title: Detection of the cardiac activation sequence by novel echocardiographic tissue tracking method.
abstract: Asynchronous cardiac activation leads to decreased pumping efficiency. Quantifying the activation sequence may optimize both the selection of patients for cardiac resynchronization therapy (CRT) and its efficacy. The feasibility of assessing the directivity and the degree of synchronous activation with ultrasound was examined. A tissue tracking method (CEB, GE-Ultrasound, AFI, GE Healthcare Inc., Wauwatosa, WI, USA) provided the regional strain profiles. The first maxima in systole of the regional circumferential strains were considered as the activation times. An integrative vector (SDV) describes the activation synchrony and directivity. In six open-chest sheep, activation maps and SDV were calculated in short-axis planes of the left ventricle for normal activation and induced pacings from the anterior and lateral free walls. Both magnitude and angle of the SDV were statistically different (p < 0.05) for the different pacings. Localization of the pacing site was 3 degrees +/- 18 degrees from true position. Conclusions were that motion analysis in echocardiograms provides insightful information regarding the activation process and may enhance procedures such as CRT.
authors: Department of Biomedical Engineering, Technion-IIT Technion City, Haifa, Israel.
authors: Dan
authors: D
authors: Rappaport
authors: Eugene
authors: E
authors: Konyukhov
authors: Lilia
authors: L
authors: Shulman
authors: Zvi
authors: Z
authors: Friedman
authors: Peter
authors: P
authors: Lysyansky
authors: Amir
authors: A
authors: Landesberg
authors: Dan
authors: D
authors: Adam
mesh_terms: D000818:Animals; D002304:Cardiac Pacing, Artificial / Q000379:methods; D004452:Echocardiography / Q000379:methods*; D004562:Electrocardiography; D006321:Heart / Q000502:physiology*; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000502:physiology; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D023421:Models, Animal; D012756:Sheep; D013314:Stress, Mechanical; D013997:Time Factors; D016276:Ventricular Function / Q000502:physiology