<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been experiencing shortness of breath, increased heart rate, and dizziness lately. What could be the problem?  <response>: Based on your symptoms, its possible that you have mitral valve disease. This occurs when the valve between your hearts left atrium and left ventricle doesnt function properly, leading to various symptoms including shortness of breath, increased heart rate, and dizziness. 