Document Detail

Dual level sensing significantly improves automatic threshold control for R wave sensing in implantable defibrillators. The Angeion Corporation.
MedLine Citation:
PMID:  8994943     Owner:  NLM     Status:  MEDLINE    
ICDs must sense R waves over a range of amplitudes without sensing P or T waves. Automatic threshold control (ATC) is an accepted sensing method for that task. ATC sensing levels are from 25%-75% of the electrogram (EGM) peak, decreasing with an exponential decay. A high sensing level for a time after peak detection may better allow ATC to pass over a T wave, while a lower sensing level thereafter may better allow ATC to sense the next R wave. An ATC was designed with two sensing levels and time constants (tau), using a 58% level (tau = 1.75 s) for 325 ms after peak detection switching to 33% (tau = 1.1 s) thereafter, and was compared to a single level ATC (sensing level = 50%, tau = 1.4 s). The two ATC circuits were tested with 22 arrhythmia EGMs to determine sensitivity and specificity rates at +/-1-, 2-, 5-, 10-, and 20-mV amplitudes. It was confirmed that a dual level ATC significantly improves the sensitivity rate without degrading the high specificity rate of a standard sensing circuit.
J E Brewer; J S Perttu; M W Kroll; A M Donohoo
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Pacing and clinical electrophysiology : PACE     Volume:  19     ISSN:  0147-8389     ISO Abbreviation:  Pacing Clin Electrophysiol     Publication Date:  1996 Dec 
Date Detail:
Created Date:  1997-04-04     Completed Date:  1997-04-04     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7803944     Medline TA:  Pacing Clin Electrophysiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2051-9     Citation Subset:  IM    
Angeion Corporation, Minneapolis, Minnesota, USA.
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MeSH Terms
Arrhythmias, Cardiac / diagnosis*
Defibrillators, Implantable*
Equipment Design
Sensitivity and Specificity

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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