What is disclosed is a system and method for detecting an arrhythmic or non-arrhythmic event from a cardiac signal obtained from a subject. In one embodiment, a plurality of different cardiac signals are received and are transformed into frequency domain signals which, in turn, are changed such that a dominant frequency in each of the signals is substantially aligned to form a matrix of feature vectors. The feature matrix is used to train a classifier. A cardiac signal from the subject is received and transformed to a frequency domain signal. The frequency domain signal is changed such that a dominant is substantially aligned with a dominant frequency of signals used to train the classifier. The subject's frequency domain signal is provided as a new feature vector to the classifier. The classifier uses the new feature vector to classify the subject as having an arrhythmic or a non-arrhythmic event.
