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Septal and lateral wall myocardial velocity-time curves from tissue Doppler imaging were analyzed to determine wall motion from which the velocity originated in 34 patients with left bundle branch and systolic dysfunction (ejection fraction <45%). Longitudinal strain rate by speckle tracking imaging was assessed to identify whether corresponding wall motion was active or passive. All lateral peak velocities during the ejection period were derived from delayed active movement. However, septal peak velocities (Vsp) were more numerous and complex. Vsp during pre-ejection was derived from first active movement in 29 patients (85.2%). Vsp during the ejection period was derived from second active movement in 20 patients, passive movement in 9 patients, and first active movement in only 5 patients. Because Vsp was consistent with various wall motion types, identification of Vsp origin including that during pre-ejection may be important in identifying LV dyssynchrony based on propagation of first active myocardial movements.