The Cleveland Clinic is a Cleveland institution, with basically a whole neighborhood to themselves in the city and outposts in every suburb and town in Northeast Ohio. But it's not just their modern innovations that have been world-renowned. Back in the 1950s, 60s and 70s, the Clinic and other hospitals and research centers around town were on the cutting edge of cardiac research. These photos capture some of those advancements.

All photos via the Cleveland Memory Project.