When did the first heart pacemaker get implanted?

In 1958 surgeon Ake Senning and engineer Rune Elmqvist implanted the first fully internal pacemaker in Arne Larsson, who suffered from a dangerously slow heartbeat. The first device failed after only a few hours, and a second was fitted soon after. Early pacemakers had short battery lives and had to be replaced often, but the technology improved rapidly. Larsson went on to receive many replacement units over the years and lived into his eighties, outliving both the inventor and the surgeon. Pacemakers now help millions of people worldwide keep a steady heartbeat.