Published online before print June 12, 2006, doi: 10.1161/CIRCULATIONAHA.105.602748
(Circulation. 2006;113:2844-2850.)
© 2006 American Heart Association, Inc.
Pediatric Cardiology |
Evidence for Cardiovascular Autonomic Dysfunction in Neonates With Coarctation of the Aorta
From the Departments of Clinical Sciences at South Bristol (J.W.P., N.M., A.R.W.), Physiology (H.W., J.F.R.P.), and Medical Physics (G.T., M.A.T.), School of Medical Sciences, Bristol Heart Institute, University of Bristol, Bristol, United Kingdom.
Correspondence to Andrew R. Wolf, Paediatric Intensive Care Unit, Bristol Royal Hospital for Children, Upper Maudlin St, Bristol, B52 8BJ, United Kingdom. E-mail AWolfbch{at}aol.com
Received November 19, 2005; revision received March 13, 2006; accepted April 14, 2006.
Background— Coarctation of the aorta (CoA) is associated with hypertension and abnormalities of blood pressure control, which persist after late repair. Assumptions that neonatal repair would prevent development of blood pressure abnormalities have not been supported by recent data. We hypothesized that early pathological adjustment of autonomic cardiovascular function may already be established in the neonate with coarctation.
Methods and Results— We studied 8 otherwise well neonates with simple CoA and compared measures of spontaneous baroreflex sensitivity, heart rate variability, and blood pressure variability with 13 healthy newborn babies. Spontaneous baroreflex sensitivity was calculated with sequence methodology from an ECG, and noninvasive blood pressure was recorded with a Portapres. Heart rate variability was determined with time- and frequency-domain measures. Blood pressure variability was measured in the frequency domain. In comparison with normal controls, neonates with CoA had raised blood pressure (78.9±3.8 versus 67.1±2.1 mm Hg), depressed baroreflex sensitivity (8.7±1.5 versus 13.8±1.1 ms/mm Hg), reduced heart rate variability (total power 16.5±3.1 versus 31.5±2.2 ms2), and an increase in the high-frequency component of blood pressure variability (3.1±0.3 versus 2.2±0. 2 mm Hg2). This is not the pattern expected if neonates with CoA simply had subclinical cardiac failure.
Conclusions— These data suggest that infants with CoA already show signs of pathological adjustment of autonomic cardiovascular homeostasis. Further longitudinal studies are required to determine whether these alterations play a role in the increased risk of late hypertension in these patients.