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33rd International Congress on Electrocardiology

International Society of Electrocardiology

Alteration Of Negative Sequence Voltages In Atria By The Amplatzer Occluder In Patients With Atrial Septal Defect

Meeting Abstract

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  • corresponding author presenting/speaker W. Carson - National Taiwan University, Taipei, Taiwan
  • J.-K. Wang - National Taiwan University, Taipei, Taiwan
  • Y.-Z. Tseng - National Taiwan University, Taipei, Taiwan

33rd International Congress on Electrocardiology. Cologne, 28.06.-01.07.2006. Düsseldorf, Köln: German Medical Science; 2007. Doc06ice137

The electronic version of this article is the complete one and can be found online at:

Published: February 8, 2007

© 2007 Carson et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Question: Study (IJBEM 2003) of the P-loop found that abnormal inscription direction of the P-loop had partial negative sequence (PNS) or complete negative sequence (CNS) type similar to the Physics problem of generators. Can these abnormalities of the P-loop be found in patients with atrial septal defect (ASD), and can they be altered by the Amplatzer occluder (AO)?

Method used: A total of 28 patients with secundum ASD received transcatheter occlusion of the ASD. They had pre and post-operation Frank vectorcardiographic (VCG) and ECG examinations.

Results: The pre-VCG test of the P-loop showed that the Left Sagittal plane had eight PNS and one CNS (32%). The post-VCG test revealed that half of the PNS and one CNS type returned to normal rotation. However, five normal anticlockwise p-loops changed to PNS type. The pre-VCG test showed that the Frontal plane had nine PNS and four CNS (46%). The post-VCG test revealed that three PNS and one CNS type returned to normal. Three PNS downgraded to CNS type. However, three normal P-loops deteriorated into PNS type, and two into CNS type.

Conclusion: Therefore, in patho-electro-physics-physiology, AO can alter negative sequence voltages from ASD, but AO itself can also contribute to iatrogenic negative sequence voltages in the atria.