New clues to a 500-year old mystery about the human heart

Scientists show that muscular structures first described by Leonardo da Vinci are essential for heart function

The human heart is the first functional organ to develop and starts beating spontaneously only four weeks after conception.

Early in development, the heart grows an intricate network of muscle fibers – called trabeculae – that form geometric patterns on the heart’s inner surface. These are thought to play a role in enriching oxygen with the development of the baby’s heart. But their function in adults has remained an unsolved riddle since the 16th century.

Leonardo da Vinci was the first to draw these intricate muscles inside the heart 500 years ago. He speculated that they warm the blood as it flows through the heart, but their true importance has not been recognized until now.

“Leonardo da Vinci sketched trabeculae and their snowflake-like fractal patterns in the 16th century and it’s only now that we’re beginning to understand how important they are to human health,” says Declan O’Regan, Clinical Scientist and Consultant Radiologist at the MRC London Institute of Medical Sciences.

Researchers at Cambridge have investigated the function of the muscle fibers of the heart. The study, published in the journal Nature, sheds light on questions asked by Leonardo da Vinci and shows how the shape of these muscles impacts heart performance and heart failure.

To understand the roles and development of trabeculae, an international team of researchers used artificial intelligence to analyze 25 000 magnetic resonance imaging (MRI) scans of the heart in addition to heart morphology and genetic data. The study reveals how trabeculae work and develop, and how their shape can influence human heart disease.

The research, which UK Biobank has made its data openly available. suggests that the rough surface of the heart ventricles allows blood to flow more efficiently during each heartbeat, just like the dimples on a golf ball reduce air resistance and help the ball travel further.

The study also highlights six regions in human DNA that affect how the fractal patterns in these muscle fibers develop. The researchers also found that two of these regions also regulate branching of nerve cells, suggesting a similar system may be at work in the developing brain.

Read more about: HEART, Leonardo da Vinci