This can be seen most dramatically in the case of premature ventricular contraction. The premature ventricular contraction causes early emptying of the left ventricle (LV) into the aorta. Since the next ventricular contraction will come at its regular time, the filling time for the LV increases, causing an increased LV end-diastolic volume. Because of the Frank-Starling law, the next ventricular contraction will be more forceful, causing the ejection of the larger than normal volume of blood, and bringing the LV end-systolic volume back to baseline.
The more the myocardium is dilated, the weaker it can pump, as it then reverts to Laplace's law.http://en.wikipedia.org/wiki/Frank-Starling_law_of_the_heart