- The radiographic, gross, and microscopic appearances shown are characteristic for what process. What acute changes might you see in the heart?
This is pulmonary thromboembolism (pulmonary embolism, or PE). Acute dilatation of the right ventricle, and possible right atrium, with thinning of the ventricular wall, from acute cor pulmonale may complicate this process.
- What do you see in image 2.5 that helps you to date this process and the origin?
Layering of RBC's, fibrin, and WBC's is typical of a recent pre-mortem thrombus, the so called lines of Zahn. Thromboemboli in the lungs usually come from deep veins in the legs, but may also come from the pelvic veins.
- Name as many predisposing conditions as you can think of that could lead to this process.
The three major factors involved in thrombogenesis are stasis, abnormalities in the vessel wall, and alterations in the coagulation system. Conditions associated with high risk of thromboembolism include the postoperative state, pregnancy, use of birth control pills, congestive heart failure, chronic pulmonary disease, fractures or other injuries of the lower extremities, chronic deep venous insufficiency of the legs, prolonged bed rest, and carcinoma.
- What might we see in other sections of the lung that would be related to this process? What are these called? What are the signs and symptoms that should lead you to suspect this process?
You may see evidence of earlier PE's, which consist of thromboemboli in various states of organization, from unorganized clot to thin fibrous bands or endothelialized scars on the vessel walls. The bands are called "fiddle-strings." The sudden onset of severe unexplained dyspnea, syncope, or breathlessness should suggest PE. The most consistent sign is tachycardia.
