Fig. 1.

Simplified schematic representation of the two main cytoskeletal multiprotein complexes in cardiomyocytes a sarcomeres and b the intercalated disc. The sarcomere or the region between two Z-discs is the basic contractile unit of myofibrils, consisting of thin (actin and associated proteins, horizontal blue lines), thick (myosin and associated proteins, horizontal yellow block) and elastic (titin, horizontal pink line) filaments. Intercalated disc was originally described to consist of adherens junctions (blue and yellow symbols), desmosomes (pink symbols) and gap junctions (green symbols). The adherens junctions and desmosomes ensure transmission of force between neighbouring cardiomyocytes, allowing the heart to function in synchrony