title: The relation between viable segments and left ventricular ejection fraction improvement.
abstract: For patients with coronary artery disease and left ventricular dysfunction who undergo revascularization, it is important to estimate the left ventricular ejection fraction (LVEF) improvement after revascularization, as this is a strong indicator of the long-term outcome. Identification of viable segments from echocardiography has been considered a predictive sign of LVEF improvement. However, a quantitative relation between segmental function recovery and global ejection fraction improvement has not been established. There is a clinical need to determine parameters that are predictive to LVEF improvement. A cylindrical left ventricular model is proposed to establish the relation between segmental myocardial function and LVEF based on a 12-segment echocardiograph model. Model results show that LVEF improvement is directly related to the contraction ratio in normal segments and a weighted sum of the number of viable segments that recover to normal or hypokinetic, which is equal to a weighted sum of the change in wall motion scores. This new combined parameter is a better predictor of the amount of LVEF improvement than the total number of viable segments or preoperative ejection fraction. The predictive value of the model was illustrated in a group of four patients with coronary artery disease who underwent revascularization.
authors.affiliation: Department of Mechanical Engineering & Biomechanics, The University of Texas at San Antonio, San Antonio, TX, USA. hchan@utsa.edu
authors.forename: H-C
authors.initials: HC
authors.lastname: Han
authors.forename: S
authors.initials: S
authors.lastname: Lerakis
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D006334:Heart Function Tests / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008955:Models, Cardiovascular; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D014022:Tissue Survival; D016896:Treatment Outcome; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery