Coronary heart condition (CHD), or arteria coronaria disease, develops when the coronary arteries become too narrow. The coronary arteries are the blood vessels that provide oxygen and blood to the guts. It’s usually caused by a build-up of fatty deposits (atheroma) on the walls of the arteries round the heart (coronary arteries). The build-up of atheroma makes the arteries narrower, restricting the flow of blood to the guts muscle. This process is named atherosclerosis.