title: Magnetocardiographic studies of ventricular repolarization in old inferior myocardial infarction.
abstract: Isomagnetic maps of 50 normal subjects (control group) and 23 patients with old inferior myocardial infarction (IMI group) were recorded in order to analyse T wave abnormalities in inferior myocardial infarction. The T wave of the magnetocardiogram (MCG) in the control group showed negative deflections in the left upper portion and positive deflections in the right lower portion, thus resulting in a T vector directed leftward and inferiorly. The T wave of the IMI group was flat or positive in the left upper portion and flat or negative in the right lower portion, suggesting a T vector directed superiorly. In addition, opposing dipoles were observed in 36.4% of the IMI group; i.e. one directed superiorly, presumably due to inferior myocardial ischaemia, and the other directed inferiorly due to normal repolarization. Localized T vector abnormalities could be detected by the MCG in some cases, in which coronary T waves of the standard electrocardiogram had returned to normal. Furthermore, multiple dipoles were more frequently observed in the isomagnetic map than in the isopotential map (5 vs. 15; P less than 0.01). These results suggest that the MCG is helpful in diagnosing myocardial ischaemia when this is not detectable on the electrocardiogram.
authors.affiliation: Second Department of Internal Medicine, School of Medicine, University of Tokushima, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nomura
authors.forename: Y
authors.initials: Y
authors.lastname: Nakaya
authors.forename: K
authors.initials: K
authors.lastname: Fujino
authors.forename: S
authors.initials: S
authors.lastname: Ishihara
authors.forename: M
authors.initials: M
authors.lastname: Katayama
authors.forename: A
authors.initials: A
authors.lastname: Takeuchi
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Hiasa
authors.forename: T
authors.initials: T
authors.lastname: Aihara
authors.forename: H
authors.initials: H
authors.lastname: Mori
mesh_terms: D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008280:Magnetics; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology