Angina pectoris. Illustration of a heart diseased with the cardiac condition angina pectoris. The heart is outlined in blue, with the aortic arch at top (red) and coronary arteries at lower frame. A spasm is occurring (centre right, orange) where a coronary artery branch has become pinched between the left atrium and ventricle of the heart. Angina pectoris refers to a pain in the chest due to in- sufficient oxygen reaching the heart muscle. It is caused by coronary artery disease: fat deposits (yellow) develop on the inner walls of the artery (atherosclerosis) decreasing blood flow. Angina pectoris is a common condition, occurring earlier in men. Drug treatment or surgery may be required.