Aims: To identify factors predisposing to abnormal left ventricular geometry and mechanics in 52 patients after successful repair of aortic coarctation. Methods and results: We evaluated left ventricular remodelling, systolic midwall mechanics, and isthmic gradient by echo-Doppler, systemic blood pressure at rest/exercise and by ambulatory blood pressure monitoring, and the aortic arch by magnetic resonance imaging. Echocardiographic findings were compared with those of 142 controls. The patients with aortic coarctation showed an increased indexed left ventricular end-diastolic volume, increased mass index, increased ratio of mass to volume and systolic chamber function. The contractility, estimated at midwall level, was increased in 21 percent of the patients. In 26 (50 percent) of the patients, we found abnormal left ventricular geometry, with 9 percent showing concentric remodelling, 33 percent eccentric hypertrophy, and 8 percent concentric hypertrophy. These patients were found to be older, underwent a later surgical repair, and to have higher systolic blood pressures at rest and exercise as well as during ambulatory monitoring. The relative mural thickness and mass index of the left ventricle showed a significant correlation with different variables on uni- and multivariate analysis. Age and diastolic blood pressure at rest are the only factors associated with abnormal left ventricular remodelling. Conclusions: Patients who have undergone a seemingly successful surgical repair of aortic coarctation may have persistently abnormal geometry with a hyperdynamic state of the left ventricle. This is more frequent in older patients, and in those with higher diastolic blood pressures.