A heart murmur
, like a fever
or a cough
, is a very non specific sign that warrants further evaluation. It is simply a noise that a heart can make if turbulence is created. Where and when the turbulence occurs; to what degree and for how long; and what effect this has on a patient decides if the patient is really sick or not.
So if a fever or cough went away, would it be correct to say that you have a fever or cough "in remission?" No. Neither would it be for a murmur either.
There are instances of murmurs
created simply by increased heart rates, or when the heart is attempting to pump against a higher pressure. In other words, there are no anatomical defects (such as a hole in the septum, or valvular abnormality) but is simply extra flow noise generated by the increased amount of blood flow. Slowing down the heart rate and maintaining good blood pressure control may resolve these kinds of high output, aka "functional" or "physiologic" murmurs.