The doc listened to her heart with a stethascope. Gooby is actually small so that is why I think she is Maine coon mix. I bought her some CatSip milk which she gives a few laps before running off. My husband has also put some wet food (Friskies) and mixed it with some CatSip and chickenbroth, puts in a blender and liquifies it and puts it out for her and she does the same thing. Other than that she is perfectly healthy. Personally I don't believe her heart is weak - just small, as she runs all over and actually jumps from the floor onto the countertops (around 3.5 - 4 ft). I'm thinking my vet is not very experienced with this problem.