Final answer:
Increased mitral valve leaflet excursion is not a typical finding in dilated cardiomyopathy; instead, DCM is characterized by things like apical mural thrombus, dilated and poorly functioning ventricular and atrial cavities.
Step-by-step explanation:
The question is about identifying the incorrect echocardiographic finding in dilated cardiomyopathy (DCM). DCM is characterized by a series of changes in the heart's structure and function including apical mural thrombus, dilated ventricular cavities, and enlarged atrial cavities. However, in contrast to these manifestations, increased mitral valve leaflet excursion is not typically seen in DCM. Instead, it might be seen in other conditions like mitral valve prolapse.
In dilated cardiomyopathy, the weakened and enlarged ventricles lead to reduced systolic function, which often results in less effective valve operation due to the dilatation. Therefore, instead of increased excursion, there might be functional regurgitation due to the inability of the mitral valve leaflets to close properly. This decreased efficacy of the mitral valve is due to the remodeling of the ventricular geometry, not due to increased leaflet motion.