LIFE SAVING TECHNOLOGY THAT HAVE ARISEN AS A RESULT OF IMPROVED UNDERSTANDING OF THE CIRCULATORY SYSTEM (ARTIFICIAL HEART VALVES, ECG AND ARTIFICIAL BLOOD) BY KHRISITIENNE ISON

ARTIFICIAL HEART VALVES An artificial heart valve is a device which is implanted in the heart of someone who suffers from a disease involving a valve in their heart. When one of the valves in the heart malfunctions, the choice is usually to replace the natural valve with an artificial valve. Replacing the valves in the heart requires open heart surgery. There are two types of artificial heart valves: mechanical valves and biological valves. Mechanical heart valves are also called prosthetic heart valves. They are designed to replicate the function of normal heart valves. Modern mechanical valves can last indefinitely but they require lifelong treatment with anticoagulants, such as warfarin. Biological valves are made of tissues, traditionally from pig heart valves. They have the benefit of improved blood flow and a reduced risk of clots forming so they do not require the lifelong use of warfarin. The disadvantage of these valves is that they last only about 15 years before they need replacing.

ELECTROCARDIOGRAPHY (ECG) An electrocardiogram (ECG) is a medical test that detects cardiac (heart) abnormalities by measuring the electrical activity generated by the heart as it contracts. The machine that records the patient’s ECG is called an electrocardiograph. The electrocardiograph records the electrical activity of the heart muscle and displays this data as a trace on a screen or on paper. This data is then interpreted by a medical practitioner. ECGs from normal, healthy hearts have a characteristic shape. Any irregularity in the heart rhythm or damage to the heart muscle can change the electrical activity of the heart so that the shape of the ECG is changed. A doctor may recommend an ECG for patients who may be at risk of heart disease because there is a family history of heart disease, or because they smoke, are overweight, or have diabetes, high cholesterol or high blood pressure.

ARTIFICIAL BLOOD Artificial blood is a life-saving substance that carries oxygen to the body when there is a shortage of red blood cells. Artificial blood has properties that make it more versatile than real blood, including a long shelf life, no need for refrigeration and the ability to be sterilized. In addition, artificial blood does not need to be specifically matched for type. While artificial blood does not perform all the functions of real blood, it carries out the necessary task of bringing oxygen to the cells. The two most common types of artificial blood are HBOCs (hemoglobin-based oxygen carriers) and PFCs (perflourocarbons).