Grade 4 heart murmur silent while under anesthetic

Hi would like some advice if anyone can help. In April this year I recused a black male cat called Chester he was about 2 from the local Cat rescue. Two days later after we adopted him I took him to the vet to get check over when the vet informed me he could hear a murmur. I took Chester to a specialist where they had confirm a grade 4 mumur. He had X-rays which showed no fluid but the heart was slightly enlarged his blood tests revealed it was heart failure of which the vet was surprised at as he is quite a healthy cat and no fluid on his lungs He is on heart medication, however a few weeks ago he dislocated his hip needing him to have urgent operation. I took him back today for his check up and after an X-ray it showed the op didn't work and they would need to operate again today. The operation went well however today under sedation and then general anesthetic both times the mumur had gone the vet got a second and third opinion from two other cardiologists whom agreed no sign of the murmur. On both occasions today there was no sign of a grade 4 murmur.

Can anyone explain how this possible as the vets couldn't answer this.

Thanks

It sounds very strange, esp when a heart murmer is considered a risk in terms of surgery because of the effect anaesthesia has on blood pressure.   However, I have also read that cats can present with heart murmers but that they can come and go, even when the murmer is measured at a high level.   It would be interesting to know if the murmer does return.

The good thing is that Chester has got through all this surgery well, and seems to be in good health despite the heart issues that the vets have detected.  I hope that he continues to stay in good health and that this most recent surgery has been a success. 

Was Chester given IV or SubQ fluids while sedated by chance?

Hi I'm not to sure I know they used a different method drugs as opposed to normal methods because of the mumur. Could either keep clear the mumur ?.

Thank you he's doing so well, it's amazing what he has been through and he keeps on fighting! Just so confused on where we go now in regards to his heart

Hi just called the vets it was IV

Can you take him to a cardiologist? Or is that who you are dealing with?

This is kind of strange because he was diagnosed to be in heart failure. I would definitely consider an echocardiogram (ultrasound of heart) to fully get a grasp on things. 

If I were in your position, I would seriously want to investigate this before going back to his heart meds. Those are serious meds. 

Good Luck and keep us posted!