Scatter Diagram Analysis: A New Technique for Discriminating Ventricular Tachyarrhythmias

R. D. Throne, John Robert Windle, Arthur R Easley Jr, B. Olshansky, D. Wilber

Research output: Contribution to journalArticle

10 Scopus citations


With the increasing flexibility allowed by implantable cardioverter defibrillators that use tiered therapy, it is important to match the therapy with the arrhythmia. In this article we present scatter diagram analysis, a new computationally efficient two‐channel algorithm for distinguishing monomorphic ventricular tachycardia (VT) from polymorphic ventricular tachycardia and ventricular fibrillation (VF). Scatter diagram analysis plots the amplitude from one channel versus the amplitude from another channel on a graph with a 15 × 15 grid. The fraction (percentage) of the 225 grid blocks occupied by at least one sample point is then determined. We found that monomorphic VT traces nearly the same path in space and occupies a smaller percentage of the graph than a nonregular rhythm such as polymorphic VT or VF. Scatter diagram analysis was tested on 27 patients undergoing intraoperative implantable cardioverter defibrillator testing. Passages of 4.096 seconds were obtained from rate (bipolar epicardial) and morphology (patch) leads, and digitized at 125 Hz. Scatter diagram analysis distinguished 13 episodes of monomorphic VT (28.6%± 4.0%) from 27 episodes of polymorphic VT or VE (48.0%± 8.2%) with P < 0.0005. There was overlap in only one monomorphic VT episode and one polymorphic VT or VF episode.

Original languageEnglish (US)
Pages (from-to)1267-1275
Number of pages9
JournalPacing and Clinical Electrophysiology
Issue number7
Publication statusPublished - Jul 1994



  • amplitude distribution analysis
  • implantable cardioverter defibrillator
  • magnitude squared coherence
  • scatter diagram analysis
  • ventricular electrogram morphology
  • ventricular tachycardia

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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