Who designed the first implantable cardiac pacemaker used in a human patient?

Rune Elmqvist designed the first implantable cardiac pacemaker used in a human patient.

Elmqvist was a Swedish physician and engineer who built the device in 1958. The pacemaker was small enough to implant inside the body and generated electrical pulses to stimulate the heart when its natural rhythm failed. It was powered by rechargeable batteries, an important limitation of the early design.

Swedish surgeon Åke Senning implanted the pacemaker in Arne Larsson at Karolinska University Hospital. The operation took place on 8 October 1958. The first device failed after only a few hours, but a replacement was implanted successfully. Larsson went on to receive many improved pacemakers during his lifetime.

A common mix-up is to credit Senning with designing the pacemaker. Senning performed the implantation, while Elmqvist created the device. Earlier external pacemakers had already been developed, including Paul Zoll’s equipment, but Elmqvist’s design was the first implanted version used clinically.