Coronary heart disease (CHD), also known as coronary artery disease (CAD) or ischaemic heart disease, is a condition that occurs when the blood vessels supplying the heart muscle (coronary arteries) become narrowed or blocked. This narrowing or blockage can reduce blood flow to the heart muscle, leading to various cardiovascular problems.

Unit 1,

Reference: Oxford Concise Medical Dictionary (9th ed) Oxford University Press 2015 ISBN-13: 9780199687817, p1247