A system is provided which processes cardiac condition data representative of heart electrical signals to identify a cardiac condition. An acquisition processor is conditioned for acquiring data representing a sequence of successive pulses of a type of electrical heart waveform of a patient. A computation processor is electrically coupled to the acquisition processor and is conditioned for calculating a pulse interval irregularity measure based on a sum of time interval differences occurring between pairs of successive pulses of the sequence of successive pulses and excluding time interval differences exceeding a predetermined maximum threshold from the sum. The computation processor is further conditioned to compare a calculated pulse interval irregularity measure with a predetermined irregularity measure threshold. An output processor is electrically coupled to the computation processor and conditioned for generating data representing an alarm message in response to the calculated pulse interval irregularity measure exceeding the predetermined threshold.
