 Hello, I am Dr. Devananda, Head of the Department of Cardiac Surgery at Manipal Hospitals. I have been practicing cardiac surgery for the last 18 years. There are several diseases which can affect the mitral valve. Some are from the birth, some we acquire as we grow. Now, one of the important causes of mitral stenosis, which means narrowing of the mitral valve in our country still is rheumatic heart disease, which affects in the form of sore throat, produces antibodies which go and finally affects the heart valves. Somehow in the recent years with the widespread use of antibiotics, the incidence of rheumatic fever is coming down. So also the incident of mitral stenosis.