A shock is delivered on the T-wave of a patient's cardiac waveform by first
detecting the occurrence of a QRS complex in the waveform and using that
detection to set up for detection of the following T-wave. Narrowband
filtering is used to first select the QRS complex and thereafter the
T-wave, while peak detection is employed to define the actual occurrence
of the respective waveforms. The capability is also provided to deliver
the shock at a manually selected interval after QRS detection or after a
coupling interval in a pacing application.
