M-mode echocardiographic image of left ventricular measurements made using the Teichholz's method. The papillary muscles and chordae tendineae of the right ventricle (open arrowhead) and left ventricle (white arrowheads) gradually disappeared with a contrast injection. The internal dimension of the left ventricle is widened by the contrast injection. Note the contrast between the ventricular walls and the contrast-filled left ventricle.RV, right ventricle; IVS, inter-ventricular septum; LV, left ventricle; LVPW, left ventricular posterior wall; IVSd, interventricular septum thickness in diastole; IVSs, interventricular septum thickness in systole; LVIDd, left ventricular internal dimension in diastole; LVIDs, left ventricular internal dimension in systolic; LVPWd, left ventricular posterior wall thickness in diastole; LVPWs, left ventricular posterior wall thickness in systole.