Exercise capacity in young patients after total repair of Tetralogy of Fallot

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. Measurement of physical activity is usually performed as a routine part of the patient's cardiac evaluation. The aim of this study was to examine the exercise performance of young patients operated on for tetralogy of Fallot, assessing the possible influence of known negative prognostic factors related to the surgical repair. The study group comprised 41 consecutive patients (29 male and 12 female, ages 11.2 ± 3.9 years, range 6- 16 years) operated on for tetralogy of Fallot. Patients in the study group were divided in subgroups in relation to the age of surgical intervention (before or after 2 years of life), the surgical approach (combined transatrial/transpulmonary approach or right ventriculotomy), and the presence of aortopulmonary shunts prior to performing total correction. Their data were compared with those of 33 aged-matched asymptomatic control subjects (19 male and 14 female, ages 11.9 ± 1.3 years, range 11-16 years). Blood pressure and heart rate measured at rest were similar between control and Fallot groups. A normal increase in systolic blood pressure was observed in response to exercise intensity for all subgroups. No significant difference between control and Fallot groups was found under conditions of mild or moderate exercise or for diastolic blood pressure at rest and in response to exercise. Lower maximal heart rate and systolic blood pressure values were recorded in all patients when compared with the control subjects. Significant differences in peak workload were detected between control and Fallot groups and between the control and each subgroup; however, no difference was found between subgroups. In conclusion, despite their very satisfactory clinical status, all patients showed a reduced peak workload, irrespective of the surgical approach, age at surgery, and aortopulmonary shunts prior to performing total correction.