A method and device of distinguishing premature contractions that includes a sensor sensing cardiac signals, and a processor configured to determine a plurality of R-waves in response to the sensed cardiac signal, detect a premature contraction being associated with a first R-wave of the plurality of R-waves, determine a first area of the detected first R-wave, compare the determined first area to an area threshold, and identifying the detected premature contraction as one of a premature atrial contraction or a premature ventricular contraction in response to the comparing.
