What is disclosed is a system and method for classifying a time-series signal as ventricular premature contraction in a subject being monitored for cardiac function assessment. One embodiment hereof involves first, receive a time-series signal which contains frequency components that relate to the function of the subject's heart. Signal segments of interest are identified in the time-series signal. Time-domain features comprising the peak-to-peak interval between cardiac pulses and pulse amplitudes are extracted for each signal segment of interest. The time-domain features are arranged into a two dimensional feature vector. Each feature vector is associated with a respective signal segment. A magnitude of each signal segment's respective feature vector is determined. Signal segments are classified as being ventricular premature contraction based on each segment's associated magnitude. In one embodiment, signal segments with associated feature vectors having a smallest magnitude are classified as being ventricular premature contraction.
