Amazing Beating Cardiomyocytes! Watch Cardiomyocytes beating on our screenMATRIX. We are grateful to the James Smith/@SmithLabUEA Lab from the University of East Anglia for providing us this video. They have grown Cardiomyocytes tagged with alpha-actinin 1 on the screenMATRIX and recorded these amazingly looking and beating Cardiomyocytes.