title: Cardiac arrhythmias imprint specific signatures on Lorenz plots.
abstract: BACKGROUND
  Despite the growing number of studies using Lorenz (Poincaré) plots (LPs) for the analysis of heart rate variability (HRV), a possible correlation between the underlying ECG waveforms and the RR scatter plots has never been systematically studied. We report a comprehensive investigation of distinct Lorenz plot patterns (LPPs) encountered in the context of major cardiac tachyarrhythmias as assessed by 24-hour Holter monitoring and detail the mechanisms underlying the specific LPPs.
  
  
  METHODS
  The 24-hour ambulatory electrocardiograms (AECGs) of 2700 patients with atrial and/or ventricular tachyarrhythmias and the AECGs of 200 controls with pure sinus rhythm were analyzed using an Elatec arrhythmia analyzing system (Elamedical, Paris 1996). This system allows for the generation of two-dimensional LPs and the exploration of the underlying ECG waveforms. Each LPP obtained was categorized according to its shape and basic geometric parameters. In accordance with the most characteristic LPP feature, the LPPs were grouped into the following distinct classes: 1) comet shape; 2) torpedo shape; 3) H-Fan shape; 4) SZ-Fan shape; 5) double side lobe pattern type A (DSLP-A); 6) double side lobe pattern type B (DSL-B); 7) triple side lobe pattern type A (TSLP-A); 8) triple side lobe pattern type B (TSLP-B);9 island pattern type A (IP-A); 10) island pattern type B (IP-B).
  
  
  RESULTS
  While a comet or a torpedo shape was associated with sinus rhythms, the other LPPs were specifically linked to the presence of cardiac tachyarrhythmias. Thus, a Fan shape was associated with atrial fibrillation or multifocal atrial tachycardia, whereas a DSLP indicated the presence of atrial premature beats, and a TSLP was highly specifically linked to frequent ventricular premature beats. An island pattern was exclusively associated with the presence of an atrial tachycardia or atrial flutter (sensitivity: 100%, specificity: 100%).
  
  
  CONCLUSIONS
  Major tachyarrhythmias imprint specific patterns on two-dimensional Lorenz plots generated from 24-hour Holter recordings. Thus, the Lorenz plot method has the potential to significantly improve the accuracy of arrhythmia detection and differentiation, particularly with respect to supraventricular tachyarrhythmias.
authors.affiliation: Division of Cardiology, School of Medicine, Otto-von-Guericke-University, Magdeburg, Germany. esperer@medizin.uni-magdeburg.de
authors.forename: Hans D
authors.initials: HD
authors.lastname: Esperer
authors.forename: Chris
authors.initials: C
authors.lastname: Esperer
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cohen
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D015716:Electrocardiography, Ambulatory / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted