[Cardiac arrhythmia following total correction of tetralogy of Fallot]

41 patients after surgical correction of the tetralogy of Fall of aged 2-24 years (mean 11.2 y.) were followed for 12-65 months (mean 39.5 m.) for known or suspected dysrhythmias. 24-hour ambulatory ECG and exercise testing demonstrated nonsignificant ventricular ectopy (grade 0-1 according to a modified Lown classification) in 28 patients (group I) and significant (grade 2-5) ventricular dysrhythmias in the remaining 13 patients (group II). There were 2 cases of sudden late death in group II, whereas all patients in group I are alive. The victims of sudden death had no, other serious dysrhythmias and received no antiarrhythmic treatment. Ejection fraction of the functional part of the right ventricle estimated by radionuclide angiocardiography was not different in both groups whereas, global right ventricular ejection fraction differed nearly significantly (group I: 39.6 +/- 8.3%, group II: 31.9 +/- 10.4%, p = 0.052). Thus, a diminished global right ventricular ejection fraction caused by an extensive resection and large patch in the right ventricular outflow tract may be connected with the occurrence of higher grades of ventricular ectopy. These may lead to sudden late death.