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

Every day it pumps 9000 litres of blood and beats around 100,000 times. But the heart is more than just a pump. In all major human cultures, it is seen as the source of love, sympathy, joy, courage, strength and wisdom. Why is this so?

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 went on a search for answers. He examined closely the latest findings in neurocardiology and psychocardiology, and in The Beat of Life he shares his discoveries, using riveting personal stories to illustrate the complex relationship between the heart, the brain and the psyche.