[The influence of nCPAP therapy on the autonomic nervous system dysfunction in OSA patients].
Obstructive sleep (OSA) can induce severe arrhythmias, including prolonged periods of asystole and heart block. Heart rate variability (HRV) has gained importance as a technique employed to explore the autonomic nervous system (ANS) which plays an important role in arrythmogenesis.


OBJECTIVE
Our aim was to investigate nocturnal HRV by spectral analysis of RR intervals before and after continuous positive airway pressure (nCPAP) therapy.


METHODS
To confirm the relation between OSA and ANS dysfunction, we prospectively investigated ANS function in 24 patients (18 males, mean age 53 years) with moderate or severe OSA. Overnight polysomnography was performed before and after nCPAP therapy. We analyzed apnea/hypopnea index (AHI), desaturation index, mean arterial oxygen saturation, mean and standard deviation (SD) for nocturnal HRV triangular index and pNN50 before and after initiating CPAP treatment.


RESULTS
AHI decreased markedly from 51 to 3 events/h, desaturation index decreased from 45.9 to 3.62 events/h, and mean arterial oxygen saturation improved from 92.15% to 94.8%. Nocturnal HRV triangular index decreased from 18.3 to 12.85 as well as nocturnal pNN50 in all patients after initiating nCPAP therapy, suggesting that efficient nCPAP therapy may restore nocturnal autonomic defects, characteristic of severe and moderate OSA, as proven in previous studies.


CONCLUSIONS
Abnormalities in cardiovascular variability may be implicated in the subsequent development of cardiovascular diseases in patients with OSA. These results suggest that impaired ANS function is present in patients with OSA and can be improved by successful nCPAP therapy.
Mucenica
Elena Corina
EC
Facultatea de Medicina, Spitalul Clinic Pneumologie Iaşi, Universitatea de Medicina si Farmacie "Gr.T. Popa" Iaşi,
Boişteanu
Daniela
D
Vasiloiu
Gabriela
G
Cernomaz
A
A
Asandei
Raluca
R
Wirth
J A
JA
D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D045422:Continuous Positive Airway Pressure / Q000379:methods; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011446:Prospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*