gms | German Medical Science

33rd International Congress on Electrocardiology

International Society of Electrocardiology

Increasing of nocturnal LAS40uv in Brugada syndrome relevant the arrhythmogenic substrate

Meeting Abstract

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  • corresponding author presenting/speaker K. Yoshioka - Tokai University, Isehara, Japan
  • M. Amino - Tokai University, Isehara, Japan
  • T. Tanabe - Tokai University, Isehara, Japan

33rd International Congress on Electrocardiology. Cologne, 28.06.-01.07.2006. Düsseldorf, Köln: German Medical Science; 2007. Doc06ice098

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

Published: February 8, 2007

© 2007 Yoshioka 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.



We have previously reported that a fluctuation of a late potential (LP-F) could be evaluated by Holter ECG and VF vulnerability was involved in a degree of LP-F in Brudaga syndrome (BS). VF is more induced in the large fluctuation group (LFG) than small fluctuation group (SFG), however a factor that produces a LP-F is not known. We tested the hypothesis that either RMS40ms or LAS40uv as an index of LP parameters was more relevant a substrate of LP-F in BS than F-QRSD. In addition, we studied the correlation with LP-F and heart rate viability (HRV) at night.

Methods: 18 BS patients (mean age 56+12) underwent a high resolution LP-Holter recording (2.5uv, 1000Hz, Ela Co Ltd) at night and during pildicainaide infusion test (Pil-T). Dominant 200 QRS waves were added every 15 min under 0.6 or less of the noise level, and we estimated each fluctuation rage of F-QRSD, RMS40ms and LAS40uv with HRV.

Result: Degree of LAS40uv fluctuation at night was largest (52%increasing) in LP 3 parameters, whereas increasing rates of F-QRSD, RMS40ms and LAS40uv were almost at the same level during Pil-T (Table 1). Correlation with RMS40ms and high frequency component (HF) at night was highest, and that of LAS40uv with HF was also showed a significance (Table 2), while low frequency component/HF (LF/HF) had a no relation with LP 3 parameters.

Conclusions: We conclude that F-QRSD and RMS40ms may not reflect a substrate of LP fluctuation but the existence of LP itself because these 2 parameters showed large increasing only during Pil-T, however LAS40uv also showed a large change at night and thus it may be involved in the substrate of LP fluctuation. One of the reasons of the variability of RMS40ms and LAS40uv may be affected by autonomic activity mainly because of a vagal tone.

Table 1: Fluctuation degree of LP 3 parameters (%)

At night: F-QRSD-28%, RMS40ms-34%, LAS40u-52%

During Pil-T: F-QRSD-47%, RMS40ms-73%, LAS40u-63%

Table 2: Coefficient of correlation with LP 3parameters and HRV at night

HF: F-QRSD-R=0.43, RMS40ms-R=0.48*, LAS40u-R=0.52*

LF/HF: F-QRSD-R=0.35, RMS40ms-R=0.41, LAS40u-R=0.39

(HF: high frequency component, LF: low frequency component, R: coefficient relative index between each LP parameter and HF, LH/HF, *p<0.05.)