The Heart Centre for Children, The Children's Hospital at Westmead, Corner of Hawkesbury Road and Hainsworth Street, Westmead, New South Wales 2145, Australia.
Department of Cardiology, The Royal Prince Alfred Hospital, Missenden Road, Camperdown, New South Wales 2050, Australia.
Eur Heart J Cardiovasc Imaging. 2019 Sep 1;20(9):1020-1026. doi: 10.1093/ehjci/jez035.
Pulmonary regurgitation (PR) and right ventricular (RV) dilatation are common in repaired tetralogy of Fallot (rTOF). Left ventricular (LV) dysfunction is an important risk factor in rTOF. The effect of PR/RV dilatation on LV performance and RV-LV interactions in rTOF are incompletely understood. We examined LV responses and exercise capacity in rTOF, both before and after pulmonary valve replacement (PVR).
Cardiac magnetic resonance imaging scans in 126 rTOF patients (age 17.3 ± 7.6 years) were analysed, comparing subjects with indexed RV end-diastolic volume (RVEDVi) <170 mL/m2 (mild/moderate dilatation, n = 95) and RVEDVi ≥170 mL/m2 (severe dilatation, n = 31). Indexed PR volume (PRVi), RV end-systolic (RVESVi), RV end-diastolic (RVEDVi), RV stroke volume (RVSVi), net pulmonary forward flow (NPFFi), LV end-diastolic (LVEDVi), LV end-systolic (LVESVi), LV stroke volume (LVSVi), RV and LV ejection fraction (EF), and diastolic septal curvature were obtained. Peak aerobic capacity (VO2 max) was measured. In a subset (n = 30), measures were obtained pre-and-post surgical PVR. Compared to those with mild/moderate RV dilatation, patients with severe RV dilation had greater PRVi (38 ± 12 vs. 24 ± 9 mL/m2, P < 0.0001), NPFFi (53 ± 9 vs. 44 ± 11 mL/m2, P < 0.0001), LVEDVi (87 ± 14 vs. 73 ± 13 mL/m2, P < 0.0001), LVESVi (39 ± 12 vs. 30 ± 8 mL/m2, P < 0.0001), and LVSVi (48 ± 7 vs. 43 ± 8 mL/m2, P = 0.002) but lower RV ejection fraction (46 ± 8 vs. 53 ± 7%, P < 0.0001). Septal curvature and VO2 max were similar in both groups. After PVR, there was no change in LVEDVi, LVSVi, septal curvature, or VO2 max.
Chronic PR with severe RV dilatation is associated with increased NPFFi, LVEDVi, and LVSVi. This may potentially explain preserved exercise capacity in rTOF with severe PR and RV dilatation.
肺动脉瓣反流（PR）和右心室（RV）扩张在修复后的法洛四联症（rTOF）中很常见。左心室（LV）功能障碍是 rTOF 的一个重要危险因素。PR/RV 扩张对 rTOF 中 LV 功能和 RV-LV 相互作用的影响尚不完全清楚。我们研究了 rTOF 患者在接受肺动脉瓣置换（PVR）前后的 LV 反应和运动能力。
对 126 例 rTOF 患者（年龄 17.3±7.6 岁）的心脏磁共振成像扫描进行了分析，比较了指数化 RV 舒张末期容积（RVEDVi）<170mL/m2（轻度/中度扩张，n=95）和 RVEDVi≥170mL/m2（严重扩张，n=31）的患者。测量了指数化 PR 容积（PRVi）、RV 收缩末期（RVESVi）、RV 舒张末期（RVEDVi）、RV 每搏输出量（RVSVi）、净肺前向流量（NPFFi）、LV 舒张末期（LVEDVi）、LV 收缩末期（LVESVi）、LV 每搏输出量（LVSVi）、RV 和 LV 射血分数（EF）和舒张间隔曲率。测量了峰值有氧能力（VO2 max）。在一个亚组（n=30）中，在手术 PVR 前后获得了测量值。与轻度/中度 RV 扩张的患者相比，严重 RV 扩张的患者 PRVi（38±12 vs. 24±9mL/m2，P<0.0001）、NPFFi（53±9 vs. 44±11mL/m2，P<0.0001）、LVEDVi（87±14 vs. 73±13mL/m2，P<0.0001）、LVESVi（39±12 vs. 30±8mL/m2，P<0.0001）和 LVSVi（48±7 vs. 43±8mL/m2，P=0.002）更高，但 RV 射血分数（46±8 vs. 53±7%，P<0.0001）更低。两组间的间隔曲率和 VO2 max 相似。PVR 后，LVEDVi、LVSVi、间隔曲率和 VO2 max 均无变化。
慢性 PR 伴严重 RV 扩张与 NPFFi、LVEDVi 和 LVSVi 增加有关。这可能部分解释了严重 PR 和 RV 扩张的 rTOF 患者运动能力保存的原因。
