Question about cat food? Looking for low sodium cat with mitmur

Hi! So I have this rescue cat his name is Sir. The vet told me he has a heart murmur :( and suggested I feed him low sodium cat food...Right now he is eating wellness core food but I'm not sure of the sodium content (going to call them tomorrow)

Anyways I was wondering if anyone might have had the same thing going on and might have any suggestions?

Thanks!