High
Accuracy of Automatic Detection of Atrial Fibrillation Using Wavelet
Transform of Heart Rate Intervals.
David Duvernet, Jean-Michel Gaspoz, Vincent Pichot, Frédéric
Roche, Richard Brion, Anestis Antoniadis, and Jean-Claude Barthélémy.
Duverney,
D., et Al.: Accuracy of Automatic Detection of Atrial Fibrillation
Using Wavelet Transform of Heart Rate Intervals.
Permanent and paroxysmal AF is a risk factor
for the occurrence and the recurrence of stroke, which can occur
as
its first manifestation. Howewer, its automatic identification is
still unsatisfactory. In this study, a new mathematical approach
was
evaluated to automate AF identification. A derivation set of 30 24-hour
Holter recordings, 15 with chronic AF (CAF) and 15 with sinus rhythm
(SR), allowed the authors to establish specific RR variability characteristics
using wavelet and fractal analysis. Then, a validation set of 50
subjects
was studied using these criteria, 19 with CAF, 16 with SR, and 15
with paroxysmal AF (PAF); and each QRS was classified as true or
false
sinus or AF beat. In the SR group, specificity reached 99.9%; in
the CAF group, sensitivity reached 99.2%; in the PAF group, sensitivity
reached 96.1%, and specificity 92.6%. However, classification on
a patient basis provided a sensitivity of 100%. This new approach
showed a high sensitivity and a high
specificity
for automatic AF detection, and could be used in screening for AF
in large populations at risk. (PACE 2002; 25[Pt. I]:457-462)
Keywords: arrhythmia,
automatic atrial fibrillation detection, Holter system, time frequency
analysis, fractional brownian motion.
PACE, Vol. 25,
No. 4, April 2002, Part I
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Frequent
and Prolonged Asymptomatic Episodes of Paroxysmal Atrial Fibrillation
Revealed by Automatic Long-Term Event Recorders in Patients with a Negative
24-Hour Holter.
Frédéric Roche, Jean-Michel Gaspoz, Antoine Ad
Costa, Karl Isaaz, David Duverney, Vincent Pichot, Frederic Costes,
Jean-René Lacour and Jean-Claude Barthélémy.
Roche, F., et Al.: Frequent and Prolonged Asymptomatic Episodes
of Paroxysmal Atrial Fibrillation Revealed by Automatic Long-Term Event
Recorders in Patients with a Negative 24-Hour Holter.
The presence, frequency, and duration of episodes of paroxysmal atrial
fibrillation (PAF) is difficult to establish. This is caused by the
limited duration of standard Holter recordings and to the unsatisfactory
yield of patient-triggered event recorders, because of asymptomatic
events and of an inconsistent use of the patient dependent triggering
function. A prospective cohort of 65 consecutive patients with recurrent
palpitations and a negative 24-hour ECG Holter was investigated by means
of a cardiac event recorder bearing continuous automatic arrhythmia
analysis and storage. Over a mean duration of 77 +/- 36 hours, episodes
of PAF were diagnosed in 20 (31%) patients, who had a total of 37 episodes;
mean duration of PAF episodes was 7 hours 50 minutes +/- 8/hours 45
minutes (minimum 45 minutes, maximum 28 hours). Eleven (55%) of these
20 patients were asymptomatic and would have remained undiagnosed without
the automatic mode of the event recorder. Asymptomatic PAF episodes
were longer than symptomatic ones (10 hours 30 minutes +/-6 hours 30
minutes vs 4 hours 50 minutes +/-4 hours, P<0.05). In addition, episodes
of sustained paroxysmal supraventicular tachycardia (PSVT) were diagnosed
in 39 (57%) patients, of whom 34 (87%) were symptomatic. In this prospective
cohort, a second standard 24-hour monitoring would have missed 44% of
the patients with PAF or PSVT and a classical patient-triggered event
recorder 13%. In patients still complaining of palpitations after one
negative 24-hour Holter, numerous, prolonged, and often asymptomatic
episodes of PAF can be revealed by long-term automatic event recorders.
These devices should help clarify the clinical consequences of such
episodes. (PACE 2002; 25:1587-1593)
Keywords:
paroxysmal atrial fibrillation, arrhythmia detection, automatic cardiac
event recorder.
PACE
2002; 25, No. 11, November 2002
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Prevention
of Atrial Fibrillation by Complete Compartmentalization of the Lef Atrium
Using a Catheter Technique
Sabine
ERNST, M.D., Feifan OUYANG, M.D., Birke SCHNEIDER, M.D, and Karl-Heinz
KUCK, M.D.
From Allgemeines Krankenhaus St. Georg, Hamburg, Germany.
LA Compartmentalization for AF Prevention.
Introdution
Right atrial compartmentalization has been demonstrated to only reduce
the number of atrial fibrillation (AF) episodes; left atrial 'LA) fibrillation
still occurs.
Methods and Results
We report successful LA compartmentalization resulting in isolation
of all four pulmonary veins in a 51-year-old woman suffering from paroxysmal
AF. Deployment of a complete encircling line resulted in dissociation
of electrical activation within the isolated area from the remaining
LA. Despite attempts at reinduction by pacing maneuvers inside and outside
the isolated area, AF was no longer inducible.
During 21-week follow-up, the patient was completely free of symptoms.
