After 500 Years, a Mathematical Principle Has Unlocked Leonardo Da Vinci's Human Heart Mystery

Researchers finally understand the function of a heart feature first described by Leonardo da Vinci 500 years ago. To find the answer, scientists used fractal theory, MRIs, and a lot of computational elbow grease to shed light on muscular structures called trabeculae. Their study, published in Nature, found that this branching, lacy muscle layer plays a part in identifying a patient’s risk of heart disease.

- By Caroline Delbert

The trabeculae cover the inner surfaces of the heart and were thought to be a remnant of embryonic development. Leonardo da Vinci drew detailed pictures of the fine, snowflake-like trabeculae after dissecting and examining a heart. ‘He was quite intrigued by them and he thought they warmed the blood,’ says Declan O’Regan, PhD, a clinical scientist and radiologist at Imperial College London in the UK, who worked on the study.

The broad international research team tapped a special resource: the UK Biobank, a database of more than 500 000 adult volunteers (O’Regan and his team analysed a subset of 18 000 people) who have had genetic testing, MRI scans, and other procedures in order to make their data available to researchers around the world.

The study of trabeculae might date back centuries, and scientists have looked at the recurring, web-like, and unusual pattern of muscle fibres for almost 450 years. But that hasn’t been enough to understand why the muscle is there, what it’s doing, or how it develops.