1. A system for classifying tachyarrhythmias, the system comprising: a feature vector generation circuit configured to produce a template feature vector ( a ) using a plurality of template morphological features on a plurality of template waveforms each associated with a template heart beat of a known type cardiac rhythm, an arrhythmic feature vector ( b ) using a plurality of arrhythmic morphological features of an arrhythmic waveform associated with an arrhythmic heart beat sensed during a tachyarrhythmia, and a maximum feature vector ( a max ) and a minimum feature vector ( a min ) using the plurality of template morphological features, the plurality of arrhythmic morphological features, the maximum feature vector ( a max ) and the minimum feature vector ( a min ) being within a template band associated with predetermined confidence levels of the plurality of template morphological features; a correlation computing circuit coupled to the feature vector generation circuit, the correlation computing circuit configured to calculate a mean feature correlation coefficient (Fcc mean ) using the template feature vector ( a ) and the arrhythmic feature vector ( b ), a maximum feature correlation coefficient (Fcc max ) using the maximum feature vector ( a max ) and the arrhythmic feature vector ( b ), and a minimum feature correlation coefficient (Fcc min ) using the minimum feature vector ( a min ) and the arrhythmic feature vector ( b ); and a beat classification circuit coupled to the correlation analysis circuit, the beat classification circuit configured to classify the arrhythmic heart beat using the mean feature correlation coefficient (Fcc mean ), the maximum feature correlation coefficient (Fcc max ), the minimum feature correlation coefficient (Fcc min ), and at least one predetermined correlation threshold.