Effect of sensing system on the incidence of myopotential oversensing during bradycardia pacing in implantable cardioverter-defibrillators

Abstract

Oversensing during bradycardia pacing, sometimes leading to spurious tachyarrhythmia detection and inappropriately delivered shocks, has been reported with Ventritex (St. Jude Corporation, Sunnyvale, California) Cadence (models V-100 and V-110) implantable cardioverter-defibrillators (ICDs). 1 Kelly P.A. Mann D.E. Damle R.S. Reiter M.J. Oversensing during ventricular pacing in patients with a third-generation implantable cardioverter-defibrillator. J Am Coll Cardiol. 1994; 23: 1531-1534 Abstract Full Text PDF PubMed Scopus (47) Google Scholar , 2 Rosenthal M.E. Paskman C. Noise detection during bradycardia pacing with a hybrid nonthoracotomy implantable cardioverter defibrillator system. PACE. 1998; 21: 1380-1386 Crossref Scopus (9) Google Scholar , 3 Peters W. Kowallik P. Wittenberg G. Scholl C. Meesmann M. Inappropriate discharge of an implantable cardioverter defibrillator during atrial flutter and intermittent ventricular antibradycardia pacing. J Cardiovasc Electrophysiol. 1997; 8: 1167-1174 Crossref PubMed Scopus (15) Google Scholar One cause of this problem is sensing of diaphragmatic or abdominal myopotentials in the setting of the high sensitivity that automatically occurs during bradycardia pacing. 2 Rosenthal M.E. Paskman C. Noise detection during bradycardia pacing with a hybrid nonthoracotomy implantable cardioverter defibrillator system. PACE. 1998; 21: 1380-1386 Crossref Scopus (9) Google Scholar Ventritex ICDs use a stepwise automatic amplifier gain control, and amplifier gain is continuously maximal during bradycardia pacing, with a minimal sensed signal of approximately 0.2 mV. 4 Reiter M.J. Mann D.E. Sensing and tachyarrhythmia detection problems in implantable cardioverter-defibrillators. J Cardiovasc Electrophysiol. 1996; 7: 542-558 Crossref PubMed Scopus (60) Google Scholar Newer Ventritex devices, Cadet, Contour, and Angstrom (models V-115, V-145, V-180, and V-190) use a similar automatic gain control, although gain changes occur more rapidly than in the Cadence models. 5 Mann D.E. Damle R.S. Kelly P.A. Landers M. Otto L. Reiter M.J. Comparison of oversensing during bradycardia pacing in two types of implantable cardioverter-defibrillator systems. Am Heart J. 1998; 136: 658-663 Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar Other ICDs use different sensing algorithms. Medtronic (Minneapolis, Minnesota) and CPI Guidant (St. Paul, Minnesota) devices automatically adjust sensitivity or gain on a beat-by-beat basis. Sensitivity or gain is adjusted according to the amplitude of each sensed complex. Between complexes, sensitivity or gain exponentially increases, eventually reaching a maximum level that in some devices is programmable. In Medtronic and CPI devices, sensitivity or gain during bradycardia pacing is maximal for less of the cardiac cycle than in Ventritex devices, and thus the propensity to oversense could be less in these devices. 4 Reiter M.J. Mann D.E. Sensing and tachyarrhythmia detection problems in implantable cardioverter-defibrillators. J Cardiovasc Electrophysiol. 1996; 7: 542-558 Crossref PubMed Scopus (60) Google Scholar To assess the effect these differences in sensing function may have on oversensing of myopotentials, we performed the following prospective study.