How close are we to artificial hearts? New developments in heart health

This story comes from The Pulse, a weekly health and science podcast.

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For Sian Harding, the heart is a “miracle of construction”. The emeritus professor of cardiac pharmacology at Imperial College London continues to be amazed by this organ and its reliability that allows us to function.

“You have three billion heartbeats in your life, 100,000 a day, and you just miss 240 of them and that’s it,” she said.

In his book, “The Exquisite Machine: The New Science of the Heart,” Harding explores the science behind cardiac care and discusses the fundamentals of the heart’s physical anatomy, down to our cells.

Harding marvels that if you separate the cardiomyocytes, the individual cells of the heart muscle, “each one of them starts beating like a little heart, beautifully and over time.”

However, there are times when the heart does not do what it should and the perfect coordination of cells becomes synchronized. This is called ventricular fibrillation, which prevents the heart from pumping blood. Harding discusses the technological advances that researchers have made in response to such conditions, using devices such as the implantable cardioverter defibrillator. This device is intended for patients who have already experienced dangerous heart rhythms, or “sudden cardiac death”, and has the ability to detect irregular heart rhythms and deliver internal shocks to the heart.

Harding spoke with Pulse host Maiken Scott about some of the more advanced research into strengthening the heart using implantable devices, artificial hearts and growing hearts from stem cells.

On the challenge of developing an artificial heart

When it comes to heart replacements, whole artificial hearts (were) really quite difficult to pin down in terms of engineering. The race for a fully artificial heart began at the same time as the space race in the 1960s. And you can see what we’ve done with the space race, but whole artificial hearts are still difficult.

Partial artificial hearts, which replaced only part of the lower part of the heart, were found to be more effective. There are people who go with them. They started as a bridge to when you could receive a transplant.

About the amount of energy needed to power the heart

The problem is that this is the energy needed by the heart, ATP molecule which gives energy to the heart and everything, is actually made from glucose. The amount of energy required to keep the heart pumping for one day if ATP were not continually replenished… would be half the mass of ATP needed to do so.

It’s amazing how much kinetic energy the heart needs. So you need battery power outside your body. You can’t buy a battery small enough to hold it.

So you have to have a line through the skin. You need to carry a battery with you and of course you need to make sure it’s charged. If you think it is harmful to your phone, you certainly don’t want your heart to drop. So we’re wondering, can we do anything in terms of battery technology? There is also the idea that it will be possible to charge your phone in the same way that you place your phone on the charger without plugging it in. Maybe you can get it from outside. So you may be able to charge your device from outside your body. Actually, get a big one and lie on it.