Silent danger Coronary heart disease: When the heart suddenly stops beating. “Sport alone does not protect the heart,” warns Hamburg cardiologist Prof.

Thomas Meinertz. ‘If you have a heart attack, you should call the emergency services (112) immediately. If cardiac arrest occurs, cardiac massage should be started immediately and continued until the doctor arrives," says Prof. Heribert Schunkert, director of the clinic for adult cardiology at the German Heart Center Munich.