Improvement in Left Ventricular Function after Pulmonary Valve Replacement in Patients with Tetralogy of Fallot

  • Dr David Tanous, Australia
  • Dr Jasmine Grewal, Toronto Congenital Cardiac Centre for Adults, Peter Munk Cardiac Centre, University Health Network/Toronto General Hospital, Canada
  • Dr Laura Dos Subira, Toronto Congenital Cardiac Centre for Adults, Peter Munk Cardiac Centre, University Health Network/Toronto General Hospital, Canada
  • Dr Christopher Calderone, Division of Cardiovascular Surgery, Hospital for Sick Children, Toronto, Canada
  • Dr Erwin Oechslin, Toronto Congenital Cardiac Centre for Adults, Peter Munk Cardiac Centre, University Health Network/Toronto General Hospital, Canada
  • Dr Candice Silversides, Toronto Congenital Cardiac Centre for Adults, Peter Munk Cardiac Centre, University Health Network/Toronto General Hospital, Canada

    • Background

    Left ventricular (LV) dysfunction can occur in patients with repaired tetralogy of Fallot (rTOF), due partly to adverse ventricular-ventricular interactions. The purpose of this study was to determine whether pulmonary valve implantation (PVR) and subsequent right ventricular (RV) remodelling, was associated with improvement in LV function.

    Methods

    Pre- and post-operative echocardiograms of consecutive patients with rTOF undergoing PVR between 2003 and 2008 at a single centre were reviewed. Exclusion criteria for patients included: a) inadequate echocardiographic images, b) not in sinus rhythm at either examination, c) predominant pulmonary stenosis, d) undergoing concomitant tricuspid, aortic or mitral valve surgery. Global RV and LV function was measured using the myocardial performance index (MPI) and LV volumes using the area-length method. Comparisons between pre- and post-operative data were made using Wilcoxon signed-rank test.

    Results

    Twenty-four patients (mean age 32±10 years) were included. Mean age at intra-cardiac repair (transannular patch in 75%) was 6±3 years. The RV end-diastolic diameter decreased from 52±7 mm pre-operatively to 43±9 mm post-operatively (p<0.001). Global RV (RV MPI 0.28±0.11 vs. 0.23±0.12, p=0.03) and LV (LV MPI 0.49±0.17 vs. 0.42±0.15, p=0.04) function improved after surgery. The LV end-diastolic volume increased (101±39 vs. 114±35 mL, p=0.03), but LV end-systolic volume was unchanged (47±22 vs. 48±17 mL, p=0.47) with a resultant increase in LV ejection fraction (54±6% vs. 58±6%, p=0.02).

    Conclusions

    In patients with rTOF, global LV function shows improvement after PVR. Improvements in ventricular-ventricular interactions, as a result of reduction in RV size, are a possible explanation for this finding.