( Top ) Typical LV longitudinal myocardial velocity curves obtained with spectral TD at different offline gain settings from the most basal segment of septum ( insertion ). The respective curves were traced at the outer border of the velocity waveform as indicated and integrated over time to yield the corresponding longitudinal myocardial displacement values. Isovolumic contraction (IVCT) and relaxation (IVRT) periods as well as the chosen offline gain saturation are indicated. (Bottom) Typical colour-coded anatomic M-mode image of LV longitudinal myocardial motion acquired at basal septum (insertion) used for the measurements of systolic displacement. Boundaries of isovolumic contraction (IVCT) and relaxation (IVRT) periods were established by observing the specific colour bands expressing the reversal of velocity direction at the beginning and the end of systole.