Source of human heartbeat revealed in 3D

Scientists have revealed the source of human heartbeat in unprecedented detail, an advance that may help surgeons repair hearts without damaging precious tissue.
Researchers, including those from University of Manchester in the UK, developed a way of producing three dimensional (3D) data to show the cardiac conduction system - the special cells that enable our hearts to beat.
"The 3D data makes it much easier to understand the complex relationships between the cardiac conduction system and the rest of the heart," said Jonathan Jarvis from Liverpool John Moores University in the UK.
Soaking post-mortem samples in a solution of iodine means soft tissue such as the heart can absorb X-rays and become visible, researchers said.

With modern X ray scanners, scientists can make detailed 3D images. In the best images, they can even see the boundaries between single heart cells, and detect in which direction they are arranged.
Within the heart, there is a special network called the cardiac conduction system that generates and distributes a wave of electrical activity stimulating the heart muscle to contract, researchers said.

This system makes sure that the various parts of the heart contract regularly and in a coordinated way, a bit like a team of rowers in a boat race.
If the system is damaged, and one part of the heart contracts out of time with the rest, then the heart does not pump so efficiently, they said.

The new data gives a much more accurate framework than previously available for computer models of the heartbeat and should improve the ability to make sense of troublesome heart rhythms like atrial fibrillation that affects 1.4 million people in the UK, researchers said.
The data reveals exactly where the cardiac conduction system is in a normal heart. For example, it shows just how close it runs to the aortic valve.
"We also use the data to make 3D printed models that are really useful in our discussions with heart doctors, other researchers and patients with heart problems," Jarvis said.
New strategies to repair or replace the aortic valve must therefore make sure that they do not damage or compress this precious tissue, researchers said.

"In future work we will be able to see where the cardiac conduction system runs in hearts that have not formed properly. This will help the surgeons who repair such hearts to design operations that have the least risk of damaging the cardiac conduction system," Jarvis said.
The study was published in the journal Scientific Reports.