12 Key and Core Catalog With a mechanical key system, the level of security is determined by masterkey control. A masterkey system enables facilities of any size to manage the building by defining access by person and by area in increasing levels of complexity. Since BEST invented the standard for masterkey systems, there is no
When they occur in the upper part of the aorta, they are called thoracic aortic aneurysms. Aneurysms can occur anywhere in the thoracic aorta, including the ascending aorta near the heart, the aortic arch in the curve of the thoracic aorta and the descending aorta in the lower part of the thoracic aorta.
It is now recognized that approximately 50 percent of those born with a bicuspid aortic valve also have a dilated ascending thoracic aorta (the part of the aorta arising from the heart and going up the front of the chest).earn how physicians at the Massachusetts General Hospital Thoracic Aortic Center diagnose and treat thoracic aortic disease, a condition that affects the portion of the aorta that is in the chest and requires treatment from both cardiac and vascular specialists.