ischemic heart disease

Ischemic heart disease (coronary artery disease, CAD) is myocardial ischemia due to reduced blood flow in coronary arteries, typically from atherosclerotic plaque with superimposed thrombosis. Risk factors include smoking, hypertension, dyslipidemia, diabetes, obesity, family history, male sex, and age. Atherosclerosis develops over decades; coronary plaques narrow the lumen and restrict flow. Acute events occur when plaques rupture, triggering platelet aggregation and thrombosis. Acute ischemia causes chest pain (angina) characterized by exertional substernal pressure/tightness with radiation to arm/jaw, relieved by rest or nitrates. Stable angina is predictable exertional ischemia; unstable angina is new-onset or at-rest ischemia (suggests plaque rupture without infarction). NSTEMI involves myocardial injury (troponin elevation) without ST elevation; STEMI involves ST elevation indicating transmural ischemia. Diagnosis: ECG (ST depression, T wave inversion in unstable angina/NSTEMI; ST elevation in STEMI), cardiac biomarkers (troponin, myoglobin), stress testing, or coronary angiography. Management depends on acuity: stable angina treated with beta-blockers, nitrates, calcium channel blockers, and antiplatelet therapy; acute STEMI requires emergency reperfusion (angioplasty or thrombolysis). Chronic management: aspirin, statins, beta-blockers, ACE inhibitors, lifestyle modification. Complications include arrhythmias, heart failure, cardiogenic shock, and sudden death.