1. A system for classifying cardiac arrhythmias, the system comprising: a signal input to receive a cardiac signal indicative of a detected arrhythmia episode; an irregularity analyzer coupled to the signal input, the irregularity analyzer adapted to produce an irregularity parameter indicative of a degree of cycle length irregularity of the cardiac signal; a complexity analyzer coupled to the signal input, the complexity analyzer adapted to produce a complexity parameter indicative of a degree of morphological complexity of the cardiac signal; and an arrhythmia classifier coupled to the irregularity analyzer and the complexity analyzer, the arrhythmia classifier adapted to classify the detected arrhythmia episode based on the irregularity parameter and the complexity parameter.