Changing character of a murmur in a patient with joint pain and embolic phenomenon indicates the diagnosis of:

The initial symptoms and signs of endocarditis may be caused by direct aerial, valvular, or cardiac damage.Although changing Regurgitant murmur is significant diagnostically, it is the exception rather than the rule. The damage to valve may cause a perforation to develop in a valve cusp, that explains the manifestation of development of new onset murmur.