Coronary heart disease (CHD) refers to a mismatch between myocardial oxygen supply and demand. Atherosclerosis is the most important cause. Atherosclerotic changes in coronary vessel walls lead to a narrowing of the lumen and prevent vessels from dilating. As a result, an increase in oxygen demand (e.g., during physical activity) can no longer be satisfied and/or myocardial perfusion at rest is insufficient. Acute retrosternal chest pain (angina) is the cardinal symptom of CHD. Other symptoms include dyspnea, dizziness, anxiety and nausea. If ischemia is severe, myocardial infarction can occur. Coronary heart disease is diagnosed via a cardiac stress test (possibly provoking symptoms and instrumental findings) and/or coronary catheterization (e.g., measurement of coronary blood flow). Management of CHD involves primary and secondary prevention of atherosclerosis (e.g., weight reduction), antianginal treatment (e.g., beta blockers) and, in some cases, revascularization (e.g., PCTA)