Tachycardia recognition algorithms for implantable systems

The detection algorithm of current antitachycardia pacing systems incorporates derivatives of heart rate as the only objective parameter used for recognition. Present pacing systems use one or more rate-related parameters: (1) rate cutoff, (2) sudden onset, (3) rate stability, and (4) sustained high rate. Recently, the development of antitachycardia systems has focused on combining the four detection criteria to form multiple recognition algorithms. Nevertheless, inability to differentiate between supraventricular and ventricular tachycardias at compatible rates remains a limitation. Incorporating atrial sensing capability, in addition to ventricular sensing capability, an alternative strategy that potentially could enhance diagnostic accuracy, is discussed. The incorporation of time and frequency analysis, arterial pressure, and stroke volume are also examined.<>