Left ventricular (LV) systolic and diastolic function was assessed in 12 patients after total correction of tetralogy of Fallot (age range 5 to 18 years, mean 10) and compared with 10 control patients. Only 1 patient had a shunt before total correction that was performed at a mean age of 3.5 years, (range 0.3 to 8). At cardiac catheterization the following indexed LV parameters were measured: end-diastolic and end-systolic volumes, wall mass, ejection fraction, stroke volume and end-diastolic and end-systolic pressures and stresses. The rate-corrected mean velocity of fiber shortening was calculated. LV diastolic operant chamber stiffness and myocardial stiffness were calculated from simultaneous diastolic pressures and volumes in mid- and late diastole using monoexponential formulas. The 2 groups were compared by unpaired t tests. The tetralogy group had higher mean end-diastolic (93 vs 74 ml/m2), end-systolic (29 vs 19 ml/m2) and stroke (64 vs 55 ml/m2) volumes than controls. Rate-corrected mean velocity of fiber shortening was lower in the tetralogy group (1.07 vs 1.24). Myocardial stiffness was higher in the tetralogy group (16 vs 11). Other indexes were not significantly different. Thus, LV function after total correction of tetralogy of Fallot may be abnormal with larger than normal LV size, decreased contractile function and increased myocardial stiffness.