L13 - Angina Flashcards
What is the definition of angina?
Chest pain caused by myocardial ischaemia due to an imbalance between oxygen supply and demand.
What are the three main types of angina?
- Stable angina: Caused by fixed atheroma and occurs during exertion or stress.
- Unstable angina: Worsening chest pain at rest due to ulcerated atheroma and thrombus formation.
- Prinzmetal’s angina (variant angina): Caused by coronary artery spasm.
What are some classifications of angina beyond the main types?
• Exertional angina: Triggered by exercise or emotion.
• Syndrome X: Microvascular angina with normal large arteries.
• Silent ischaemia: Ischaemia without pain.
• Decubitus angina: Occurs when lying down.
• Nocturnal angina: Wakes the patient at night, often caused by vasospasm.
What causes angina?
• Reduced myocardial blood supply (atherosclerosis, vasospasm).
• Increased extravascular forces (e.g., LV hypertrophy).
• Decreased oxygen-carrying capacity (e.g., anaemia).
• Structural abnormalities (e.g., congenital anomalies, coronary fibrosis).
How is stable angina assessed?
• History: Using the Canadian Cardiovascular Society grading scale (Class I-IV).
• Exercise testing: Induces temporary ischaemia during ECG observation.
• ECG: ST-segment depression during ischaemia.
What are the goals of angina treatment?
• Relieve symptoms (e.g., chest pain).
• Prevent complications like myocardial infarction.
• Improve quality of life and longevity.
What lifestyle changes are recommended to prevent angina?
• Stop smoking.
• Healthy diet (low fat, high fruits/vegetables).
• Moderate alcohol intake.
• Regular exercise and weight control.
What are the pharmacological treatments for stable angina?
• Beta-blockers: Reduce heart rate and contractility.
• Calcium channel blockers: Prevent calcium entry into cardiac and smooth muscle cells.
• Nitrates (e.g., GTN): Relax coronary arteries, reducing preload and myocardial oxygen demand.
• Potassium channel activators (e.g., nicorandil): Hyperpolarise membranes and relax vessels.
How is unstable angina caused?
By rupture of atherosclerotic plaques, exposing contents that lead to thrombus formation and reduced blood flow.
What surgical options are available for angina?
• Percutaneous coronary intervention (PCI): Balloon angioplasty with or without stent placement.
• Coronary artery bypass surgery (CABG): Bypassing blocked coronary arteries.
What is the mechanism of nitrates in angina treatment?
• Donate nitric oxide, stimulating cGMP and reducing intracellular calcium in smooth muscle cells.
• Relax vessels, reducing preload, afterload, and myocardial oxygen demand.
What is the role of antiplatelet and lipid-lowering drugs in angina?
• Antiplatelet drugs (e.g., aspirin): Prevent platelet aggregation.
• Statins: Lower LDL cholesterol and reduce atherosclerosis progression.
