We all die of a broken heart… The evolution of the pacemaker

There are several used pacemakers in the HealthWorks Collection. It does sound a bit gore, because these pacemakers are “used” in the sense that they came out of people’s bodies… But they are beautiful examples of gradual minimisation and of how technology will inevitably bend to the needs of users. The evolution of the modern pacemaker is a wonderful story in the advancement of technology and in our understanding about how the heart rhythm works. The first pacemaker was implanted in a person in 1958. It didn’t last very long, though that patient lived to age 88 and had 26 pacemakers in his lifetime. Pacemakers really only entered the modern era in 1969 with the first lithium battery. In 1969, a man landed on the moon. In 1969, pacemakers had better batteries. The History of the pacemaker Pacemakers use electrical impulses to regulate the beating of the heart. They treat disorders that make the heart’s rhythm too slow, fast or irregular. Abnormal heart rhythms are called arrhythmias. It wasn’t until the late 19th century that doctors and scientists finally realized the heart worked with currents and could be revived with electricity. However, devices for artificially controlling the heart’s rate were not devised until the 20th century.

Fast-forward 50 years, to 1928, where an Australian anesthesiologist developed the first external instrument that would deliver currents via needles implanted directly into the heart. Ouch. In 1932, American physiologist Albert Hyman built the first device called an ‘artificial pacemaker’. It was powered by a hand-cranked motor. Hyman tested his pacemaker on animals, and never published any results of using his pacemaker on humans. During the 1930s artificial heart stimulation was controversial and likened to reviving the dead.

The 1931 Hyman Pacemaker, anyone ready to try it?

After the Second World War innovators such as Paul Zoll and Earl Bakken pioneered smaller pacemakers. Some of these were worn like a necklace. In 1958 the first pacemaker to be implanted was given to Arne Larsson in Sweden. The device failed after three hours. A second device lasted two days.

The first implantable pacemaker, 1958. Dr. Rune Elmqvist, the developer, was an engineer at Siemens-Elema and had previously worked as a cardiologist. For lack of time, he coated the components of the first device with epoxy resin in a shoe polish tin. Two electrodes connected to the pacemaker provided the energy to stimulate the heart. This first model had to be replaced by a new one after only a few hours.

Implanting electronic devices into the body presented problems. Electronic components were too bulky until the development of silicon transistors in 1956. Early pacemaker batteries had short, unreliable lifetimes until Wilson Greatbatch pioneered long-life lithium batteries in the 1970s. Another problem was preventing water in the body affecting the pacemaker’s electronics. This was solved by using hermetically sealed titanium cases. Pacemakers are now the size of a large coin and are implanted near the heart. It wasn’t until the mid-1960s that implantable pacemakers no longer required anesthesia or thoracotomies, working as-needed instead of continuously. The 1980s brought with them the redesign of the leads to emit steroids as a means of decreasing the tissue swelling around the implants. The advances also allowed for dual-chamber pacing — contraction of both the atria and ventricles of the heart. And in the 1990s, microprocessors were used to adapt and meet the changing needs of the patient’s heart. Today’s tech The modern pacemaker weighs less than an ounce. More recent models can respond to changes in blood temperature and breathing. With the technology boom of the 21st century, implantables are able to record and upload the heart’s data via Wi-Fi. These life-saving devices are now also able to defibrillate the heart by restoring it back to normal function. What’s next? The future of pacemakers is limitless. Modern-day batteries could mean a longer life. Improved leads could reduce the body’s chance of rejection. Pacemakers could even become the size of dimes. All that we know about the future, is that it is different from what we expect.