Detection of repolarization abnormalities in patients with cardiomyopathy using current vector mapping technique on magnetocardiogram

Junko Shiono, Hitoshi Horigome, Akira Matsui, Yasushi Terada, Tsuyoshi Miyashita, Keiji Tsukada

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Objectives: We have previously developed current vector maps of tangential components on the magnetocardiogram (MCG) to obtain cardiac current distribution images. The present study was conducted to detect repolarization abnormalities in patients with cardiomyopathy using the current vector map. Subjects and methods: Thirteen patients with cardiomyopathy (nine males and four females aged 7-16 years, mean, 11.5 ± 3.1 years, ±SD), and 15 age- and sex-matched normal subjects were studied. Normal components (Bz) of MCG were measured at rest with a multi-channel superconducting quantum interface device (SQUID) system, and differentiated in the tangential direction to obtain current vector maps. Homogeneity of current in the heart during repolarization was investigated. The direction of the maximum current vector was also calculated in each case. Results: In all normal subjects, the current vector consistently showed a left downward direction on the frontal chest plane during the repolarization process. On the other hand, 8 out of 13 patients with cardiomyopathy showed different patterns; four of these patients showed multi-dipoles, and the other four showed a shift in the current vector direction. One of the eight cases showed no abnormality on electrocardiogram (ECG). Conclusions: Repolarization process in patients with cardiomyopathy was apparently different from those in normal subjects on the current vector map. It was easy to visualize the repolarization process as a projection to the frontal plane, including regional abnormalities, by the current vector maps, which might be more useful for early detection of repolarization abnormalities than ECG.

Original languageEnglish
Pages (from-to)163-170
Number of pages8
JournalInternational Journal of Cardiovascular Imaging
Volume19
Issue number2
DOIs
Publication statusPublished - Apr 1 2003
Externally publishedYes

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Keywords

  • Cardiomyopathy
  • Current vector map
  • Magnetocardiogram
  • Ventricular repolarization abnormalities

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine

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