Echocardiogram showing simultaneous display of B-mode and M-mode images of left ventricle. LVDd=Left ventricular internal diameter at diastole, LVDs=Left ventricular internal diameter at systole, IVSd=Interventricular septum thickness at diastole, IVSs=Interventricular septum thickness at systole, LVPWd=Left ventricular posterior wall thickness at diastole, LVPWs=Left ventricular posterior wall thickness at systole.