Implications of Restrictive Right Ventricular Physiology in Right Ventricular Adaptation to Chronic Pulmonary Regurgitation in Patients with Repaired Tetralogy of Fallot: Assessment with Cardiovascular Magnetic Resonance and Tissue Doppler Imaging

  • Dr Chun-An Chen, Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, Taiwan
  • Dr Wen-Yih Tseng, Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, Taiwan
  • Prof Jou-Kou Wang, National Taiwan University Hospital, Taiwan
  • Dr Chung-I Chang, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Taiwan
  • Dr Ing-Sh Chiu, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Taiwan
  • Dr Yih-Sharng Chen, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Taiwan
  • Dr Hsi-Yu Yu, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Taiwan
  • Dr Mei-Hwan Wu, Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, Taiwan

    • Objectives. To explore the role of restrictive right ventricular (RV) physiology (antegrade pulmonary arterial flow in late diastole) in RV adaptation to pulmonary regurgitation (PR) in repaired tetralogy of Fallot.

    Methods. We studied 80 patients (aged 22.7 ± 7.8 years) without significant residual pulmonary stenosis using cardiovascular magnetic resonance and tissue Doppler imaging. Restrictive RV physiology was assessed by Doppler echocardiography.

    Results. Patients with restrictive RV physiology (32 patients, 40%) had lower PR fraction (PRF), RV end-diastolic volume index (RVEDVi), myocardial performance index (MPI), higher late diastolic annular velocity, less RV outflow tract aneurysm and transannular patch (TAP) than those without (Table). Age at repair (OR: 0.61, P = 0.042), TAP (OR: 0.20, P = 0.031), RVEDVi (OR: 0.93, P = 0.001), and MPI (OR: 0.001, P = 0.027) were independently associated with restrictive RV physiology on multivariate analysis. Furthermore, PRF correlated negatively with RV ejection fraction (RVEF) in patients without restrictive RV physiology, whereas such relationship was absent in those with restrictive RV physiology, either in overall patients (Figure) or in those with PRF > 20% (55 patients). Subgroup analysis in patients with PRF > 20% revealed smaller RVEDVi (111.7 ± 14.8 versus 139.2 ± 34.2 ml/m2, P < 0.001) and better RVEF (51.2 ± 5.5 versus 46.8 ± 9.2 %, P = 0.042) in patients with restrictive RV physiology (13 patients) than those without despite similar PRF.

    Conclusions. Patients with restrictive RV physiology had better RV performance, probably through mitigating the detrimental effect of PR on RV remodeling.

    Variables All (n=80) With restrictive RV physiology (n=32) Without restrictive RV physiology (n=48) P value
    TAP repair 38/73 (52%) 9/30 (30%) 29/43 (67%) 0.001
    QRS duration (ms) 147.8 ± 20.3 139.2 ± 18.3 153.5 ± 19.8 0.002
    RV MPI 0.49 ± 0.11 0.46 ± 0.10 0.51 ± 0.11 0.030
    Aa (cm/s) 7.9 ± 2.8 8.8 ± 3.0 7.4 ± 2.6 0.029
    RVEDVi (ml/m2) 119.5 ± 35.2 96.9 ± 20.9 134.5 ± 34.9 < 0.001
    RVESVi (ml/m2) 63.1 ± 26.6 48.6 ± 14.1 72.8 ± 28.6 < 0.001
    PRF (%) 28.8 ± 17.3 18.3 ± 15.5 35.8 ± 14.7 < 0.001
    RV outflow tract aneurysm 17 (21%) 1 (3%) 16 (33%) 0.002