What is disclosed is a system and method for assessing risk for ventricular tachycardia from a time-series signal of a patient monitored for cardiac function assessment. One embodiment involves receiving a time-series signal which contains frequency components that relate to the function of the subjects heart. Signal segments of interest are identified in the time-series signal. Time-domain features 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 segments respective feature vector is determined. Signal segments are classified as being ventricular premature contraction based on each segments associated magnitude. If at least three consecutive signal segments or at least three consecutive portions of the same signal segment have been classified as ventricular premature contraction, then the subjects risk of a ventricular tachycardia is assessed as elevated.
