The importance of the developmental approach for experimental and clinical cardiology is indisputable. Clinical-epidemiological studies have clearly shown that the risk factors of serious cardiovascular diseases, such as atherosclerosis and ischemic heart disease, are already present during the early phases of ontogenetic development. Furthermore, congenital cardiovascular malformations remain the single largest cause of infant mortality from congenital defects in industrial countries. It is therefore not surprising that the interest of theoretical and clinical cardiologists in the developmental approach keeps increasing. Advances in molecular biology accelerated this trend substantially. This book is based on contributions presented at the international symposium The Developing Heart in Prague in May 2000. It should stimulate the curiosity of cardiovascular scientists in gaining insight into the mechanisms of normal and pathological development.