Left ventricular dysfunction on exercise long-term after total repair of tetralogy of Fallot

Excellent results regarding mortality are well recognized in the long-term period after intracardiac repair of tetralogy of Fallot. However, it is still unclear how postoperative sequelae affect cardiac performance during exercise.

Twenty-nine patients with tetralogy of Fallot were studied 16 +/- 2 years after intracardiac repair by use of radionuclide first-pass ventriculography with an ultra-high-sensitive gamma camera at rest and at peak exercise on a semi-upright bicycle ergometer. The results were compared with those from 10 age- and sex-matched control subjects. Left and right ventricular ejection fraction and absolute ventricular volume were measured at rest and peak exercise. Regional right ventricular wall motion and diastolic function of the left ventricle were also assessed. Cardiac output of tetralogy was normally preserved both at rest and during exercise. Nevertheless, the incremental response of left ventricular ejection fraction during exercise was depressed in the patients. Left ventricular ejection fraction during exercise was inversely correlated with the right ventricular end-diastolic volume and the severity of pulmonary regurgitation. Regional wall motion at the right ventricular outflow tract was not decreased in the patients. Left ventricular diastolic function was not impaired in the patients compared with control subjects.

Latent left ventricular dysfunction during exercise is related to an enlarged right ventricle due to pulmonary regurgitation after intracardiac repair of tetralogy. Careful follow-up is required in patients having significant pulmonary regurgitation.