Mechanical Prosthetic Valves :  These patients should have lifelong anticoagulation. In the absence of anticoagulation systemic embolism and strokes have been reported to be 5-50 percent. Anticoagulants have reduced this incidence to 1-3 per cent per year. However the treatment itself can cause complications. This is related to the level o; anticoagulation. Low level of anticoagulation (INR 2-2.5) has shown to have fewer complications and at the same time as effective in preventing thrombo embolism. Standard anticoagulation (INR 3-4.5) which gives rise to more complications should be limited to high-risk group. It is generally believed that patients with prosthetic aortic valves in sinus rhythm need only lower levels of anticoagulation. In our country where control of anticoagulation is more difficult, a low level of anticoagulation is advisable.