Figure A.1.

A. Schematics of sarcomere geometry. Actin filaments have equal length in each half-sarcomere. Myosin-heads are attached on the thick filament which runs across the sarcomere. Along the M-line is region where there are no myosin-heads (also known as the bare region). It is assumed that length of thick-thin filament overlap influences binding affinity of Ca²⁺ with TrpC and hence affects forward cross-bridge cycling. B. Mechanics of cardiac muscle force generation. F_pas represents passive forces of the cardiac muscle due to titin or collagen, F_act is the active force generated due to myosinactin interaction, η is the viscosity of the cardiac muscle, and F_SE = K_SE (SL_set − SL) is the force due to series elastic element used to simulate isosarcometric contraction. K_SE is the stiffness of series element; SL_set is the set sarcomere length and SL is the sarcomere length.