I'm very worried about my new kitten Lexie, she was diagnosed with a level 4 heart murmur on Friday. The vet is going to call me to have a cat cardiologist examine her. I just got her and her sister Lulu 2 weeks ago from a rescue group and was told that they had a clean bill of health. I'm so worried about this since I just lost my beloved cat Beanie of 11 years to a stroke. Has anyone been through this before? I've heard they can out grow this.