Other reasons
Other reasons for coronary insufficiency are a compression of the coronary arteries due to an enlarged left ventricle (left ventricular hypertrophy), a reduced diastolic blood pressure (second value when indicating the blood pressure; it represents the pressure ratios of the venous vascular system) in e.g. a patient with circulatory shock or a shortening of the diastole, the relaxation phase of the heart, in which the coronaries fill with blood. The oxygen supply to the heart is also reduced when the oxygen content of the blood is reduced (hypoxaemia) as a result of lung disease or anaemia. An imbalance between oxygen supply and demand can be caused by an increase in oxygen demand in addition to the reduced supply.
If there are defects in the heart valves (Vitien), cardiac insufficiency or a heart attack, the wall tension of the heart is increased, which causes an increased demand. If the heart has to work overtime, e.g. in the case of long-standing high blood pressure (hypertension), an enlargement of the heart muscle (myocardial hypertrophy) or increased cardiac output due to hyperthyroidism or infections, its oxygen requirement increases. The increasing narrowing of the coronary arteries limits the coronary reserve, i.e. the blood flow in the coronary arteries cannot be adequately increased under stress, resulting in a reduced oxygen supply to the heart. The length of the narrowing point (stenosis) in the vessel as well as the localization of the stenosis are of decisive importance for the prognosis of coronary heart disease.
Vascular Disease
The heart muscle is supplied via the right and left coronary arteries and the ramus circumflexus, which originates from the left coronary artery. Depending on how many of these three large coronary arteries are blocked or constricted, one, two or three vessel disease is referred to as one, two or three vessel disease. The supply of blood to the heart muscle becomes more and more limited as the number of occluded vessels increases, especially when the left coronary artery is affected. This is where the ramus circumflexus, another important supply vessel of the heart, emerges. In stable angina pectoris, the wall deposits of the vessels (plaques) that cause lumen constriction are fixed, i.e. they are firmly attached to the arterial wall.However, if these wall deposits are torn off, unstable angina pectoris or a heart attack is often triggered if the vessel clearing is partially or completely displaced.