41. The pericardial sac is particularly well suited for a valve leaflet due to its extremely durable physical properties. 42. Pericardial effusion etiologies have changed over time and vary greatly depending on geography and the population in question.43. Extension of the lesions into the chest may lead to the development of chylous pleural and pericardial effusions. 44. When pericardial effusion is suspected, echocardiography usually confirms the diagnosis and allows assessment for signs of hemodynamic instability. 45. It appears that the great majority of pericardial valves function correctly until about 6 to 7 years post implantation. 46. Ionescu in Leeds, England, creates the first bovine pericardial heart valve and begins its implantation in humans. 47. Then he cut out a large square, a pericardial window, to prevent fluid from ever building up again. 48. The avian circulatory system is driven by a four-chambered, myogenic heart contained in a fibrous pericardial sac. 49. The benefactor dies, after being initially stabilized following a femoral artery catheterization, from causes attributed to pericardial tamponade. 50. The pericardial valve is not simply another valve, it is the embodiment of a concept of tissue valve construction.
