Skip to main content
padlock icon - secure page this page is secure

Testing of a New T-Wave Subtraction Algorithm as an Aid to Localizing Ectopic Atrial Beats

Buy Article:

$52.00 + tax (Refund Policy)

Background: Identifying the timing and morphology of an ectopic P wave from the surface electrogram can aid in the diagnosis and localization of atrial arrhythmias. Given the relatively short coupling interval of atrial ectopic beats, the P wave is often obscured by the larger amplitude QRS-T wave complex. A method to uncover such “buried” P waves using a standard 12-lead surface ECG would be clinically useful and could potentially be a noninvasive guide to catheter ablation of focal atrial tachycardia.

Methods: We developed an automated computerized program (BARD DUO LAB SYSTEM™) designed to subtract the QRS-T wave complex from the surface electrogram and uncover a previously obscured P wave. The purpose of the present study was to validate this program. The surface ECG from 21 patients undergoing atrial pacing during electrophysiologic study (group I) and 10 patients with atrial tachycardia (group II) were analyzed and the derived P-wave morphology assessed using correlation waveform analysis (CWA) and visual grading by three reviewers.

Results: The algorithm successfully uncovered the P wave in each surface ECG. For the 21 patients in group I, average CWA comparing the derived P wave with the previous paced P wave was 83%. Average CWA for group II was 82%. Visual grading of the match between derived P waves and paced P waves revealed a 21/21 match in group I patients and a 12/12 match in 9/10 of group II patients.

Conclusions: An ectopic atrial P wave obscured by a coincident QRS-T wave complex can be accurately uncovered using this new algorithm. Addition of this technique to existing methods may improve the diagnosis of atrial arrhythmias and aid in the localization and ablation of ectopic atrial foci.

A.N.E. 2003;8(1):55–59
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: P wave; QRS-T subtraction; atrial arrhythmia; catheter ablation; mapping

Document Type: Research Article

Affiliations: 1: Tufts University School of Medicine, New England Medical Center Hospitals, Boston, MA, USA 2: University of Oklahoma, Tulsa, OK, USA 3: Bard Electrophysiology, Lowell, MA, USA

Publication date: January 1, 2003

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more