title: Spatiotemporal properties of the fetal magnetocardiogram.
abstract: OBJECTIVE
  Our purpose was to investigate the spatiotemporal properties of the fetal magnetocardiogram.
  
  
  METHODS
  Fetal magnetocardiogram maps were measured for the first time in 20 subjects from 22 to 39 weeks' gestation. Waveform and topographic maps were used to display the data.
  
  
  RESULTS
  The maps showed spatiotemporal properties consistent with simple volume conductor theory: topography was closely related to the presentation of the fetus, Q-wave sources were dipolar and localized, the magnetic heart vector rotated extensively during the QRS complex, and close correspondence was observed between fetal and neonatal maps. Ventricular depolarization and events in the cardiac cycle could be visualized in considerable detail by means of a time series of topographic maps.
  
  
  CONCLUSIONS
  Fetal magnetocardiogram shows excellent spatiotemporal properties and is well suited for in utero studies of fetal heart activity.
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison.
authors.forename: R T
authors.initials: RT
authors.lastname: Wakai
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: C B
authors.initials: CB
authors.lastname: Martin
mesh_terms: D004562:Electrocardiography; D005260:Female; D005323:Fetal Monitoring / Q000379:methods; D006334:Heart Function Tests / Q000379:methods; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D011247:Pregnancy; D013997:Time Factors