Patent ID: 8437851

Claim:
A method comprising: monitoring a heart of a patient for cardiac cycle lengths; determining a degree of variability of the cardiac cycle lengths; automatically differentiating, by a processor, premature cardiac events from atrial fibrillation based on the determined degree of variability; analyzing, by the processor, a morphology of the premature cardiac events, wherein analyzing the morphology of the premature cardiac events comprises analyzing the morphology of the premature cardiac events to identify similarity of R-wave amplitude, polarity, and duration; differentiating, by the processor, premature atrial contractions from premature ventricular contractions based on the analysis, wherein the premature cardiac events comprise at least one of the premature atrial contractions and the premature ventricular contractions; measuring a coupling interval between R-waves; and identifying the premature cardiac events as premature ventricular contractions when the analysis includes R-waves of differing amplitude, polarity, and duration and the measurement indicates a constant coupling interval.