"Any process that modulates the frequency, rate or extent of heart contraction. Heart contraction is the process by which the heart decreases in volume in a characteristic way to propel blood through the body [goid 8016] [pmid 15542288] [evidence IMP]; The sliding of actin thin filaments and myosin thick filaments past each other in muscle contraction. This involves a process of interaction of myosin located on a thick filament with actin located on a thin filament. During this process ATP is split and forces are generated [goid 30049] [pmid 15923195] [evidence IDA]; The sliding of actin thin filaments and myosin thick filaments past each other in muscle contraction. This involves a process of interaction of myosin located on a thick filament with actin located on a thin filament. During this process ATP is split and forces are generated [goid 30049] [pmid 12186860] [evidence IDA]; Any process that stops or reduces the rate of ATP hydrolysis by an ATPase [goid 32780] [pmid 12093807] [evidence IDA]; Any process that stops or reduces the rate of ATP hydrolysis by an ATPase [goid 32780] [pmid 10850966] [evidence IDA]; Any process that stops or reduces the rate of ATP hydrolysis by an ATPase [goid 32780] [pmid 12093807] [evidence IDA]; Any process that activates or increases the rate of ATP hydrolysis by an ATPase [goid 32781] [pmid 12186860] [evidence IDA]; Any process that activates or increases the rate of ATP hydrolysis by an ATPase [goid 32781] [pmid 10850966] [evidence IDA]; A change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a calcium ion stimulus [goid 51592] [pmid 2530435] [evidence IDA]; A change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a calcium ion stimulus [goid 51592] [pmid 8205619] [evidence IMP]; A change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a calcium ion stimulus [goid 51592] [pmid 2530435] [evidence IDA]; The process by which the anatomical structures of cardiac ventricle muscle is generated and organized. Morphogenesis pertains to the creation of form [goid 55010] [pmid 16754800] [evidence IMP]"