A cardiac monitoring system includes a communication subsystem, a comparison module, and a display module. The communication subsystem receives literal data from a cardiac medical device. The literal data includes cardiac signals and marker data. The cardiac signals represent electrical activity of a heart that is sensed by the medical device. The marker data represents one or more algorithms running on the medical device. The comparison module compares the cardiac signals and marker data to one or more heuristic rules to derive heuristic information about the cardiac signals and the marker data. The heuristic information represents a relationship among the cardiac signals and the marker data. The display module directs a display device to visually present the cardiac signals and a visual indicator representative of the heuristic information. The heuristic information can assist an operator, such as a physician, in changing one or more algorithms running on the medical device.
