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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2007-8-30
pubmed:abstractText
AIMS: In carriers of dual chamber pacemakers and implantable cardioverter-defibrillators (ICD), detection of atrial fibrillation (AF) is crucial for adequate mode switch function and to avoid inappropriate shock delivery. Detection algorithms rely on the atrial rate and on the relationship of atrial to ventricular intracardiac electrograms, but the relative portion of misclassified AF episodes remains high. Although myocardial impedance is a reliable indicator of contraction, little is known about atrial impedance as a marker of atrial arrhythmias. Methods During an electrophysiological study, we investigated the effect of induced AF on impedance at the right atrial free wall (RAFW) and right atrial appendage (RAA) in 20 patients. Using biphasic square-wave pulses (128 Hz, 200 microA/15 micros), impedance changes were recorded during sinus rhythm (SR-1), atrial pacing at 120 beats/min, AF induced by rapid atrial burst pacing, and after spontaneous AF termination (SR-2). Results At the RAA, peak-to-peak impedance amplitude during cardiac cycle (DeltaZ) dropped from 51.7 +/- 35.3 Omega (SR-1) or 49.6 +/- 30.6 Omega (pacing) to 24.6 +/- 22.0 Omega (AF, P< or =0.0005), and subsequently increased to 37.7 +/- 24.7 Omega (SR-2, P < or = 0.0004 v. AF). At the RAFW, DeltaZ changed from 16.2 +/- 15.5 Omega (SR-1) or 13.5 +/- 9.9 Omega (pacing) to 5.9 +/- 4.1 Omega (AF, P < or = 0.003), and to 11.4 +/- 10.7 Omega (SR-2, P < or = 0.015). Given a discrimination threshold of 65%, the sensitivity and the specificity of DeltaZ to detect AF were 79 +/- 18 and 89 +/- 14%, respectively (95% confidence interval). CONCLUSION: AF causes DeltaZ drop in pacemaker and ICD recipients. This impedance based algorithm can be used as an alternative method of AF detection.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1099-5129
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
812-6
pubmed:meshHeading
pubmed-meshheading:17545214-Aged, pubmed-meshheading:17545214-Aged, 80 and over, pubmed-meshheading:17545214-Algorithms, pubmed-meshheading:17545214-Arrhythmias, Cardiac, pubmed-meshheading:17545214-Atrial Fibrillation, pubmed-meshheading:17545214-Atrial Flutter, pubmed-meshheading:17545214-Cardiac Pacing, Artificial, pubmed-meshheading:17545214-Catheterization, pubmed-meshheading:17545214-Defibrillators, Implantable, pubmed-meshheading:17545214-Electric Countershock, pubmed-meshheading:17545214-Electrophysiologic Techniques, Cardiac, pubmed-meshheading:17545214-Electrophysiology, pubmed-meshheading:17545214-Female, pubmed-meshheading:17545214-Heart, pubmed-meshheading:17545214-Heart Atria, pubmed-meshheading:17545214-Humans, pubmed-meshheading:17545214-Male, pubmed-meshheading:17545214-Middle Aged, pubmed-meshheading:17545214-Pacemaker, Artificial, pubmed-meshheading:17545214-Sensitivity and Specificity
pubmed:year
2007
pubmed:articleTitle
Atrial fibrillation reduces the atrial impedance amplitude during cardiac cycle: a novel detection algorithm to improve recognition of atrial fibrillation in pacemaker patients.
pubmed:affiliation
Universitätsklinikum Freiburg, Medizinische Klinik III, Department of Cardiology and Angiology, Hugstetter Str 55, D-79106, Freiburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't