gms | German Medical Science

33rd International Congress on Electrocardiology

International Society of Electrocardiology

Alteration Of Negative Sequence Voltages In The Ventricular Repolarization By Temporary Artificial Pacemakers In Patients With Bradycardia

Meeting Abstract

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  • corresponding author presenting/speaker W. Carson - National Taiwan University, Taipei, Taiwan

33rd International Congress on Electrocardiology. Cologne, 28.06.-01.07.2006. Düsseldorf, Köln: German Medical Science; 2007. Doc06ice095

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

Published: February 8, 2007

© 2007 Carson.
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 (Am J Emerg Med 2003)of patients with acute aortic dissection (AAD) has found that abnormal sense of inscription direction (ASID) and L/W ratio of the T-loop in the emergency vectorcardiogram, are at high risk of post-operationally unexpected ventricular tachyarrhythmia (UVT). A further study (IJBEM 2003) of the P-loop found that the ASID had partial negative sequence (PNS) or complete negative sequence (CNS) type similar to the Physics problem of generators. Can these abnormalities of the T-loop be found in patients with acute bradycardia, and can they be altered by temporary artificial pacemakers (TAP)? Method Used. A total of 16 patients with bradycardia received a TAP in an ICU. They had pacing off and pacing on Frank vectorcardiographic (VCG) and ECG examinations.

Results: The TAP off VCG test of the T-loop showed that the Frontal plane had five PNS and two CNS (44%). The TAP on VCG test revealed that four of the PNS returned to normal rotation. However, three normal anticlockwise T-loops changed to CNS type and one PNS worsened into CNS pattern. The TAP off VCG test showed that the Left Sagittal plane had two PNS and six CNS (50%). The TAP on VCG test revealed that one PNS and two CNS type returned to normal, and the other CNS improved to PNS type. However, one normal pattern downgraded to PNS type and three downgraded further to CNS type. The TAP off VCG examination revealed that the Horizontal plane had one PNS and five CNS (38%). The TAP on VCG record showed two CNS types returned to normal and one improved to PNS. However, two normal patterns downgraded to CNS type and one from PNS into CNS type.

Conclusion: Therefore, in patho-electro-physics-physiology, TAP can alter negative sequence voltages of the T-loops in patients with bradycardia, but TAP itself can also contribute to iatrogenic negative sequence voltages in the heart.