Atherosclerotic Cardiovascular Disease
This can result from an accumulation of plaques in the coronary arteries which are the most common ones affected by heart disease. When plaques build up, they start to thicken the tunica intima, and this is thought to part of the natural process of aging. The extent of the calcification (plaque build-up) can vary, and when the calcification becomes very serious, blood supply can be cut off resulting in a myocardial infarction. Symptoms include shortness of breath during exertion, chest pain (angina), weakness, dizziness, and an irregular heartbeat. Treatment usually depends upon the severity of calcification, but usually requires surgery to insert a stint to open the vessel or to bypass the artery with an saphenous vein harvested from the leg.
Figure 6: Histological preparation of a Coronary Artery with the black circle showing severe thickening of the tunica intima, the most inner layer of cells in the artery.
Hemopericardium
This is an accumulation of blood that collects in the pericardial sac and causes pericardial effusion, which is abnormal fluid levels around the heart, as well as cardiac tamponade, where blood will stay in the pericardium. A result is that the ventricles cannot contract and blood will not be able to circulate. This often results as a complication of heart surgery when a bypass procedure has not been sutured air tight, and blood can leak out and accumulate. Emergency surgery is often required to drain the blood.
Figure 7: An accumulation of Blood in the Pericardial Sac, showing the clotted blood.
Figure 8: Histological preparation of an artery which has ruptured at the endothelial layer, allowing blood to leak out causing Hemopericardium.
Ventricular Assist Devices (VADS) and Bioprosthetic Valves
When a patient’s ventricles are unable to pump the blood to the lungs (right ventricle) or the body (left ventricle) due to heart failure, a surgical procedure can be performed to implant a mechanical device that will help to pump blood throughout the body. Older models were quite cumbersome; however newer models can now be contained within the chest cavity.
Bioprosthetic replacement valves can be used to replace heart valves that are not working properly or have been damaged by plaque accumulation and calcification. Usually patients with these procedures done are required to take blood thinning pharmacological agents such as Heparin for their entire lives. These can be either mechanical or obtained using other animal tissue such as bovine.
Figure 9: A Bioprosthetic valve in the heart.
All images obtained from this section were from The Internet Pathology Laboratory for Medical Education
Information from this section was obtained from Bojar, 2005.
