SYSTEM AND METHOD FOR PREDICTING VENTRICULAR TACHYCARDIA BY DERIVATIVE ANALYSIS

A system for predicting ventricular tachycardia from electrocardiograph input waveforms. A high pass filter provides an output responsive to the input waveforms. A time derivative of the filter output is generated to produce waveforms which can be compared to a standard. In one embodiment, the input waveforms are digitized prior to processing by the filter means. In another embodiment, digitized input waveforms are signal averaged prior to processing by the filter. The filter can be a finite impulse response filter of an infinite impulse response filter. In an alternate embodiment, a ventricular tachycardia prediction system for use with ECG waveforms having cyclical characteristics is disclosed. The ECG waveforms are periodically sampled during each of a plurality ECG cycles. A filter unidirectionally filters the signals for each ECG cycle so as to provide a filter output systematically related to the high frequency content of the input. A reference signal is provided for ventricular tachycardia prediction. The filter output is compared to the reference signal, and a propensity for episodes of ventricular tachycardia is indicated responsive to the comparison.