1. A system for classifying cardiac arrhythmias, the system comprising: a tachyarrhythmia detector adapted to detect an arrhythmia episode; a template waveform input to receive template data representative of a template waveform associated with a template heart beat, the template waveform sensed during a normal sinus rhythm; an arrhythmic waveform input to receive arrhythmic data representative of an arrhythmic waveform associated with an arrhythmic heart beat sensed during the detected arrhythmia episode; an arrhythmic heart rate input to receive an arrhythmic heart rate parameter representative of an arrhythmic heart rate associated with the detected arrhythmic episode; a rate-dependent feature locator coupled to the template waveform input, the arrhythmic waveform input, and the arrhythmic heart rate parameter input, the rate-dependent feature locator adapted to dynamically determine morphological feature locations each as a function of at least the arrhythmic heart rate parameter in response to the detected arrhythmia episode, the morphological feature locations including template feature locations each representative of timing of a plurality of template morphological features on the template waveform and arrhythmic feature locations each representative of timing of a plurality of corresponding arrhythmic morphological features on the arrhythmic waveform; and a feature extracting module coupled to the rate-dependent feature locator, the feature extracting module adapted to extract the plurality of template morphological features from the template waveform at the dynamically determined morphological feature locations and to extract the plurality of corresponding arrhythmic morphological features from the arrhythmic waveform at the dynamically determined morphological feature locations.