Assessment of main hemodynamic parameters by transpulmonary thermodilution in children after complete repair of tetralogy of Fallot

Objectives. The objective of the study was to assess functional hemodynamic parameters in patients who underwent primary repair of tetralogy of Fallot by using transpulmonary thermodilution in early post-operative period. Materials and Methods. The prospective nonrandomized clinical study of 52 children (28 boys and 24 girls) after primary repair of tetralogy of Fallot was performed in the Novosibirsk Research Institute of Circulation Pathology n.a. acad. E.N. Meshalkin. Patients were divided into 2 groups based on the type of right ventricular (RV) outflow tract reconstruction. Group 1 comprised patients with transannular plasty (26 pts). Group 2 comprised patients in whom the pulmonary valve was preserved (II group, 26 pts). Both groups were comparable by the height, weight, body surface area, age, peak systolic RV outflow tract (RVOT) gradient, and ejection fraction of the left ventricle. Monitoring of the hemodynamic parameters was performed by using PiCCO (pulse-induced contour cardiac output), a method based on combination of the transpulmonary thermodilution and pulse waveform analysis. Results. During the first hours after operation, the signs of heart function were lower in group 1 and significantly differed with those in group 2. However, during the following hours (12, 24, 48 h), heart function recovered in the group 1 and did not differ from that in group 2. Afterload was elevated in both groups throughout the entire study. Afterload was significantly higher in group 1 for the first 24 h and in group 2 at 48 h. Conclusions. Preservation of RVOT components ensured significant improvement of the hemodynamic parameters including the indicators of systolic and diastolic functions in early post-operative period compared with patients who underwent transannular RVOT plasty. Residual RVOT obstruction with systolic pressure gradient of 37 mm Hg did not significantly affect the hemodynamic parameters.