This handbook - which has been formally adopted by the Royal Brompton and Harefield NHS Trust - is a homunculus of cardiology knowledge, based on the experience of the authors with the sole aim of helping the reader make a decision when faced with the daily challenges of cardiology. Living in an age where access to the latest trial data is immediate, for many people lack of knowledge is not the problem, instead it is inadequate experience that holds them back from making a decision based on that knowledge. The Editor calls this 'evidence based paralysis'- sometimes you don't want to know what a group of experts decided in the latest trial but simply want to know what to do next. Obviously there is no substitute for experience but to help you along the way this book will help you 'get off the fence' and indicate what the authors have done in similar situations.