A system improves characterization and diagnosis of cardiac electrophysiological activities by analyzing and characterizing cardiac function signals (including surface ECG signals and intra-cardiac electrograms) based on cardiac electrophysiological energy mode and pattern identification and mapping. The system accurately determines a time stamp, location and severity of cardiac pathology and clinical events by calculating a cardiac signal energy mode and energy variation and distribution. The system identifies cardiac disorders, differentiates cardiac arrhythmias, characterizes pathological severity, predicts life-threatening events, and supports evaluation of administration of drugs.
