Third-degree atrioventricular block by endurance training?

By means of a follow-up of 2 cases the problems of the third-degree atrioventricular block are discussed. The 2 cases reports demonstrate the hypervagotonia with passing third-degree atrioventricular block in athletes without cardiac disease. The 2 cases make visible, that extreme thinking of security with prophylactic stopping physical training may cause harms regarding quality of life. It only is necessaire to wait and see. Particularly in veteran endurance athletes an indication for reducing training or for pacemaker implantation may occur.