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This article is part of the supplement: 33rd International Symposium on Intensive Care and Emergency Medicine

Poster presentation

Left ventricular electromechanical dyssynchrony and mortality in cardiothoracic intensive care

G Tavazzi1*, M Bojan2, A Duncan3, A Vazir3 and S Price3

  • * Corresponding author: G Tavazzi

Author Affiliations

1 University of Pavia Foundation Policlinico San Matteo IRCCS, Pavia, Italy

2 Necker-Enfants Malades University Hospital, Paris, France

3 Royal Brompton Hospital, London, UK

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Critical Care 2013, 17(Suppl 2):P172  doi:10.1186/cc12110


The electronic version of this article is the complete one and can be found online at: http://ccforum.com/content/17/S2/P172


Published:19 March 2013

© 2013 Tavazzi et al.; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Introduction

Global left ventricular electromechanical dyssynchrony (GLVD) is uncoordinated LV contraction that reduces the extent of intrinsic energy transfer from the myocardium to the circulation leading to a reduction in peak LV pressure rise, prolonged total isovolumic time (t-IVT) and fall in stroke volume [1]. This potentially important parameter is not routinely assessed in critically ill cardiothoracic patients.

Methods

A prospective analysis of retrospectively collected data in cardiothoracic ICU patients who underwent echocardiography was performed. In addition to epidemiological factors, echo data included comprehensive assessment of LV/RV systolic and diastolic function including Doppler analysis of isovolumic contraction/ relaxation, ejection time (ET) and filling time (FT). t-IVT was calculated as (60 - (total ET + total FT)) and the Tei Index as (ICT + IRT) / ET. t-IVT >14 second/minute and Tei index >0.48 were used to define GLVD [2]. Data are shown as mean ± SD/median (interquartile range).

Results

A total of 103 patients (63.5 ± 18.4 years), 65 male (63%), APACHE II score (14.6 ± 7.4) were included. The prevalence of GLVD was high (24/103, 22%) and associated with significantly increased mortality, 7.5% vs. 25% (P = 0.02). There was no difference in requirement for cardiorespiratory support between the two populations, but there were significant differences (no GLVD vs. GLVD) in requirement for pacing (35% vs. 62%, P = 0.02), atrial fibrillation (20% vs. 41%, P = 0.03), QRS duration (92.0 (80.0 to 120.0) vs. 116.5 (95.0 to 154.0), P = 0.01) and QTc (460.0 (416.0 to 498.5) vs. 477.5 (451.2 to 541.0), P = 0.02). There was no significant difference in ejection fraction (no GLVD 43.0 (35.0 to 49.5) vs. GLVD 39.6 (29.5 to 49.7), P = 0.43), mitral regurgitation (40.5% vs. 62.5%, P = 0.06), or any other measures of LV systolic or diastolic function between the two groups. There was good correlation between the two methods used to assess dyssynchrony (LV t-IVT:LV Tei index correlation coefficient = 0.80, P <0.001).

Conclusion

GLVD that limits cardiac output is common in the cardiothoracic ICU, and significantly related to mortality. When diagnosed, the underlying cause should be sought and treatment instigated to minimize the t-iVT (pacing optimization/revascularization/ inotrope titration/volaemia optimization).

References

  1. Duncan A, et al.:

    J Am Coll Cardiol. 2003, 41:121-128. PubMed Abstract | Publisher Full Text OpenURL

  2. Tei C, et al.:

    J Am Coll Cardiol. 1996, 28:658-664. PubMed Abstract | Publisher Full Text OpenURL