Cardiorespiratory response to exercise in Ebstein's anomaly.

Fourteen patients with unrepaired Ebstein's anomaly underwent maximal exercise testing between October 1982 and April 1984. Compared with control subjects, these patients had significantly lower values for total work performed, exercise time, maximal oxygen uptake, blood oxygen saturation at rest and during exercise, and heart rate and systolic blood pressure during maximal exercise. They had a significant increase in heart rate at rest. The ventilatory equivalent for oxygen was increased significantly both at rest and during exercise. Thus, patients with Ebstein's anomaly have decreased exercise tolerance owing to both cardiac and respiratory limitations.