Q: My 86 years old mother had a pig valve replacement of the mitral valve 13 years back. What are the symptoms if the pig valve replacement begins to fail? Do replaced pig valves degenerate?

A:Yes, biological valves do degenerate, but this is a very gradual process. The symptoms will be mainly a gradual onset of shortness of breath manifested by reduced physical activity, easy fatigability, etc. Your mother may also have associated cough with whitish sputum. Again I stress these symptoms appear very gradually and may not be noticed by the patient for weeks to months.