title: [Abnormal Q wave in the right precordial leads unmasked during right bundle branch block in a patient with anteroseptal myocardial infarction: a case report].
abstract: Electrocardiography in a 77-year-old woman showed small R waves in leads V1-V3 3 hours after the onset of acute anteroseptal myocardial infarction. Abnormal Q waves appeared in leads V1-V3 only during intermittent right bundle branch block. The normal septal force disappeared after transmural septal infarction and a small force of right ventricle origin became apparent as a small R wave in V1. Right bundle branch block delayed activation of right ventricle, and thereby deleted the initial R wave and unmasked the Q wave of the septal infarction. Appearance of a Q wave in leads V1-V3 with right bundle branch block should not be assumed to reflect the extension of myocardial infarction.
authors.affiliation: Second Department of Internal Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University.
authors.forename: A
authors.initials: A
authors.lastname: Matsuki
authors.forename: K
authors.initials: K
authors.lastname: Mizumaki
authors.forename: A
authors.initials: A
authors.lastname: Fujiki
authors.forename: H
authors.initials: H
authors.lastname: Asanoi
authors.forename: T
authors.initials: T
authors.lastname: Nozawa
authors.forename: T
authors.initials: T
authors.lastname: Hirai
authors.forename: T
authors.initials: T
authors.lastname: Kameyama
authors.forename: H
authors.initials: H
authors.lastname: Inoue
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications* / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology*