[Eden Prairie Sun Current, November 13, 2015] In fourth grade, Rob Johnston was told by doctors that his heart had a murmur. As time progressed, he thought he outgrew it. However, at age 35, Johnston was diagnosed with mitral valve regurgitation during a routine physical. “It was a pretty nerve-wracking experience,” said Johnston, an Eden Prairie police officer. He then received minimally invasive mitral valve surgery in April at the Minneapolis Heart Institute at Abbott Northwestern Hospital.