New evidence of baroreflex dysfunction in congenital central hypoventilation syndrome.

In this issue of Clinical Science, Trang and co-workers report the results of short-term blood pressure and heart rate variability measurements in patients with congenital central hypoventilation syndrome (CCHS). The results reveal that these young patients disclose signs of vagal withdrawal and baroreflex failure. Baroreflex sensitivity was reduced by one third compared with the matched control subjects; however, patients have a relative preservation of the cardiac and vascular sympathetic function. These findings are clearly new and improve our understanding of CCHS physiopathology. Nevertheless, more research is needed to better delineate the respective contribution of cardiac vagal and sympathetic dysregulation, and the extent to which these abnormalities relate to genetic mutations as well as to clinical status.