Extraction of buried P waves from printed electrocardiograms

Bryant Lin, Paul J. Wang, Srijoy Mahapatra, Munther Homoud, Mark Link, N. A.Mark Estes, Amin Al-Ahmad

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Background: Morphologic identification of ectopic P-waves from surface ECGs can be challenging, particularly when the P-wave is buried in the QRST wave complex. Because ECGs are often available on paper and not digitally, we developed a method of subtracting the T-wave from the buried P-wave complex on paper ECGs. Methods: To validate our system, an atrial extrastimulus was introduced during and following the T-wave. The ECGs were scanned and then transformed from an image format to a digital format. A computer algorithm digitally subtracted a QRST with no buried P-wave from one with a buried P-wave, thus resulting in an extracted P-wave. The extracted P-waves were compared to the nonburied P-wave by determining correlation coefficients and by visual grading by two independent reviewers. Results: Visual grading comparing the buried P-wave with the exposed paced P-wave was 94%. The median correlation coefficient was 85%. Conclusions: An ectopic atrial P-wave obscured by a coincident QRST wave complex can be accurately derived from printed ECG using this PC-based system. Addition of this technique to the existing methods may aid in the localization and ablation of ectopic atrial foci.

Original languageEnglish (US)
Pages (from-to)142-145
Number of pages4
JournalAnnals of Noninvasive Electrocardiology
Issue number2
StatePublished - Apr 2005


  • Atrial premature contractions
  • Electrocardiography
  • QRST subtraction

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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