Changes in the proportion of types I and III collagen in the left ventricular wall of patients with post-irradiative pericarditis.

Pericardiectomy for post-irradiative constrictive pericarditis achieves poor results because of the extensive damage to the heart and pericardium caused by ionizing radiation. The extracellular structural protein, collagen, is responsible for the functional integrity of the myocardium and allows reversible interdigitation and the transmission of force between contracting myocytes. Collagen concentration and composition were examined in the cardiac tissue of three patients undergoing pericardiectomy and post-irradiative pericarditis. Normal heart tissue was taken at autopsy from patients without cardiac disease and acted as controls. Total collagen concentration (mean(s.e.m.)) was significantly increased in the ventricular tissue of patients with post-irradiative pericarditis compared with that of the controls (119.8(16.6) versus 50.4(5.2) mg/g dry weight, P<0.01). Although there was an increase in concentration of both type I and III collagen, a disproportional increase in type I was observed. The proportion of type III collagen was lower in patients with post-irradiative pericarditis than in the control group (33(2.6)% versus 38.2(3.7)%, P<0.05). The results of the present study suggest that this marked alteration in collagen concentration and proportion may contribute to the impaired diastolic distensibility of the ventricles seen in this group of patients.

Suppressed fibrinolysis after administration of low-dose aprotinin: reduced level of plasmin-alpha2-plasmin inhibitor complexes and postoperative blood loss.

Various clinical investigation have shown that aprotinin therapy reduces bleeding after open-heart operations. In this study low-dose aprotinin, 30,000 KIU/kg in the cardiopulmonary bypass (CPB) priming volume and 7,500 KIU/kg intravenously each hour during CPB, was used in ten patients undergoing primary myocardial revascularization or surgery for valvular diseases. Another ten patients served as controls. Blood loss, platelet count and plasma levels of hemoglobin, antithrombin III, fibrinogen, fibrinogen degradation products (FDP), total plasmin inhibitor and alpha2-plasmin inhibitor-plasmin complexes were evaluated at nine preoperative, intraoperative and postoperative points. Intraoperative and postoperative blood loss was significantly reduced in the aprotinin group. There was no significant difference between the two groups in platelet count and levels of hemoglobin and antithrombin III. A significant increase in FDP during CPB in the control group indicated hyperfibrinolysis. The levels of plasmin inhibitor were significantly reduced during CPB in the control group. The alpha 2-plasmin inhibitor-plasma complex levels, indicating the plasmin activity, were significantly reduced in the aprotinin group. These results confirmed that low-dose aprotinin reduced blood loss with the prevention of hyperfibrinolysis during CPB and demonstrated improved hemostasis.

Combined mitral valve prolapse and atrial septal aneurysm. A cause for embolic events.

The "association" atrial septal aneurysm and mitral valve prolapse is often asymptomatic with an incidence of about 1% in autopsied adults. Occasionally, however, embolic phenomena can occur. The two-dimensional echocardiography allows an accurate diagnosis of these two cardiac lesions when present. In this paper the Authors report on three patients affected by mitral valve prolapse associated with atrial septal aneurysm, one of whom complicated by a cerebral embolism. Owing to the significant incidence of peripheral or cerebral vascular embolic events in this group of patients, the Authors conclude that long-term anticoagulation therapy is mandatory in all cases, whereas a surgical repair could be advisable when a previous embolism or interatrial shunting is demonstrated.