Left ventricular myocardial segmentation. The LV 17-segment model used for SPECT interpretation. Basal and mid-LV segments depicted in light gray are considered equal for LV lead placement. Apical segments and apex are depicted in dark gray. Numbers are in accordance with the clockwise method used for the fluoroscopic venogram in the left anterior oblique projection. The antero-lateral, infero-lateral and infero-septal segments correspond to the echocardiographic lateral, posterior and septal segments, respectively. Ant-Lat, antero-lateral; Inf-Lat, infero-lateral; Inf-Sept, infero-septal; RV, right ventricle.