Fig. 1

Schematic representation of left ventricular segmentation for strain analysis in the transgastric short-axis view of the heart at the mid-papillary level (upper left panel), with the overimposition of the segmental matrix on the frozen two-dimensional image (upper right panel). Each LV segment strain curve is color-encoded and the mean strain curve is displayed as a white dotted curve over-imposed on individual LV segment curves, with the time of aortic valve closure (AVC) indicated by the white vertical dotted line (lower panels). Illustrative examples of a normal septal pattern of contraction (grade 0, mid left panel) and of increasing severity of paradoxical septal motion, such as transient septal flattening (grade 1, mid right panel), sustained septal flattening (grade 2, lower left panel) or inversed septal bulging (grade 2, lower right panel) with abnormal left ventricular segmental strain curve patterns are shown (white arrows). In the presence of a normal septal motion, left ventricular segmental strain curves exhibited a uniform pattern consistent with a homogeneous regional contraction, and the peak of radial strain occurred before the aortic valve closure (mid left panel). In contrast, patients with acute cor pulmonale presented with abnormal left ventricular strain curve patterns (lower panels, white arrows). A change in the pattern of the mid-antero-septal (yellow) and/or mid-infero-septal (red) strain curves was observed: the peak was delayed (i.e., time-to-peak increased) and occurred typically after aortic valve closure. In addition, the amplitude of the delayed peak appeared related to the severity of the paradoxical septal motion when semi-quantitatively assessed using two-dimensional imaging (septal flattening vs inversed septal bulging, lower panels). Of note, the mid-infero-lateral (purple) and mid-antero-lateral (green) strain curves mirrored the abnormal pattern of left ventricular mid-antero-septal and mid-infero-septal myocardial segment, respectively (lower panels). AVC: aortic valve closure; LV: left ventricle; RV: right ventricle; MIS, mid-infero-septal segment; MAS, mid-antero-septal segment; MA; mid-anterior segment; MAL, mid-antero-lateral segment; MIL, mid-infero-lateral segment; MI, mid-inferior segment