Abstract: | A 65 years old woman with an acute myocardial infarction, as it was judged by serial enzyme changes, developed transitory Q waves in V2-V4 and II, III and AVF during the attack of chest pain. These Q waves were not present 12 hours later. It is suggested that these changes represent a focal block in the septal fibers of the left bundle system. This defect could explain the transient right precordial Q waves seen in myocardial infarction or ischemia, as well as the fixed Q waves of many patients without septal infarction at autopsy. |