European Journal of Echocardiography Advance Access originally published online on February 13, 2009
European Journal of Echocardiography 2009 10(5):613-618; doi:10.1093/ejechocard/jep010
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Validity of ejection fraction as a measure of myocardial functional state: impact of asynchrony
1 Department of Biomedical Physics, Ural State Medical Academy, 3 Repin Str., Ekaterinburg 620219, Russia
2 Department of Physics, Ural State University, 51 Lenin Ave., Ekaterinburg 620083, Russia
3 Therapeutic Department, City Clinic Preobrazhenskaya, 28 Gagarin Str., Ekaterinburg 620078, Russia
4 Diagnostics Department, Institute of Transplantology and Artificial Organs, 1 Sthukinskaya Str., Moscow 123182, Russia
Received 28 August 2008; accepted after revision 17 January 2009; online publish-ahead-of-print 13 February 2009.
* Corresponding author. Tel: +7 343 375 6548; fax: +7 343 261 6778. E-mail address: user-214{at}usu2.usu.ru
| Abstract |
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Aims: The goal of this study was to test whether peculiarities of left ventricular (LV) regional function place limits on the validity of ejection fraction (EF) as a measure of the myocardial functional state.
Methods and results: Transthoracic and transoesophageal data from patients with a variety of cardiac conditions were used for analysis of LV regional function. The focus was on the effects of mechanical asynchrony. Ejection fraction was calculated on the basis of LV end-diastolic volume and end-systolic volume obtained by two different ways: (i) end-systolic volume as a whole; and (ii) the sum of all regional end-systolic volumes (which may occur at different times). The relative difference, D-EF, between EFs obtained by (i) and (ii) was taken as the merit of EF. A value of zero is the highest merit. Irrespective of the examination method, we found that D-EF was always higher than zero, and that its value depended on the extent of mechanical asynchrony.
Conclusions: Ejection fraction is not the arithmetic average of regional EFs. An increase of asynchrony increases D-EF, i.e. it reduces the merit of EF as a measure of cardiac function.
Keywords: Left ventricle; Ejection fraction; Regional wall motion; Mechanical asynchrony; Ultrasound examination; 3D reconstruction