Pacemaker

On October 8, 1958, surgeon Åke Senning implanted a small disc-shaped device into the chest of Arne Larsson, a 43-year-old Swedish engineer whose heart stopped beating as many as 30 times a day. His wife Else-Marie had been resuscitating him with chest blows each time—an exhausting and terrifying routine that could not continue. The device, designed by physician-turned-engineer Rune Elmqvist, was molded in a plastic shoe-polish container with Araldite epoxy resin. It lasted three hours before failing and was replaced by the only existing backup, which worked for six weeks. Despite this unpromising start, Larsson would live another 43 years, outliving both his surgeon and his engineer, and requiring 22 different pulse generators before dying at age 86 of an unrelated illness.

The adjacent possible for the implantable pacemaker required converging advances in electronics, materials, and cardiac physiology. External pacemakers had existed since 1926, when Mark Lidwell in Australia demonstrated that electrical stimulation could restart a stopped heart. Paul Zoll's 1952 external pacemaker kept patients alive but required painful chest-wall electrodes and bulky equipment that confined patients to hospital beds. What Elmqvist and Senning achieved was miniaturization: cramming the pacing electronics into a device small enough to implant.

The silicon transistor, commercialized in the mid-1950s, made miniaturization possible. Elmqvist's pacemaker used silicon transistors to generate pulses of 2 volts amplitude at 70-80 beats per minute. The device measured 55 mm in diameter and 16 mm thick. Two rechargeable nickel-cadmium batteries provided power, requiring inductive recharging through the skin every week via a 12-hour charging session. The engineering challenges were immense: creating a hermetic seal that would not leak body fluids, leads that would not break inside the body, and electronics that could operate reliably for years without maintenance.

Why Sweden? Karolinska University Hospital had both the cardiac surgical expertise (Senning was a pioneering heart surgeon) and access to Elmqvist, who had trained as a physician before moving into engineering at Elema-Schönander. The desperation of the Larsson case—pushed forward by Else-Marie's insistence that something must be done—motivated the team to move from animal experiments to human implantation faster than might otherwise have occurred.

The convergent development of pacemakers unfolded rapidly across multiple countries. Wilson Greatbatch in the United States developed an implantable pacemaker independently in 1958, and his lithium-iodide battery design (1970s) would eventually replace rechargeable batteries. Earl Bakken's Medtronic, founded in a Minnesota garage, would become the dominant pacemaker manufacturer. By the 1960s, pacemakers had evolved from experimental curiosities to standard cardiac therapy.

Elmqvist himself remained skeptical. After the first implantation, he viewed cardiac pacemakers as 'a technological curiosity, more or less.' He was wrong. Today, over one million pacemakers are implanted annually worldwide. The devices have evolved to include dual-chamber pacing, rate-responsive algorithms, MRI compatibility, and wireless monitoring—but they remain recognizable descendants of the disc that Elmqvist molded in a shoe-polish container in 1958.