UM Cardiovascular Center Performs 500th Heart Device ImplantMath and physics teacher Darol Straub, 65, of Ann Arbor, helped high school and community college students make sense of the laws of motion, but by spring of this year his heart struggled to pump. On May 7 he was implanted with a left ventricular assist device that pumps blood in a way his failing heart no longer could. It was a milestone for Straub and the UM Cardiovascular Center, which marked its 500th heart implant.