Automated analysis of myocardial deformation at dobutamine stress echocardiography: an angiographic validation.
OBJECTIVE
We investigated the accuracy of automated analysis of myocardial deformation during dobutamine stress echocardiography (DSE).


BACKGROUND
The time required for segmental measurement of strain rate imaging (SRI) limits its feasibility for quantification of DSE.


METHODS
Myocardial deformation was assessed at DSE in 197 patients, 76 with and 61 without coronary artery disease (CAD) at angiography, and 60 at low risk of CAD. Automated deformation analysis was based on velocity gradient and segment length methods of measuring longitudinal motion within a region of interest tracked through the cardiac cycle. Results were compared with independent wall motion scoring (WMS). Patients were randomly divided; group A (n = 69) established optimal cutoffs for the parameters and group B (n = 68) tested their accuracy.


RESULTS
The feasibility of WMS exceeded that of both SRI methods at rest and at peak stress. In group A, the area under the receiver-operating characteristics curve of the peak systolic strain rate was 0.90 by both methods, and the optimal cutoffs for detection of CAD were -1.3 (velocity gradient) and -1.2 s(-1) (segment length). The areas under the receiver-operating characteristics curves for end-systolic strain were less (0.87) by both methods, with respective cutoffs of 9% and 8%. In group B, the velocity and segment length methods had respective sensitivities of 87% and 84% for SR, and 87% and 88% for end-systolic strain. Both significantly exceeded that of WMS in the same group (75%).


CONCLUSIONS
Automated analysis of myocardial deformation at DSE is feasible and accurate, and may increase the sensitivity of expert conventional reading.
Bjork Ingul
Charlotte
C
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; University of Queensland, Brisbane, Australia.
Stoylen
Asbjorn
A
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
Slordahl
Stig A
SA
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
Wiseth
Rune
R
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
Burgess
Malcolm
M
University of Queensland, Brisbane, Australia.
Marwick
Thomas H
TH
University of Queensland, Brisbane, Australia.. Electronic address: tmarwick@uq.edu.au.
D000368:Aged; D001331:Automation; D017023:Coronary Angiography / Q000379:methods*; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D015588:Observer Variation; D011336:Probability; D012372:ROC Curve; D018570:Risk Assessment; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index