Kang I-Seok, Redington Andrew N, Benson Leland N, Macgowan Christopher, Valsangiacomo Emanuela R, Roman Kevin, Kellenberger Christian J, Yoo Shi-Joon
Department of Diagnostic Imaging, The University of Toronto School of Medicine, Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8.
Circulation. 2003 Jun 17;107(23):2938-43. doi: 10.1161/01.CIR.0000077064.67790.5B. Epub 2003 May 27.
The importance of pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) is increasingly recognized, but little is known regarding its underlying mechanisms. This phase-contrast cine magnetic resonance (PC MR) study was performed to evaluate the relative contribution of each lung to total regurgitant volume.
Twenty-two patients with significant PR underwent a PC MR 3 to 16 years after repair of TOF. Regurgitant fraction of the main pulmonary artery was 39+/-10%. Regurgitant fraction of the left pulmonary artery (LPA; 46+/-18%) was greater than that of the right pulmonary artery (34+/-16%; P=0.002). The average contribution of the LPA to the total regurgitant flow volume was 54+/-19%, whereas its average contribution to the total forward flow volume was 44+/-13% (P=0.002). In 4 patients, regurgitant flow in the LPA accounted for 75% to 100% of the total regurgitant flow. There was a linear relationship between regurgitant fraction and fraction of the regurgitant flow duration in the main pulmonary artery (P<0.001) and right pulmonary artery (P=0.001) but not in the LPA (P=0.129).
PR after repair of TOF is commonly associated with differential regurgitation in the branch pulmonary arteries, which is usually greater in the LPA. Although the cause of this disparity requires further investigation, those patients with a significant unilateral contribution to total PR may be amenable to localized techniques to reduce regurgitation.
法洛四联症（TOF）修复术后肺动脉反流（PR）的重要性日益受到认可，但其潜在机制仍知之甚少。本相位对比电影磁共振（PC MR）研究旨在评估各肺对总反流容积的相对贡献。
22例有明显PR的患者在TOF修复术后3至16年接受了PC MR检查。主肺动脉的反流分数为39±10%。左肺动脉（LPA）的反流分数（46±18%）高于右肺动脉（34±16%；P = 0.002）。LPA对总反流流量的平均贡献为54±19%，而其对总前向流量的平均贡献为44±13%（P = 0.002）。在4例患者中，LPA的反流流量占总反流流量的75%至100%。主肺动脉（P < 0.001）和右肺动脉（P = 0.001）的反流分数与反流持续时间分数之间存在线性关系，但LPA中不存在（P = 0.129）。
TOF修复术后的PR通常与分支肺动脉的差异性反流有关，LPA中的反流通常更大。尽管这种差异的原因需要进一步研究，但那些对总PR有显著单侧贡献的患者可能适合采用局部技术来减少反流。
