Coronary Angiography

A common procedure (more than 1,500 a year in Northwick Park Hospital). Used to examine the heart arteries for narrowing or blockage. It typically is performed under light sedation and local anaesthesia and takes 20-30 minutes. These days the radial artery in the wrist is most often used, but in some situations we still use the (larger) femoral artery in the groin. A short valved tube (sheath) is placed in the artery. This allows longer tubes (catheters) to pass under XRay control to the heart. Xray dye (contrast) is injected which shows up the heart arteries. After the pictures are taken the catheters and sheath are removed, a tourniquet is placed on the wrist and gradually released over 4 hours. Most people go home on the evening of the procedure.

Risks (from NHS Choices)

  • bruising - it's common to have a bruise in your wrist or arm for a few days
  • allergy to the contrast dye used, causing symptoms such as a rash, wheeze and a headache - this is uncommon, but you should discuss any allergies with your cardiologist (heart specialist) before having the procedure
  •   Serious complicationsIn very rare cases, more serious complications of coronary angiography can occur. These include:
  • damage to the artery in the arm or groin in which the catheter was inserted, with the blood supply to the limb possibly being affected
  •   heart attack–a serious medical emergency where the heart's blood supply is suddenly blocked
  • stroke - a serious medical condition that occurs when the blood supply to the brain is interrupted
  • damage to the kidneys caused by the contrast dye
  • tissue damage caused by X-ray radiation if the procedure is prolonged
  • death The risk of a serious complication occurring is estimated to be less than 1 in 1,000. People with serious underlying heart problems are most at risk

Coronary Angioplasty (Stent)

Our commonest treatment for narrowed or blocked heart arteries (6 X more often than heart bypass surgery). In Northwick Park Hospital we perform more than 500 a year. It may follow on directly after coronary angiography using the same athand similar catheters. Here a fine flexible wire is passed across the narrowing under XRay control. This allows a deflated balloon to be placed in the narrowed part of the artery and inflated. Once the narrowing has been widened a stent may be implanted in the narrowing. This is a flexible tubular metal mesh, typically 3 X 15 mm in size. More than 90% of angioplasties involve use of a stent.

Risks (from NHS Choices)

  • bleeding or bruising under the skin where the catheter was inserted - estimated to occur in more than one in every 20 cases
  • damage to the artery where the sheath was inserted - estimated to occur in less than one in every 100 cases
  •  allergic reaction to the contrast agent used during the procedure - estimated to occur in less than one in every 100 cases
  • damage to an artery in the heart - estimated to occur in less than one in every 350 cases
  •  excessive bleeding requiring a blood transfusion - estimated to occur in less than one in every 100 cases
  • heart attack, stroke or death - estimated to occur in less than one in every 100 cases
My Own Audited Outcomes (378 Angioplasties 2012-14 from

0% major adverse cardiac events (vs 1.55% of peers)
30 day death rate 0.5% (vs 1.25% of peers)

Common Cardiac Tests

12 lead ECG

A simple recording of the electrical activity of the heart from electrodes placed on the skin. Rarely completely diagnostic in its own right, but a valuable compliment to the initial assessment of a person referred with cardiac issues.


An ultrasound examination of the heart using similar technology as is used to assess the growing foetus in the pregnant woman. A 20-minute non-invasive examination provides a wealth of information about the structure of the heart, function of the heart and the status of the heart valves and heart chambers.

24-hour blood pressure monitor

Portable device that allows approximately 40 readings of blood pressure to be taken over a representative 24-hour period. Particularly valuable in patients with difficult hypertension and multiple drug intolerances as well as issues with “white coat” inaccuracies in blood pressure measurement.

24-hour ECG

A portable, high quality ECG recording often used in the first part of diagnosis of palpitation and heart rhythm disorder. A surprisingly large sample (100,000) heartbeats are seen during this period and even in the absence of symptoms, valuable circumstantial evidence will be obtained.

Coronary CT scanning

A powerful test used particularly to assess the status of the heart after arteries in the assessment of chest pain, along with the screening of high risk individuals for the presence of silent coronary heart disease. A non-intrusive test now with an acceptably low radiation dose.

Exercise stress echocardiography

A technically demanding test where heart ultrasound before and immediately after exercise is used to determine whether there is evidence of blockage of the heart arteries causing angina. Northwick Park Hospital Cardiology Department has particular expertise in the area with our senior sonographers and consultants having an international teaching reputation for the performance of this technique. Very valuable in medium and high-risk individuals to assess whether chest pain or breathlessness is due to blockage of the heart arteries. Patients who cannot exercise, may have pharmacological stress (dobutamine) to mimic the effects of exercise if orthopaedic or other issues prevent them from walking at a medium or high intensity on the treadmill.

2017 Dr Nigel Stephens. Website by Kobestarr Digital