Discrimination of supraventricular tachycardia from sinus tachycardia of overlapping cycle length.

For more than 15 years, pulse generators (PG) have been implanted for the control of tachyarrhythmias. Manually activated systems have not achieved wide acceptance, mainly because of the need for direct patient participation. Automatic antitachycardia PGs have been limited by lack of flexibility of programmable parameters and the inability to discriminate pace-terminable tachycardias from sinus tachycardia. New algorithms for differentiating these tachycardias are becoming available. In addition to high rate detection criteria, there are three additional criteria that might characterize the tachycardias: (1) sudden onset, (2) rate stability, (3) sustained high rate. Future antitachycardia pacing systems will be able to employ even more elaborate algorithms when more sophisticated microprocessor capabilities and new sensors become available.