Picture quiz: Stable angina

Case history

A 60 year old woman presented to her general practitioner with nine months' history of chest pain. The pain was worse on exertion and temporarily relieved by glyceryl trinitrate spray. She had a long standing history of hypertension treated with bendrofluazide and hypercholesterolaemia treated with a statin. She was also on aspirin.

An exercise test was arranged which showed sinus tachycardia segment depression in leads I, II, III, and V1-V6, accompanied by chest pain. Following this the investigation shown in figs 1 and 2 was performed. Fig 3 is a graphical representation of the outline of the heart and the major coronary arteries.

Fig.3

(1) What is the investigation shown in figs 1 and 2?

(2) Can you name the structures A, B, and C?

(3) What are the three possible treatment options for this woman now?

(1) Coronary angiography. This test involves injecting radio-opaque dye into the left and right coronary arteries while taking digital x ray images. Each coronary artery is selectively intubated using a preshaped catheter. This is a very fine tube, <2mm in diameter, passed retrogradely into the ascending aorta through either the brachial, radial, or, more commonly, the femoral artery.

A picture of the distribution of any stenoses within the coronary arteries is built up by taking several pictures of each vessel from different projections. Stenoses are seen as narrowings in the column of dye as it passes down the coronary artery (see figs 1 and 2). At the same investigation, dye is often injected under pressure into the cavity of the left ventricle to assess its contractility. This procedure causes an overall mortality of around 1 in 5000. The commonest complication is of haematoma formation at the arterial access point.

(2)

1. Main stem of the left coronary artery. This artery divides into two major branches: the left anterior descending artery (structure D in fig 1), and circumflex (structure E in fig 1). The left anterior descending artery supplies the anterior interventricular septum, anterior left ventricular wall, parts of the right ventricle, and conducting tissue. The circumflex gives off branches to the posterior left atrial wall, left ventricle, sinoatrial node (in a third of people), and atrioventricular node (in 10% of people).
2. Right coronary artery. This artery divides into vessels that supply the right atrium, right ventricle, and sinoatrial node (in half the population). A tenth of people have both the right coronary artery and the circumflex branch of the left coronary artery supplying the sinoatrial node. One of the branches of the right coronary artery—the posterior descending artery—supplies the atrioventricular node in about 80% of the population. Both the right coronary artery and the circumflex branch of the left coronary artery supply the atrioventricular node in about 10% of the population.
3. Catheter in left coronary artery.

(3) For patients with angina and proven coronary artery disease the three treatment options are medical, medical and angioplasty with stenting, and medical and coronary artery bypass grafting.

Lifestyle changes may contribute to management as recognised in the national service framework for coronary heart disease. Patients with ischaemic heart disease should be advised to stop smoking as a priority. A low cholesterol, Mediterranean-type diet, including more fruit, green vegetables, fish, poultry, bread, and cereals, and less meat and dairy fats, is also of proved benefit. Medical treatment is very important both for symptoms and prognosis. Ideal treatment would include aspirin, beta blockers, and a statin.

Angioplasty and stenting involves injecting a metal cylindrical scaffold into the vessel at the site of stenosis in order to squash the atheroma up against the wall and restore luminal area. It has been shown to be a highly effective symptomatic treatment in suitable patients. It is done under local anaesthetic and requires a hospital stay of only one night.

Coronary artery bypass grafting involves major surgery, and its aim is to bypass the stenoses using arterial and venous conduits sawn on to the coronary arteries distal to the stenoses. It is an effective symptomatic treatment and in some patients is also of prognostic benefit.

M G Tryfonides, fourth year medical student, University of Manchester

C S Zipitis, fourth year medical student,
Email: czipitis@hotmail.com

N P Curzen, consultant cardiologist, Manchester Royal Infirmary


studentBMJ 2002;10:171-214 June ISSN 0966-6494