Children and adolescents with CHD have lower VO2max and HR compared to controls
BACKGROUND Children and adolescents with congenital heart disease often have alterations in their exercise capacity that can be evaluated by various functional testing .
OBJECTIVE To evaluate the functional capacity of children and adolescents with congenital heart disease ( CHD ) with systematic review and meta-analyses .
Severely Impaired Cardiac Autonomic Nervous Activity After the Fontan Operation
Background —Elevated neurohumoral activity and an abnormal cardiopulmonary response to exercise are well-established characteristics in patients after the Fontan operation .  However , there have been few studies addressing cardiac autonomic nervous activity ( CANA ) in these patients . Methods and Results —We evaluated CANA in 63 post-Fontan patients and 44 controls . Cardiac parasympathetic nervous activity ( PSNA ) was estimated by heart rate ( HR ) changes after cholinergic blockade , HR variability , and arterial baroreflex sensitivity . Cardiac sympathetic nervous activity was estimated by the heart to mediastinum [123I]metaiodobenzylguanidine activity ratio ( H/M ) and the HR increase ( & Dgr;HR ) after isoproterenol infusion ( & bgr ; ) . & Dgr;HR and peak oxygen uptake ( & OV0312;o2 ) were measured by exercise test . There was no difference in & bgr ; between the Fontan group and controls . PSNA and H/M were markedly lower than in controls ( P < 0.001 ) . PSNA and & bgr ; were related to & Dgr;HR ( P < 0.05 ) ; however , peak & OV0312;o2 was not correlated with & Dgr;HR . Neither PSNA nor H/M was associated with clinical features , including hemodynamics , type of repair , number of surgical procedures , age at Fontan operation , or follow-up period , and administration of an angiotensin-converting enzyme inhibitor did not improve the impaired CANA in these patients . Conclusions —After the Fontan procedure , postsynaptic & bgr;-sensitivity is maintained and is important in & Dgr;HR during exercise as is PSNA , although & Dgr;HR does not determine exercise capacity . The lack of a relationship between CANA and clinical features implies that , in addition to surgical damage , the Fontan circulation per se may impair CANA . Angiotensin-converting enzyme inhibitor administration does not change this abnormality
Children and adolescents with CHD have lower VO2max and HR compared to controls
BACKGROUND Children and adolescents with congenital heart disease often have alterations in their exercise capacity that can be evaluated by various functional testing .
OBJECTIVE To evaluate the functional capacity of children and adolescents with congenital heart disease ( CHD ) with systematic review and meta-analyses .