A rapid and efficient method and apparatus for detecting electrophysiologic, proarrhythmic, contractile, and other effects of substances such as compounds and drugs in native cellular cardiac preparations, the preparations representing an integrated cell-based pharmacologic response is disclosed. More specifically, a method to (1) rapidly and efficiently detect and verify the effects of chemicals, compounds and drugs on cardiac repolarization, contractility, and excitability using optically based techniques and customized simulation protocols, and (2) rapidly and efficiently screen and select compounds for electrophysiologic and proarrhythmic effects on cardiac myocytes is disclosed.