The method and system of the present invention detects cellular electrical activity and/or temperature continuously in real time to indicate the level of cellular arrest in the myocardial and conductive cells, allowing for the adjustment of cardioplegia, temperature, and/or increasing or decreasing the ratio of blood to electrolytes (cardioplegia) in order to eliminate or minimize myocardial ischemia that occurs when cellular arrest is not obtained or maintained during cardiac surgery. In a preferred embodiment of the present invention, a conductive wire and/or a thermistor are imbedded in or on the walls of a retrograde and/or other cannula to detect low amplitude electrical activity and/or temperature, respectively. In an alternate preferred embodiment of the present invention sensors for electrolyte, pO2, pCO2, or cardiac enzymes could also be added or used in replacement of other sensors.
