Circulatory dynamics in osteitis deformans.

In Paget's disease the peripheral blood flow is increased in the bones affected by the disease. Nevertheless the circulatory dynamics of the patients studied at rest are usually not modified significantly. But during exercise, an abnormal augmentation of the cardiac output in regard to the metabolic needs is observed. These findings are similar to those the authors have observed in patients suffering from systemic arteriovenous aneurysms. IN 1945, Edholm, Howarth and McMi-chael4 showed for the first time that the peripheral blood flow was considerably increased in limbs, the bones of which mere affected by active osteitis deformans. On this occasion, they reported the findings in a patient suffering from both congestive heart failure and Paget's disease, in whom they found a very high cardiac output: 13.3 liters per minute. They suggested that the increase in the blood flow in the bones was responsible for the high-output state. Since then, Paget's disease has been placed among the clinical conditions which lead to congestive heart failure accompanied by high cardiac output, the other conditions being systemic arterio-venous aneurysm, beri-beri, severe anemia, hyperthyroidism and emphysema. 8 11 Edholm, Howarth and McMichael believed that osteitis deformans could give rise to conditions similar to those created by systemic arteriovenous aneurysms and that it is probable that direct, communications between arteries and veins exist in the bones of patients with Paget's disease. Though the existence of such fistulas have not been certainly demonstrated ,2 Rutishauser, Veyrat and Rouiller10 have clearly shown histologically that there is an extremely important increase in the vas-cularity of the diseased bones. This considerable augmentation in periosteal vascularity has been also demonstrated in vivo and post-mor-tem by the injection of radio-opaque ma-215 the size of the vessels forming the periosteal plexus has been demonstrated by dissection.3 Recently, Howarth5 has called attention to the presence of a high cardiac output in 5 out of 13 patients with Paget's disease. With the exception of one case in which the cardiac output reached 13.3 liters, the increase of output observed was slight, in particular if one keeps the fact in mind that the observations on these patients were not made under basal conditions. Howarth stated that involvement of 35 per cent of the skeleton by Paget's disease is necessary before an augmentation of cardiac output can be observed; moreover she thought that the disease must be in an active stage, accompanied by a high phosphatase …