SIHD and Angina - Presentation and Investigation

Question 1

Describe the pathophysiology of stable angina

Answer 1

• Mismatch between O2 supply and demand

Reduced blood flow;

• Obstructive coronary atheroma
• Coronary artery spasm
• Coronary arteritis

Reduced O2 transport (uncommon);
- Anaemia

Pathologically increased O2 demand (uncommon);

• LVH: pulmonary hypertension, aortic stenosis, hypertrophic cardiomyopathy
• Thyrotoxicosis

Question 2

Discuss the epidemiology and risk factors of stable angina

Answer 2

Non-modifiable;

• Age
• Sex: male, post-menopausal females
• Creed
• Family history

Modifiable;

• Smoking
• Exercise and diet
• DM
• Hypertension
• Hyperlipidaemia
• Hyperglycaemia

Question 3

Know the symptoms of stable angina

Answer 3

Pain;

• Site: retrosternal
• Character: tight, pressure
• Radiation: neck, jaw, down arms
• Aggrevation: exertion, emotional stress (anything that raises HR, SV or BP)
• Relief: GTN on physical rest
• SOB
• Extreme fatigue
• Syncope

Question 4

Discuss relevant investigations of stable angina

Answer 4

• FBC, U&E, LFT, TFT
• CXR
• ECG: normal in 50%, abnormal Q-waves (past MI), high voltages + ST-segment depression (LVH)
• ETT: ST-segment depression for +ve result
• Myocardial perfusion imaging: good for SIHD, use tracer (healthy cells absorb), compare rest and stress images
• CT coronary angiography

Question 5

Describe the non-pharmacological treatment of stable angina

Answer 5

Percutaneous coronary intervention;

• Cross stenotic lesion with guidewire
• Squash atheromatous plaque with ballon and stent
• If stent used, aspirin and clopodigrel
• Effective for symptoms but not prognosis

Coronary artery bypass surgery (CABG);

• Best option for multi-vessel SIHD
• Higher risk but longer lasting benefit
• Better prognosis: >70% stenosis, three vessel, two vessel with stenosis of proximal LAD and <50% EF

Question 6

Know the signs of stable angina

Answer 6

• Tar staining on fingers
• Obesity
• Xanthelasmata, corneal arcus
• Hypertension
• Abdo aortic aneurysm: bruits, reduced/no peripheral pulses
• Diabetic/hypertensive retinopathy on fundoscopy

Exacerbation;

• Pallor of anaemia
• Tachycardic, tremor, hyperreflexia of hyperthyroidism
• Systolic murmur, AS
• Pansystolic murmur of MR
• Signs of heart failure: basal crackles, elevated JVP, peripheral oedema