The Comparison of the 3 Minutes Ramp Walk Test With 6 Minutes Walk Test in Stable Patients After Valve Replacement

In view of assessing the uphill walking capacity and to provide a functional stress test with better sensitivity the investigators need a short term functional stress test over the gold standard six minute walk test.... To demonstrate the significance of 3 minutes ramp walk test over 6 minutes walk test as a functional stress test. The investigators hypothesize that the investigators three minutes ramp walk test (3MRWT) will be superior to the existing six minutes level walk test (6MWT) in the measurement of functional capacity of post valve replacement patients.