Enhanced stress reactivity in paediatric anxiety disorders: implications for future cardiovascular health

The aim was to clarify the developmental nature of associations between psy chiatric illness and risk for cardiovascular disease by investigating diffe rences in cardiac functioning between youth with anxiety disorders and heal thy controls. Twenty-two children meeting DSM-IV criteria for either separa tion anxiety disorder, overanxious disorder. panic disorder/panic attacks. or social phobia and 12 healthy controls underwent continuous electrocardio gram and respiration rate monitoring during a 15 min baseline period and 15 min of exposure to 5 % CO2. Heart rate (HR) and high frequency heart rate variability (HRV), a non-invasive measure of cardiac parasympathetic contro l, were calculated. Youth with anxiety disorders had higher and less fluctu ating HR during baseline. Data also suggested that probands showed diminish ed overall changes in HRV during baseline and CO2 inhalation relative to co ntrols. However, as respiration rate affects HRV, these findings were confo unded by changes in respiration elicited by CO2 inhalation. The data sugges t that youth with anxiety disorders experience an elevated and less fluctua ting HX in the face of a novel situation, possibly due to a failure to appr opriately modulate HRV. In adults, sustained elevations in HR in conjunctio n with deficient vagal modulation predicts risk for future cardiovascular d isease. As such, the current data suggest that the presence of an anxiety d isorder may identify youth who exhibit autonomic profiles that place them a t risk for cardiac disease.