title: Application of three-dimensional speckle tracking echocardiography to assess left ventricular regional work using wall tension-regional area loop.
abstract: Three-dimensional (3-D) speckle tracking echocardiography allows us to track a change in regional endocardial surface area. The change of regional area during a cardiac cycle should be useful for assessing left ventricular regional work. We investigated the feasibility of assessing regional work, calculated as the area within the wall tension-regional area (T-A) loop using 3-D echocardiography. Three-dimensional full-volume images were acquired using 3-D echocardiography (Artida, Toshiba) at baseline and during brief occlusion of the left circumflex coronary artery in eight dogs. Wall tension was calculated according to Laplace's law for a spherical model. Area change ratio (in %) determined by area tracking was transformed into a change of regional area (in cm(2)) by a custom software. We calculated the area within the T-A loop (TAA) in the area under transient ischemia (risk area) and the remote area as regional work and validated the T-A loop method by comparing the global integral of TAA with the total work assessed by the pressure-volume loop. During coronary occlusion, regional work for the risk area significantly decreased (baseline vs. occlusion, 26.8 ± 10.7 vs. 18.4 ± 7.8 mmHg·cm(3); P < 0.05), whereas that for the remote area did not change. The global integral of TAA closely correlated with the total work assessed by the pressure-volume loop (r = 0.91, P < 0.0001). The wall T-A loop reflected regional dysfunction caused by myocardial ischemia. This analysis using 3-D speckle tracking echocardiography might be useful to quantify left ventricular regional work.
authors.affiliation: Division of Functional Diagnostics, Department of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; and.
authors.forename: Ayana
authors.initials: A
authors.lastname: Hioki
authors.affiliation: Division of Functional Diagnostics, Department of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; and.
authors.forename: Kasumi
authors.initials: K
authors.lastname: Masuda
authors.affiliation: Division of Functional Diagnostics, Department of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; and.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Asanuma
authors.affiliation: Cardiology Division of Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Division of Functional Diagnostics, Department of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; and nakatani@sahs.med.osaka-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakatani
mesh_terms: D000818:Animals; D054059:Coronary Occlusion / Q000000981:diagnostic imaging; D004285:Dogs; D019560:Echocardiography, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D016277:Ventricular Function, Left
keywords: cardiac function; pressure-volume loop; three-dimensional echocardiography; ventricular work