Fig. 4. In the upper panel, individual values of Doppler stroke index (SI) are plotted against simultaneous measurements of left ventricular ejection fraction in the long axis (LVEF;top left ) or left ventricular area contraction in the short axis (LVFAC;top right ). In the lower panel, the same values of Doppler SI are plotted against simultaneous measurements of left ventricular end-diastolic volume in the long axis (LVEDV;bottom left ) or left ventricular end-diastolic area in the short axis (LVEDA;bottom right ).