mean
The angiogram images are reviewed by the cardiologist during and after the procedure. The results fall broadly into three categories: the arteries look normal; there are narrowings that can be monitored or managed with medication; or there is a significant blockage that warrants immediate treatment. In the latter case, stenting is often performed as part of the same procedure, without the need to go back to the cath lab separately.
After the Procedure
After the catheter is removed, pressure is applied to the insertion site to prevent bleeding. If the wrist was used, a small compression band is applied for a few hours. Most people are up and moving relatively quickly, and many go home the same day if no intervention was needed. You will be advised not to drive for at least 24 hours and to avoid heavy lifting for a few days.
If a significant blockage was found and treated at the same time, your recovery will follow the guidance relevant to stenting and angioplasty.
Further Information
The NHS website has a comprehensive guide to coronary angiography including what to expect before, during and after the procedure.