1. A method for directly detecting an electromechanical wave propagation within a body structure of a subject, comprising: scanning, using ultrasound, said body structure during a predefined interval to acquire image data comprising a series of image frames directly representing the electromechanical wave, the series dividing a duration of the electromechanical wave, the scanning including a path along which the electromechanical wave propagates; performing a correlation calculation on the image frames to generate one or more correlation matrices representing relative displacements between successive image frames; detecting parameters of the electromechanical wave propagation within said body structure by analyzing the relative displacements in said correlation matrices; and generating a video graphically representing the body structure and the progression of the electromechanical wave over said path, wherein: the body structure includes at least a portion of a myocardium, artery, or aorta; the electromechanical wave: is a transient deformation arising directly from an electrical wave propagation in the body structure; propagates along a path of, during the predefined interval of, and in parallel itinerary with, the electrical wave propagation; the scanning is performed without inducement of motion other than the electromechanical wave representable as the displacements in said correlation matrices; the parameters include a time sequence of locations of a front of the electromechanical wave represented in the series of image frames; and the detecting includes: determining magnitudes of said relative displacements; selecting ones of the relative displacements occurring in said predetermined interval that possess magnitudes representative of the electromechanical wave; and estimating the time sequence of locations from the selected ones of the displacements.