The mitral valve regulates the ?ow of blood from the left atrium to the left ventricle, the main pumping chamber that pumps blood out into the arteries. It is composed of two lea?ets supported by a ?ne structure of stringlike tissues attached to the heart muscles. The mitral valve may be affected by prolapse, regurgitation, […]
Any of the four heart valves (mitral, aortic, tricuspid, or pulmonary) can be defective or become diseased in a variety of ways. The most common problems occur in the mitral and aortic valves, on the left side of the heart. The most typical causes of valve problems are: • Congenital defects, meaning that a person […]
The four valves that control the one-way ?ow of blood through the chambers of your heart open and close with your every heartbeat. These delicate structures deep inside your heart are critical to the meas- ured passage of about 100 gallons of blood every hour. Responding to pressure changes behind and ahead of them, the […]
Cardiologists in some medical centers are exploring two alternatives to coronary bypass surgery in efforts to ?nd less invasive and less expensive ways to treat coronary artery disease. Both of these alternatives are prom- ising, but the results and long-term outcome are still being evaluated. Port-Access Coronary Artery Bypass (PACAB or PortCAB) For this procedure, […]
Coronary artery bypass, which creates new routes for blood to ?ow around or bypass a clogged artery, is a major surgical procedure to restore adequate blood supply to the heart. To perform a bypass, a sur- geon removes part of a vein from the person’s leg or thigh, or an artery from the chest wall […]
Medications and lifestyle changes are not always enough to prevent a heart attack. A person who comes to the hospital with severe angina or a heart attack probably has one or more coronary arteries that are com- pletely blocked. The ?rst priority is to restore blood ?ow immediately, and the next concern is to reduce […]
Blood clots often play a prominent role in cardiovascular disease. In a healthy person, specialized blood cells called platelets have the capacity to form a clot in response to injury, as a way to limit loss of blood. How- ever, in a person with cardiovascular disease, a blood clot that forms abnormally in an artery […]
One function of the liver is the synthesis of urea from various sources of ammonia, most of which come from protein-splitting bacteria in the GI tract. In cirrhosis, there is extensive liver cell destruction and fibrous tissue replacement of areas between nodules of irregularly regenerating liver cells. This architectural distortion also distorts the hepatic venous […]
Serum albumin levels decrease to variable degrees in many severe acute and chronic disorders. Albumin is synthesized in the liver, so most acute or chronic destructive liver diseases of at least moderate severity also result in decreased serum albumin levels. In addition, there may be other serum protein changes. In cirrhosis of moderate to severe […]
Bile acids are water-soluble components of bile that are derived from cholesterol metabolism by liver cells. Two primary bile acids are formed: cholic acid and chenodeoxycholic acid. Both are conjugated with glycine or taurine molecules and excreted from liver cells into bile in a manner similar but not identical to bilirubin excretion. The conjugated bile […]
