Exercise physiology and testing in adult patients with congenital heart disease.

As the longevity of patients with congenital heart disease improves, the number surviving to adulthood will continue to rise. Consequently, practicing physicians can expect to encounter an increasing number of adult patients with various congenital cardiac conditions. Impaired exercise tolerance in this patient population is exceptionally common; adult patients with congenital heart disease have reduced exercise capacity compared with healthy, age-matched counterparts. The different methods of evaluating exercise capacity, the characteristic physiologic abnormalities encountered in patients with various congenital cardiac conditions, the pathophysiologic mechanisms that may account for these abnormalities, and the clinical implications of these findings are discussed.