[Functional capacity and rhythm changes after atrial correction of transposition of great arteries]

A group of 12 patients, previously submitted to atrial correction of the transposition of the great vessels, were studied through stress test with direct metabolimetry and Holter to assess aerobic functional capacity and its relationship with conduction disturbances. The results were compared with those obtained with a control group of 23 non athletic healthy children. All the patients showed amputation of their heart rates on effort, though this parameter and the oxygen consumption were normal at low work load levels. The VO2 at anaerobic threshold, the maximum VO2, and the maximum work load were also decreased in most of the patients. Holter studies demonstrated sick sinus syndrome in nine of them. Aerobic functional capacity was reduced in most of the patients with atrial correction of the transposition of the great vessels. The amputation of the heart rate on effort is a common finding though its relationship with the decrease of the aerobic functional capacity in these patients is limited. Finally, the stress test is probably more sensible than Holter for the detection of slight degrees of sinus disfunction.