Spatiotemporal Quantification of In Vitro Cardiomyocyte Contraction Dynamics Using Video Microscopy-based Software Tool

Stem cell derived cardiomyocytes provide a platform for a variety of studies. The typically performed electrophysiological measurements do not describe the primary function of these cells, contraction and its biomechanics. Video microscopy-based analysis of motion has become a feasible option for these studies. Here, we demonstrate methods for spatiotemporal quantification of stem cell derived cardiomyocytes, implemented in an in-house developed MATLAB-based software tool. The tool is capable of characterizing cardiomyocyte contraction with minimal user bias. The results show that automatic segmentation using a power spectral density -based measure enables segmentation based on contractile function. Further, based on segmented boundaries, we introduce automatically calculated parameters for quantification the contractile function and its propagation through the cell culture based on timings of different contraction phases. The methods presented here form a basis for quantifying and understanding the contraction dynamics and the propagation of contraction in cultures involving cardiomyocytes.