Antiarrhythmic therapy with sotatol (as before the last ablation) was
continued during the initial 12 weeks of follow-up and then discontinued.
Sequential Holter recordings showed stable sinus rhythm with rare atrial
extrasystoles.
Using a continuous 7-day event recorder (R.TEST Evolution, NOVACOR,
Rueil-Malmaison, France) stable sinus rhythm was documented without
evidence of asymptomatic episodes of AF.
Conclusion
If reproductible, this ablation strategy could allow treatment of AF
independent of suppression of any triggering event.
J Cardiovasc
Electrophysiol,
Vol 11, pp 686-690, June 2000
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Automatic
Cardiac Event Recorders Reveal Paroxysmal Atrial Fibrillation
after Unexplained Strokes or Transient Ischemic Attacks
Jean-Claude Barthélémy, M.D., Ph. D., * Séverine
Féasson-Gérard, M.D., * Pierre Garnier, M.D., ** Jean-Michel
Gaspoz, M.D., M.S.c., *** Antoine Da Costa, M.D., **** Daniel Michel, M.D.,
Ph.D., ** and Frédéric Roche, M.D., Ph.D. *
From
the * Service d'Exploration Fonctionnelle CardioRespiratoire, Laboratoire
de Physiologie, CHU Nord, France; ** Service de Neurologie, CHU
Bellevue, Faculté de Médecine Jacques Lisfranc, Université Jean
Monnet, France; *** Clinique de Médecine II et Division
de Cardiologie, Département de Médecine Interne,
Hôpitaux Universitaires, Switzerland; * Service de Cardiologie,
CHU Nord, Faculté de Médecine Jacques Lisfranc, Université Jean
Monnet, France.
Background
The etiology of stroke or transitory ischemic attack (TIA) remains frequently
unknown. While paroxysmal atrial fibrillation (PAF) is often suspected,
its presence remains difficult to establish. Therefore, we investigated
the occurence of PAF episodes in such a population using a long-term automatic
cardiac event recorder.
Method
We prospectively investigated 60 consecutives subjects admitted in our university
hospital for stroke (n=44) or TIA (n=16), adding long-term automatic cardiac
event recorders, with a target duration of 4 days, to standard investigations,
which included 12-lead ECGs and 24-hour Holter recordings.
Results
In 28 patients no etiology was found for their stroke or TIA. Howewer, one
or more than one PAF episode was found in 4 of them (14.3%) using the long-term
automatic event recorder. In the 32 remaining patients, 8 presented with
PAF, and this was considered as the cause of their stroke. In both groups,
AF was paroxysmal. The PAF episodes' duration went from 1 to 96 hours (mean
+- standard deviation, 18 hours and 30 minutes +- 30 hours).
Conclusions
Patients suffering PAF episodes after ischemic stroke or TIA were statistically
less often recognized using the 24-hour Holter ECG recording alone than
the R.TEST Evolution alone.
A.N.E.
2003; 8(3):194-199
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Usefulness of Ambulatory 7-Day ECG Monitoring for the Detection of Atrial Fibrillation and Flutter After Acute Stroke and Transient Ischemic Attack
Denis Jabaudon, MD, PhD; Juan Sztajzel, MD; Katia Sievert; Theodor Landis, MD; Roman Sztajzel, MD
From the Department of Neurology (D.J, T.L, R.S.) and Cardiology Center, Department of Internal Medicine, (J.S., K.S.), University Hospital Geneva, Geneva, Switzerland.
Correspondence to Denis Jabaudon, Department of Neurology, University Hospital Geneva, Rue Micheli-du-Crest 24, 1211 Genève 4, Switzerland. Email denis.jabaudon@hcuge.ch
Background and Purpose
Although atrial fibrillation is the most frequent cause of cardioembolic stroke, this arrhythmia remains underdiagnosed, as it is often asymptomatic or intermittent and, thus, may not be detected on standard 12-lead ECG or even 24-hour ECG recording (Holter). In this study, we hypothesized that 7-day ambulatory ECG monitoring using an event-loop recording (ELR) device would detect otherwise occult episodes atrial fibrillation and flutter (AF) after acute stroke or transient ischemic attack (TIA).
Methods
One hundred forty-nine consecutive patients admitted to our neurology department with an acute stroke or TIA were systematically screened for emboligenic arrhythmias using standard ECG. In the absence of AF on standard ECG, patients underwent 24-hour ECG recording (Holter), which was followed by a 7-day ambulatory ECG monitoring (ELR) in patients with a normal Holter. Patients with previously documented persistent AF, with primary hemorrhagic stroke, or with acute large vessel dissection were not included in the study.
Results
AF was detected in 22 patients. Standard ECG identified AF in 2.7% of the cases at admission (4/149 patients) and in 4.1% of remaining patients within 5 days (6/145). Holter disclosed AF in 5% of patients with a normal standard ECG (7/139 patients), whereas ELR detected AF in 5.7% of patients with a normal standard ECG and normal Holter (5/88 patients).
Conclusions
Following acute stroke or TIA, ELR identified patients with AF, which remained undetected with standard ECG and with Holter. ELR should, therefore, be considered in every patient in whom a cardioembolic mechanism is suspected.
Key Words
atrial fibrillation, diagnostic tests, electrocardiography, prevention and control, stroke, cardioembolic
Stroke, 2004, 35: 1647 - 1651
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