regulates biological regulation regulation of cardiac muscle cell contraction atrial cardiac muscle cell action potential regulation of cardiac muscle cell action potential regulation of atrial cardiac muscle cell action potential Any process that modulates the frequency, rate or extent of action potential creation, propagation or termination in an atrial cardiac muscle cell contributing to the regulation of its contraction. This typically occurs via modulation of the activity or expression of voltage-gated ion channels. 2011-11-10T08:49:13Z tb biological_process GO:0098910 regulation of cardiac conduction