Artificial hearts and total replacement of your heart

Heart failure is a problem. Not just will it kill you but there was only one solution for along time. A heart transplant. If you did not get a donor heart you would die; slowly, over time and with absolute knowledge of what was happening.

Then 1982 happened and the jarvik 7 prototype came to be. Jarvik 7 was an artificial heart. An externally powered device that could pump blood around your body without a heart.

Since 1982 only 2 commercially available artificial hearts have been available. That is over approximately 45 years we have developed only 1 option than one alternative.

The reason for such a small selection is simple. Artificial hearts are complicated and come in a range of functions. Some are total artificial hearts performing the role of your natural heart in full. Others exist only to replace the role fo your ventricle, the lower heart chambers.

This is just the first problem.

Things get more complicated when you consider how the human body responds to foreign objects. It responds badly. Anything and everything foreign needs to be attacked, broken down, and removed. Doing so to the artificial heart that is keeping you alive is a good way to not be alive for much longer. Therefore all artificial hearts need to have the lowest possible risk of rejection. This is achieved by maximising bio compatibility.

At present the available models rely on pumps that pulse. This creates the simulacrum of a heart beat. However it is limited by comparison to real hearts. The heart rate, volume, and more are all largely static. It does not respond to stress, environmental cues, or other stimuli.

Those same pumps require power. In most cases some form of battery. That is both a good and bad. Good that the system remains mostly portable. Bad in that once you lose battery power your life has finite time left.

Fortunately most people do not receive an artificial heart for life. This is otherwise known as destination therapy. The destination being death. For those people their life is both defined by and dependant on the artificial heart.

For others an artificial heart is a bridge to transpolar. It keeps the patient alive long enough to receive an organ donor heart. A process that can take years and without an artificial heart may not happen before the patient dies from heart failure.

The process of implanting the prosthesis is not without notable risks. Admittedly none of the risks are different form any other kind of heart surgery. Implanting an artificial heart requires the thorax is cut open. The sternum or ribs are cut through and pulled apart. The heart is either partially dissected or completely dissected. The artificial heart is implanted and connected. Then you connect the heart to the relevant hoses, tubes and so on. The patient is closed up. Finally the tubes and hoses are connected to external devices like pumps, sensors and processors.

This sounds great and it is. The rate of death from heart failure decreases with an artificial heart. However the artificial heart is mechanical. It will fail over time. There is no current way around this. That leads to artificial hearts having a finite service life before they must be replaced. This can be as little as 1 year and as much 2 years in many cases.

The biggest issue for many is cost. An artificial heart alone can cost hundreds of thousands of dollars. That assumes that you are covered by insurance let alone the cost if you must pay for it yourself.

Emerging technology may yet help with all of these issues. Whether the devices become more bio compatible. The parts have longer working life. The power of the device is less dependant on external batteries or at least run much longer on a single charge. The devices become smaller.



Relevant links:

SynCardia Total Artificial Heart
https://www.syncardia.com/syncardia-t...

CardioWest temporary Total Artificial Heart
https://en.wikipedia.org/wiki/Artific...

Jarvik 7 artificial heart prototype
https://en.wikipedia.org/wiki/Artific...