Natural myocardial markers, or speckles, originated from constructive and
destructive interference of ultrasound in the tissues may provide early
diagnosis of myocardial changes and be used in the prediction of some cardiac
events. Due to its relatively temporal stability, speckles can be tracked by
dedicated software along the cardiac cycle, enabling the analysis of the
systolic and diastolic function. They are identified by either conventional 2D
grey scale and by 3D echo, conferring independence of the insonation angle, thus
allowing assessment of cardiac mechanics in the three spatial planes:
longitudinal, circumferential, and radial. The purposes of the present paper
are: to discuss the role and the meaning of cardiac strain obtained by speckle
tracking during the evaluation of cardiac physiology and to discuss clinical
applications of this novel echocardiographic technology.