Tachycardia detection by antitachycardia devices: present limitations and future strategies.

Early experience with three generations of implantable devices has demonstrated the need to further refine the accuracy of automated rhythm analysis. Although initial experience with commercially utilized morphological waveform analysis has been disappointing, other time and frequency domain electrogram features have been developed and show potential promise for future devices. While single chamber algorithms for rate and rate variations have theoretical appeal because of their limited power demands, practical experience has demonstrated that inaccurate arrhythmia diagnosis continues to occur by antitachycardia devices that utilize them. Technological advancement in hardware manufacturing and the design of increasingly more efficient software algorithms for tachycardia detection will continue to yield lower power digital circuitry, to increase device battery power and life, and to permit more and more accurate automated arrhythmia diagnosis and treatment by antitachycardia devices. Two chamber sensing has been available for decades in dual chamber antibradycardia pacemakers. The introduction of this technology into antitachycardia devices is not only inevitable but should dramatically improve the precision of diagnosis in future generation devices.