Hearts

The heart seems like a simple device. It is two pumps connected together into one organ. One pump pushes blood through the lungs to oxygenate, and the other pump pushes the resulting oxygenated blood throughout the body.

Heart diseases are the most common cause of death, so replacing the biological heart with a more robust artificial heart that is not subject to diseases should help reduce these deaths.

The first early artificial heart was created in 1937 by Vladimir Demikhov. It was a large device that did not fit in the body. When tested on a dog, the dog lived for more than 5 hours afterwards. Along with the artificial heart, Vladimir is also known for the first lung transplant, the first liver transplant, a number of firsts in heart transplants, and most controversially, the first head transplant, transplanting the head of one dog onto another dog's body in the 1950s.

In 1949, an artificial heart was created by two doctors, William Sewell and William Glenn, out of toys, and was used to bypass the circulation of a dog for more than an hour.

The first human use of an artificial heart wasn't until 1952, when one was used temporarily during a surgery to take over circulation in a patient, Henry Opitek, while his own heart was being repaired. Henry survived another 30 years after the operation.

The first fully implantable total artificial heart (TAH), designed by Robert Jarvik, was installed by Willem Kolff in a dog in 1957. The design was arguably based on a patented design by Paul Winchell (with assistance from Henry Heimlich, who invented the Heimlich Manouvre). The dog lived for 90 minutes.

The first permanent installation was a partial heart in 1966, when Adrian Kantrowitz installed a left ventricular assist device.

Willem Kolff continued working on his TAH, with increasing success. A calf lived for 30 days in 1973, a bull for 90 days in 1975, a calf for 184 days in 1976, a calf for 268 days in 1981.

More than 200 people helped to work on these projects, with each version of the heart being named after the project managers.

In 1981, William DeVries got permission from the FDA to install the first permanent TAH. A Jarvik 7 (from Willem Kolff's work, named after Robert Jarvik) was installed in Barney Clark, a Seattle dentist. He lived for 112 days, but was so distraught by the side-effects of the device that he asked a few times to be allowed to die.

Jarvik 7 total artificial heart

The second attempt was more successful, but not by much. In 1984, William Schroeder was given a Jarvik 7 heart. After only 18 days, though, he suffered the first of a series of strokes, which would eventually leave him in a vegetative state. He survived 620 days after the operation, though, making this arguably a success story.

The Jarvik 7 was no longer used as a permanent prosthetic after this, instead rebranding as the SynCardia TAH, which is used these days to take over circulation in the time it takes to complete a more permanent transplant operation. The longest anyone has used a SynCardia TAH while awaiting transplant was nearly 4 years, until the patient finally received a transplant.

Even now in 2017, no permanent totally internal artificial hearts are widely available yet, as the technology has yet to advance sufficiently to allow for long battery and mechanical life.

For now, the safest option is to go for a transplant instead of an artificial heart.