As long as this compensation continues, there are no symptoms. If any dilatation occurs from disease, degeneration or from increased work put on the heart (and it is readily seen how delicate this equilibrium is), signs of broken compensation begin to occur. The left ventricle with its enormous strain is perhaps the first part to dilate, thus enlarging the opening of the defective mitral valve. The left auricle is then unable to cope with the increased amount of regurgitant blood, and there is in consequence congestion in the lungs, and the right ventricle finds the pressure ahead in the lungs greater than it can well overcome. The right ventricle, in its turn being overworked, becomes dilated, and as a result of the inability of the right ventricle to evacuate its contents perfectly, the right auricle is unable to force its venous blood into the right ventricle, and there is then a damming back and sluggish circulation in the superior and inferior venae cavae. The results of these circulatory deficiencies are, in the first place, congestion of the lungs and dyspnea; in the second place, with the impaired force of the left ventricle making the arterial circulation imperfect, and with the impaired return of venous blood to the right auricle making the venous circulation sluggish, passive congestions of various organs occur and are evidenced in headache and venous congestion of the eyes and throat, with perhaps cerebral irritability, sleeplessness, and inability to do good mental work. The sluggish return of the blood in the inferior vena cava causes primarily a sluggish portal circulation with a passive congestion and enlargement of the liver. This causes imperfect bile secretion and an imperfect antidotal action to the various toxins of the body or to any alkaloidal drugs or poisons ingested. This congestion of the liver causes a damming back of the blood in the various veins of the portal system, which causes congestion of the stomach and of the mucous membrane of the bowels, and an imperfect secretion of the digestive fluids of these structures. There is also congestion of the spleen. The imperfect return of the blood through the inferior vena cava also interferes with the return of the blood through the renal veins, and more or less renal congestion occurs, with a concentrated urine and perhaps an albuminuria as the result. The same sluggish flow of the inferior vena cava blood, plus the imperfect tone of the systemic arterial system, means that the circulation at the distal portions of the body--the feet and the legs--is imperfect when the patient is up and about, with the result of causing pendant edemas, which disappear at night when the patient is at rest and the heart more easily accomplishes its work.