All 32 survivors with transposition of the great arteries, born in 1964-83 and operated on at our institution using atrial redirection, were evaluated by cardiac catheterization, echocardiography and Holter monitoring. There were 17 Mustard patients, age 17.1 years (+/-3.5, 12.0-22.0) and 15 Senning patients, age 9.4 years (+/-1.6, 7.2-12.1). All but one had simple transposition. Six had caval obstruction, one had pulmonary venous obstruction, three had large atrial shunts, four had considerable pulmonary hypertension, seven had mild ventricular outflow tract obstruction, four had significant tricuspid regurgitation, 11 had systemic ventricle dysfunction (one severe), 14 had sinus node dysfunction (three symptomatic) and two had atrioventricular block (one with pacemaker). Eight Mustard patients (47%) and one Senning patient (7%) had symptomatic cardiac sequelae, and only one patient (Senning) was free from sequelae, illustrating that these patient groups will need continuing medical attention.