Objective quantification of global and regional left ventricular systolic function by endocardial tracking of contrast echocardiographic sequences. by Bermejo, J, Timperley, J, Odreman, R, Mulet, M, Noble, J, Banning, A, Yotti, R, Pérez-David, E, Declerck, J, Becher, H, García-Fernández, M