Comparison of LVCM and RVCM. Diagrams presented here are consistent with our hypothesis where RVCM has less cTn (orange-filled circles in myofilament) and lower SERCA activity. The width of pipe represents the amount of Ca²⁺ flux between the subcellular domains, approximately. (1) RVCM showed smaller Ca²⁺ influx from VOCC_L and RYR due to short AP. Note that the pipe from VOCC_L and RYR of RVCM is thinner than that of LVCM. (2) The amount of Ca²⁺ flux to myofilament (J_TRPN) is smaller in RVCM due to the lower expression of the cTn complex. (3) Reflecting this difference, the free Ca²⁺ measured by Ca²⁺ indicator looks the same in height despite lower Ca²⁺ influx via VOCC_L and efflux via RYR. (4) The sarcomere shortening is also smaller in RVCM, with lower expression of cTn, the contraction apparatus. (5) The thinner duct implies the lower activity of SERCA, which is reflected in the slower Ca²⁺ decay and sarcomere relaxation in RVCM.