title: Delineation of premature P waves on four-dimensional electrocardiography, a new display of electrical forces by computer techniques.
abstract: This study investigated the feasibility of four-dimensional electrocardiography (4-D ECG), a new display in which the vector loop was rotated and scanned along a timed axis to overcome the shortcomings of vectorcardiography (VCG). The subjects consisted of 38 patients with premature atrial complexes and 30 controls. The orthogonal Frank electrocardiograms were rotated three-dimensionally according to the right-hand rectangular coordinate system and scanned along a timed axis. The P wave delineation score, signifying good agreement with the intraobserver and interobserver variability, was significantly higher in 4-D ECG than those in the orthogonal leads or those on the transverse and frontal projections (P < 0.001). The authors measured the premature P loop areas as viewed from 361 directions. P loop areas were best delineated when viewed from cranial directions of 42.6 +/- 34.0 degrees and from rightward directions of 11.3 +/- 30.7 degrees. Adequate cranial rotation followed by scanning along a timed axis will maximally delineate premature atrial signals and provide comprehensive visualization of electrical forces.
authors.affiliation: Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Morikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Habuchi
authors.forename: M
authors.initials: M
authors.lastname: Nishio
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Kashima
mesh_terms: D018880:Atrial Premature Complexes / Q000175:diagnosis*; D004562:Electrocardiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation