The underlying disease process of coronary artery disease (CAD) is called arteriosclerosis. This process starts with a weakening of the blood vessel walls, most frequently caused by an insufficient dietary intake of vitamins and other micronutrients. This leads to an underproduction of collagen and other reinforcement molecules in the artery walls and to the initiation of a repair process to compensate for the growing instability of the wall. The arteriosclerotic plaques that – with time – narrow the blood flow in the coronary arteries is essentially an overshooting repair process for the vitamin-deficient coronary artery wall. A heart attack occurs when the already narrowed artery is clogged and the supply of oxygen and nutrients to billions of heart muscle cells is interrupted. Angina pectoris. Angina pectoris is the typical alarm signal for an increased risk of heart attack. Angina pectoris typically manifests as a sharp pain in the middle of the chest, which frequently radiates into the left arm, but can also manifest itself in other (untypical) symptoms.