anticoagulants — medications used to treat or prevent a blood clot. arrhythmia — an irregular or rapid heart rhythm. artery — a vessel through which the blood passes away from the heart to the various parts of the body. atrial fibrillation — an irregular heart rhythm that causes a fluttering sensation. blood clot — a small amount of blood that has formed into a semi-solid mass, which can create a potentially dangerous medical condition if it causes a blockage of blood flow in a vein, vessel, or artery. coronary artery disease — a build-up of cholesterol or other fatty deposits called plaque that can occur on the inner walls of blood vessels and arteries, which in advanced stages causes restriction or blockage of the blood flow to the heart. deep vein thrombosis — the formation of a blood clot in a deep vein. heart attack — a critical medical situation that occurs when the blood supply to the heart is blocked and there is death of heart muscle. heart failure — a chronic condition that occurs when your heart has become weakened due to injury to the heart muscle. As a result, the heart pumps too little blood to meet the body’s needs. heart valve disease — any disorder of the heart valves, which, if they are not working properly, can obstruct the blood flow through the heart or allow blood to leak back into the heart. International Normalized Ratio (INR) — mathematical calculation of the prothrombin time used to standardize the result from one laboratory to another. Point-of-Care Test (POC) — testing performed at the site of patient care. POC fingerstick tests provide the pro-time/INR result in two minutes. prothrombin time (PT) or pro-time — a test that reflects the amount of time it takes for the blood to clot. pulmonary embolism — the closure of the pulmonary (lung) artery or one of its branches by an embolus, which is a mass of clotted blood or other formed elements. stroke — a sudden and severe blockage of the blood flow to the brain. vein — a vessel through which blood passes from various organs back to the heart. vessel — any channel for carrying a fluid, such as blood vessels, which include arteries, arterioles, capillaries, venules and veins.