European Journal of Echocardiography Advance Access originally published online on June 16, 2009
European Journal of Echocardiography 2009 10(7):847-857; doi:10.1093/ejechocard/jep088
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The shape of the aortic outflow velocity profile revisited: is there a relation between its asymmetry and ventricular function in coronary artery disease?
1 Department for Cardiovascular Diseases, University Hospital Centre Zagreb and School of Medicine, University of Zagreb, Kispaticeva 12, 10000 Zagreb, Croatia
2 Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, 10000 Zagreb, Croatia
3 St. George's Hospital, Blackshaw Road, London SW17 0QT, UK
4 University of Leuven, Herestraat 49, 3000 Leuven, Belgium
5 ICREA – UPF, Barcelona, Spain
Received 2 April 2009; accepted after revision 23 May 2009; online publish-ahead-of-print 16 June 2009.
* Corresponding author. Tel: +385 1 2367501; fax: +385 1 2367512. E-mail address: maja_cikes{at}yahoo.com
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Abstract |
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Aims: Myocardium contracts in the beginning of ejection causing outflow acceleration, resulting in asymmetric outflow velocity profiles peaking around one-third of ejection and declining when force development declines. This article aimed to demonstrate that decreased contractility in coronary artery disease (CAD) changes outflow timing and profile symmetry.
Methods and results: Seventy-nine patients undergoing routine full dose dobutamine stress-echo (DSE) were divided into two groups based on resting wall motion and DSE response: DSE negative (DSEneg) (35 of 79 patients) and positive (DSEpos) (44 of 79 patients) which were compared with 32 healthy volunteers. Aortic CW-Doppler traces at rest were analysed semi-automatically; time-to-peak (Tmod), ejection-time (ETmod), rise-time (trise), and fall-time (tfall) were quantified. Asymmetry (asymm) was calculated as the normalized difference of left and right half of the spectrum. Normal curves were triangular, early-peaking, whereas patients showed more rounded shapes and later peaks. Trise was longest in DSEpos. Tfall was shortest in DSEpos, followed by controls and DSEneg. Asymm was lowest in DSEpos, followed by controls and DSEneg. Abnormally symmetric profiles (asymm <0.25) were found in none of the controls, 2.9% DSEneg, and 27.3% DSEpos. A good correlation was found between assym and ejection fraction (EF) and Tmod/ETmod and EF. Notably, an LV dynamic gradient was induced in 71.4% DSEneg and in 18.2% DSEpos, associated with LV hypertrophy and supernormal (very asymmetric) traces.
Conclusion: Decreased myocardial function results in a more symmetrical outflow, while very asymmetrical traces suggest increased contractility, potentially inducing intra-cavity gradients during DSE. Therefore, including outflow symmetry as a clinical measurement provides additional information on patients with CAD.
Keywords: Left ventricular outflow trace; Doppler echocardiography; Dobutamine stress echocardiography; Left ventricular function; Haemodynamics