title: Transient focal septal block.
abstract: A 65-year-old woman with an acute myocardial infarction, as judged by serial enzyme changes, developed transitory Q waves in leads V2 to V4 and leads 2, 3, and aVF during an attack of pain in the chest. 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-branch system. This defect could underlie 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.
mesh_terms: D000368:Aged; D000787:Angina Pectoris; D002036:Bundle of His / Q000503:physiopathology*; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D013997:Time Factors