Stable Angina

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Patient Advice

Definition

Stable Angina is a type of chest pain or discomfort caused by reduced blood flow to the heart muscle, typically triggered by physical exertion or stress and relieved by rest or nitrates. It is a symptom of underlying coronary artery disease (CAD).

Aetiology

The primary cause of stable angina is coronary artery disease (CAD), which results from atherosclerotic plaque build-up in the coronary arteries. Other contributing factors include:

• Coronary Artery Spasm: Temporary narrowing of the coronary arteries.
• Anaemia: Reduced oxygen-carrying capacity of the blood.
• Tachyarrhythmias: Increased heart rate leading to reduced oxygen supply.

Pathophysiology

Stable angina occurs due to an imbalance between myocardial oxygen demand and supply:

• Fixed Atherosclerotic Plaque: Reduces blood flow to the myocardium during exertion or stress.
• Increased Oxygen Demand: Physical activity or emotional stress increases heart rate and myocardial workload.
• Transient Ischaemia: Insufficient blood supply causes chest pain, which resolves with rest or nitrate use.

Risk Factors

Key risk factors include:

• Smoking and excessive alcohol consumption.
• Hypertension and hyperlipidaemia.
• Diabetes mellitus.
• Obesity and sedentary lifestyle.
• Family history of coronary artery disease.
• Advanced age.

Signs and Symptoms

Typical features of stable angina include:

• Chest Pain: Central, tight, or squeezing pain triggered by exertion or stress.
• Radiation: Pain may radiate to the jaw, neck, shoulders, or arms.
• Relief with Rest: Symptoms typically resolve within minutes of stopping activity or using glyceryl trinitrate (GTN).
• Dyspnoea: Breathlessness accompanying chest discomfort.
• Fatigue: Generalised tiredness, especially during exertion.

Investigations

Diagnostic investigations for stable angina include:

• Clinical Assessment: A detailed history and physical examination to identify typical anginal symptoms.
• Electrocardiogram (ECG):
  • May be normal at rest.
  • ST-segment depression or T-wave inversion during episodes of chest pain.
• Exercise Tolerance Test (ETT): Monitors ECG changes during physical activity.
• Blood Tests:
  • Lipid Profile: To assess cardiovascular risk.
  • Renal Function: To guide medication use.
• Coronary CT Angiography: Non-invasive imaging to assess coronary artery stenosis.
• Stress Echocardiography: Evaluates myocardial perfusion and wall motion abnormalities during stress.

Management

1. Acute Management

• Glyceryl Trinitrate (GTN): Sublingual spray or tablet to relieve chest pain.
• Rest: Stop physical activity to reduce myocardial oxygen demand.

2. Chronic Management

• Anti-anginal Medications:
  • Beta-blockers: E.g., bisoprolol to reduce heart rate and oxygen demand.
  • Calcium Channel Blockers: E.g., amlodipine to improve coronary blood flow.
  • Long-acting Nitrates: E.g., isosorbide mononitrate for symptom control.
• Antiplatelet Therapy: Low-dose aspirin to prevent thrombus formation.
• Statins: E.g., atorvastatin to reduce cholesterol and stabilise plaques.
• ACE Inhibitors: E.g., ramipril for additional cardiovascular protection.

3. Specialist Referral

Referral to cardiology for further assessment may be required for patients with severe or refractory symptoms or high cardiovascular risk. Consider coronary angiography or revascularisation procedures such as PCI or CABG.

Patient Advice

Key advice includes:

• Carry glyceryl trinitrate (GTN) spray and use it at the onset of symptoms.
• Adopt a heart-healthy lifestyle, including a balanced diet and regular light exercise.
• Stop smoking and limit alcohol consumption.
• Take prescribed medications consistently and attend follow-up appointments.
• Seek medical attention if symptoms worsen or do not resolve with rest or GTN use.