The heart is our most important – and perhaps most mysterious – organ.

Having witnessed the extraordinary complexity and unpredictability of human hearts in the operating theatre – each one individual in its make-up, like a fingerprint – heart surgeon Reinhard Friedl examines closely the latest findings in neurocardiology and psychocardiology, and uses riveting personal stories to illustrate the complex relationship between the heart, the brain and the psyche.

Here are five interesting facts we learnt from The Beat of Life:

1. Every day the human heart pumps 9000 litres of blood and beats around 100,000 times.
2. On your seventy-fifth birthday, your heart will have beaten about three billion times.
3. The heart is the first organ to develop, long before the brain and the lungs.
4. The human heart has not changed since Homo sapiens emerged some 300,000 years ago.
5. Across cultures, the heart is a symbol of love, compassion, joy, courage, strength and truth.

The Beat of Life is out on Tuesday 2 February.