Hemodynamics and Exercise Tolerance after Senning Operation for Transposition of Great Arteries and Its Limiting Factors: A Longitudinal Study
Abstract
Objectives: The purpose of this longitudinal study was to assess hemodynamics and exercise capacity in patients after Senning operation and to determine its limiting factors. Methods: 87 long-term survivors of the Senning operation for transposition of great arteries were recruited for a longitudinal follow-up study consisting of two cross-sectional evaluations at a mean of 12.6 and 22.6 years after surgery, respectively.
The protocol included a questionnaire, echocardiography, radionuclide angiocardiography, magnetic resonance imaging and cardiopulmonary exercise test. Decreased exercise capacity was defined as maximum oxygen uptake <-2 Z-scores.
Results: Hemodynamic variables (right ventricular function and degree of tricuspid regurgitation) and chronotropic competence did not change significantly with time. Decreased exercise tolerance was present in 55.6 and 49.3% of patients at the first and second evaluation, respectively (NS) and had multi-variable correlation with lower right ventricular end-diastolic volume (P=0.039, OR 0.963) and increased ventilation/carbon dioxide production slope (P=0.040, OR 1.293).
None of other hemodynamic variables correlated with decreased functional capacity. Conclusions: Long-term survivors of the Senning operation have stable hemodynamics and exercise capacity on longitudinal follow-up.
Decreased exercise tolerance is found in approximately half of the patients and is significantly associated with lower ventilation efficiency. This data may point to the usefulness of targeted respiratory rehabilitation in this patient group.