Objective

Cardiopulmonary exercise testing (CPT) is a powerful predictor for adverse events in congestive heart failure. The prevalence and significance of exercise intolerance in operated congenital heart disease merits investigation. This study was done to compare cardiopulmonary exercise parameters in patients after surgical repair of Tetralogy of Fallot (rTOF) with operated Atrial Septal Defect (ASD) and normal controls.
Method
23 patients aged >10 years (Group1,range 10 – 36 years, median 19.5 years) who had undergone surgical repair of TOF at a median age 10 years, underwent CPT using upright bicycle ergometry using MedGraphics BreezeSuite PFX UltimaTM till exhaustion. The results were compared with operated ASD patients (Group 2) and normal controls (Group3).

Results

Table 1 shows the group means of all exercise parameters. Though statistical significance was shown for only peakVO2 and MEP, other variables for rTOF also tended to have uniformly impaired values. Values crossing an arbitrary cut-off limit were almost confined to rTOF patients. rTOF patients with a combination of known markers of RV dysfunction (dilated RV, severe PR and prolonged QRS) were more likely to have impaired VO2max, VR and MEP (Figure 1).

Conclusion

rTOF patients frequently show impaired CPT parameters. This impairment is disease specific as operated ASD patients behaved like controls. RV dilatation, prolonged QRS duration and significant PR are more likely to be associated with impaired CPT parameters. The long term predictive value of these findings for adverse events needs prospective evaluation.