A true genius of the Renaissance, Leonardo da Vinci was recognized for his genius in anatomy, architecture, cartography, design, engineering, math, physiology, science, and sculpture.
Leonardo’s drawings and writings on the heart’s anatomy and function have proven to be remarkably accurate. Long before William Harvey described blood circulation in 1616, Leonardo deciphered cardiac function using the heart’s anatomy.
A new study by the Imperial College London has suggested that structures first sketched by artist Leonardo da Vinci are crucial in understanding how the heart works.
The new study is the first to show how a complex mesh of muscle fibers that line the heart’s inner surface assumes an essential job in its function by expanding the proficiency of blood flow through the organ.
The study could help determine those most at risk of heart failure, one of the leading causes of death worldwide, and inform research into new treatments.
Dr. Declan O’Regan from the MRC London Institute of Medical Sciences, Director for Imaging Research at Imperial College Healthcare NHS Trust and lead author of the study, said: “Leonardo da Vinci sketched these intricate muscles inside the heart half a millennium ago, and it is only now that we are beginning to understand how important they are to human health.”
“Da Vinci was also intrigued by the link between maths and nature, so it’s fitting that we found that fractal patterns in the heart are so important for its function. This work offers an exciting new direction for understanding the heart and shows the potential for bringing together ideas in maths and biology to medical research.”
Using AI, scientists analyzed 25,000 MRI scans of patients’ hearts from the UK Biobank study (from 2014-2020). An additional 1,129 strong volunteer hearts were scanned at Imperial College Healthcare NHS Trust and 510 patients with dilated cardiomyopathy at Royal Brompton Hospital. The scans showed the intricate structure of these muscle fiber, which are called trabeculae.
Scientists further explored the role of trabeculae in heart function. They do=emonstrate that the trabeculae muscles form a repeating geometric pattern known as a fractal, seen in other structures from trees to snowflakes.
Da Vinci was the first to sketch these muscles in the 16th Century, speculating at the time that they warm the blood as it flows through the heart; however, their true importance has not been recognized until now.
Scientists found how this network of muscle fibers that cover the internal surface of the heart’s chambers is critical to the performance of the heart. These fibers allow blood to flow more efficiently during each heartbeat, similar to how dimples on a golf ball help it travel further through the air.
Six regions in DNA affect how the fractal patterns in these muscle fibers develop. Scientists also found that two of these genes also regulate branching of nerve cells, suggesting a similar mechanism at work in the developing brain and the heart.
Scientists found that trabeculae may influence the risk of heart disease. Using genetics to analyze data from 50,000 patients found that different fractal patterns in these muscles affected the risk of developing heart failure. It is hoped this will enable future research on the disease, which affects around 920,000 people in the UK.
Dr. O’Regan said: “This network of muscles lies between fast-flowing blood inside the heart and the contracting heart muscle. The next steps for our research are to understand how these fibers affect the ‘aerodynamics’ of blood flow in the heart and how this might inform research into new treatments for heart disease.”
“We also found that these fibers influence how fast electrical impulses travel through the heart – so they may be important for more than one aspect of how the heart works.”
Dr. Hannah Meyer, who collaborated with Dr. O’Regan on the Cold Spring Harbor Laboratory study in the US, added: “Our work significantly advanced our understanding of the importance of myocardial trabeculae. But perhaps even more importantly, we also showed the value of a truly multi-disciplinary team of researchers.”
“Only the combination of quantitative genetics, clinical research, and bioengineering led us to discover the unexpected role of myocardial trabeculae in the adult heart’s function.”
Ewan Birney, Deputy Director-General of the Laboratory “EMBL’s European Bioinformatics Institute (EMBL-EBI),” who also collaborated on the study, said: “Our findings answer ancient questions in basic human biology. As large-scale genetic analyses and artificial intelligence progress, we’re rebooting our understanding of physiology to an unprecedented scale.”
Scientists will conduct further study on these muscles inside the heart, hoping this could lead to new directions for understanding how common heart diseases develop and how they are treated.
- Meyer, H.V., Dawes, T.J.W., Serrani, M. et al. Genetic and functional insights into the heart’s fractal structure. Nature, (2020). DOI: 10.1038/s41586-020-2635-8