Werner Forssmann inserted in 1929 a urethral catheter from a vein in his own arm into the right cardiac chamber, demonstrating that human intracardiac access was technically possible and clinically tolerable. The initial reaction was condemnation and professional ridicule: he was dismissed from his post and abandoned cardiovascular research. Decades later, the cardiac catheterization he pioneered became the basis of all diagnostic and interventional cardiology. Nobel Prize in Medicine 1956.