Alteration of QT rate dependence reflects cardiac autonomic imbalance in patients with obstructive sleep apnea syndrome.
Pacing Clin Electrophysiol
; 26(7 Pt 1): 1446-53, 2003 Jul.
Article
en En
| MEDLINE
| ID: mdl-12914620
QT rate dependence is one of the major properties of ventricular repolarization with its circadian and autonomic modulations. The authors postulated that dynamic alterations in QT interval adaptation could help characterize patients with cardiac autonomic alterations, like those with obstructive sleep apnea syndrome (OSAS). To assess ventricular repolarization features in patients with OSAS, QT parameters and their dynamicity along RR intervals were compared from 24-hour ECG data of patients with and without this syndrome, assessing cardiac autonomic nervous system equilibrium by means of time-domain and frequency-domain analyses of heart rate variability (HRV). The study group consisted of 74 consecutive patients referred to the Sleep Laboratory for clinically suspected OSAS. The syndrome was confirmed in 30 (40.5%) patients according to standard polysomnographic criteria. QT length related to heart rate (HR) was found significantly shorter for HR < 70 beats/min in patients with OSAS(-1.32 +/- 0.35)compared with patients without OSAS(-1.99 +/- 0.40; P < 0.01). This flattened relationship was correlated with the severity of the sleep related disorder. Using multiple linear regression analysis, the apnea/hypopnea index and nocturnal normalized high frequencies (HFnu) were the most significant predictors of the QT/RR slope(R = 0.61; P < 0.0001). OSAS is significantly associated with a flattened relationship between QT duration and RR interval at low HRs. The alteration of cardiac parasympathetic tone occurring in severe OSAS patients may explain this altered rate dependent adaptation of myocardial repolarization.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Sistema Nervioso Autónomo
/
Apnea Obstructiva del Sueño
/
Electrocardiografía
/
Corazón
Tipo de estudio:
Prognostic_studies
Límite:
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Pacing Clin Electrophysiol
Año:
2003
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Estados Unidos