What is the ideal rate-adaptive sensor for patients with implantable cardioverter defibrillators: Lessons from cardiac pacing

The development of implantable pacemakers in the clinical setting mirrors t he implementation of advanced technical possibilities, In the United States , 83% of all pacemakers implanted in 1996 had rate response as a programmab le option. A variety of sensors have been proposed and used for rate contro l. Among today's many concepts, accelerometer-controlled pacing is the most widely used rate-adaptive principle, Although the use of a second sensor i s currently of proven benefit for only a limited number of patients, the co ncept of closed-loop pacing-implementing a negative feedback between pacing rate and the control signal-merits further investigation, This is of speci al importance in defibrillator patients whose myocardial contractility is g enerally limited. These patients are most sensitive to pacing rates that ar e too high for a given metabolic situation. The integration of rate-adaptiv e pacing into defibrillators is a natural consequence of the technical evol ution. (C) 1999 by Excerpta Medico, Inc.