Inability of the heart to maintain normal circulation of the blood; there are various causes, but the consequences are always the same. Decompensation on the left-hand side can be caused by abnormalities of the aortal and mitral valves, high blood pressure and cardiac infarction, causing failure of part of the heart muscle of the left ventricle. Right-hand decompensation occurs in conditions of the tricuspid and pulmonary valves, and in pulmonary heart disease. If all heart muscle cells are affected (as in rheumatic fever) both halves of the heart may fail. If a ventricle malfunctions, pressure rises in the associated arteries, causing in the case of left-hand decompensation lung symptoms (shortness of breath, cardiac asthma, cyanosis). Right-hand decompensation causes oedema Heart failure is accompanied by a number of symptoms; they can often be eased by medication.