(Top) Typical LV longitudinal myocardial velocity curves obtained with spectral TD from the most basal segment of septum ( insertion ). The respective curves were traced at the outer and the inner border of the velocity waveform and mean velocity was calculated by averaging spectral maximal and minimal velocity. The respective curves were integrated over time to yield VTImax and VTImin. Mean velocity time integral (VTImean) was determined by averaging VTImax and VTImin. (Bottom) Typical colour-coded M-mode image of LV longitudinal myocardial motion acquired at basal septum 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 .