Safety threshold of R-wave amplitudes in patients with implantable cardioverter defibrillator.
Heart
; 102(20): 1662-70, 2016 10 15.
Article
de En
| MEDLINE
| ID: mdl-27296239
ABSTRACT
OBJECTIVE:
A safety threshold for baseline rhythm R-wave amplitudes during follow-up of implantable cardioverter defibrillators (ICD) has not been established. We aimed to analyse the amplitude distribution and undersensing rate during spontaneous episodes of ventricular fibrillation (VF), and define a safety amplitude threshold for baseline R-waves.METHODS:
Data were obtained from an observational multicentre registry conducted at 48 centres in Spain. Baseline R-wave amplitudes and VF events were prospectively registered by remote monitoring. Signal processing algorithms were used to compare amplitudes of baseline R-waves with VF R-waves. All undersensed R-waves after the blanking period (120â ms) were manually marked.RESULTS:
We studied 2507 patients from August 2011 to September 2014, which yielded 229 VF episodes (cycle length 189.6±29.1â ms) from 83 patients that were suitable for R-wave comparisons (follow-up 2.7±2.6â years). The majority (77.6%) of VF R-waves (n=13953) showed lower amplitudes than the reference baseline R-wave. The decrease in VF amplitude was progressively attenuated among subgroups of baseline R-wave amplitude (≥17; ≥12 to <17; ≥7 to <12; ≥2.2 to <7â mV) from the highest to the lowest median deviations -51.2% to +22.4%, respectively (p=0.027). There were no significant differences in undersensing rates of VF R-waves among subgroups. Both the normalised histogram distribution and the undersensing risk function obtained from the ≥2.2 to <7â mV subgroup enabled the prediction that baseline R-wave amplitudes ≤2.5â mV (interquartile range 2.3-2.8â mV) may lead to ≥25% of undersensed VF R-waves.CONCLUSIONS:
Baseline R-wave amplitudes ≤2.5â mV during follow-up of patients with ICDs may lead to high risk of delayed detection of VF. TRIAL REGISTRATION NUMBER NCT01561144; results.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Fibrillation ventriculaire
/
Défibrillation
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Défibrillateurs implantables
/
Système de conduction du coeur
Type d'étude:
Clinical_trials
/
Diagnostic_studies
/
Etiology_studies
/
Observational_studies
/
Prognostic_studies
Limites:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Pays/Région comme sujet:
Europa
Langue:
En
Journal:
Heart
Sujet du journal:
CARDIOLOGIA
Année:
2016
Type de document:
Article
Pays d'affiliation:
Espagne