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Tachycardia in adults with cystic fibrosis is associated with normal autonomic function
Author(s) -
Szollosi I.,
King S. J.,
Wilson J. W.,
Naughton M. T.
Publication year - 2011
Publication title -
internal medicine journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.596
H-Index - 70
eISSN - 1445-5994
pISSN - 1444-0903
DOI - 10.1111/j.1445-5994.2009.02039.x
Subject(s) - medicine , heart rate variability , cardiology , cystic fibrosis , diaphragmatic breathing , tachycardia , autonomic nervous system , autonomic function , heart rate , diabetes mellitus , anesthesia , endocrinology , blood pressure , pathology , alternative medicine
Background: Whether autonomic dysfunction contributes to tachycardia in cystic fibrosis (CF) is unknown. Methods: Heart rate variability (HRV) was assessed to determine high frequency power and the low/high frequency power ratio (HF, LF/HF) as markers of vagal and sympathovagal balance, respectively, under spontaneous and controlled breathing (15 breaths per minute (bpm)) conditions in 17 CF and 17 healthy control subjects. Results: Under spontaneously breathing conditions, the CF group was tachycardic (75.4 ±11.2 vs 60.2 ±9.0 br/min P < 0.001) and tachypnoeic (22.6 ±5.8 vs 13.6 ±4.1 br/min, P = 0.001) compared with controls. No significant difference in HRV was observed between groups during spontaneous or controlled breathing. Coexistent diabetes mellitus and β 2 agonist use were not associated with altered autonomic control. During controlled breathing, the CF group showed a negative correlation between forced expiratory volume in 1 s (FEV 1 ) % predicted and HF power ( P = 0.013, r =−0.59) and a positive correlation between FEV 1 % predicted and LF/HF ratio ( P = 0.002, r = 0.69) suggesting an exaggerated normal vagal response. Conclusion: CF patients have normal autonomic function.