Angina

Angina pectoris is a symptom of myocardial ischemia: the heart muscle needs more oxygen than the coronary circulation can deliver. It is not synonymous with obstructive coronary artery disease. Ischemia may result from a flow-limiting atherosclerotic lesion, epicardial coronary spasm, coronary microvascular dysfunction, or a supply-demand problem such as anaemia, tachyarrhythmia, severe hypertension, or aortic stenosis. Angina generally occurs without myocardial necrosis, but its symptoms overlap with acute coronary syndrome (ACS), so the pattern and current presentation matter more than the patient’s label. Stable angina follows a reproducible pattern. Exertion or emotional stress increases myocardial demand; pressure, tightness, heaviness, burning, dyspnoea, or another ischemic equivalent appears; stopping the activity and using prescribed short-acting glyceryl trinitrate (GTN, also called nitroglycerin) usually brings relief within minutes. Discomfort may travel to the arm, shoulder, jaw, neck, back, or epigastrium. The Canadian Cardiovascular Society (CCS) grading system describes functional limitation: - Class I: ordinary activity does not cause angina. - Class II: slight limitation of ordinary activity. - Class III: marked limitation of ordinary activity. - Class IV: inability to perform physical activity without...