  We have studied beating mouse cardiac syncytia $\textit{in vitro}$ in order
to assess the inotropic, ergotropic, and chronotropic effects of both
increasing and decreasing hydrostatic pressures. In particular, we have
performed an image processing analysis to evaluate the kinematics and the
dynamics of those pressure-loaded beating syncytia starting from the video
registration of their contraction movement. By this analysis, we have verified
the Frank-Starling law of the heart in $\textit{in vitro}$ beating cardiac
syncytia and we have obtained their geometrical-functional classification.
