Grotenhuis H B, Kroft L J M, van Elderen S G C, Westenberg J J M, Doornbos J, Hazekamp M G, Vliegen H W, Ottenkamp J, de Roos A
Leiden University Medical Centre, Department of Radiology, 2300 RC Leiden, The Netherlands.
Heart. 2007 Dec;93(12):1604-8. doi: 10.1136/hrt.2006.109199. Epub 2007 Feb 3.
To assess pulmonary flow dynamics and right ventricular (RV) function in patients without significant anatomical narrowing of the pulmonary arteries late after the arterial switch operation (ASO) by using magnetic resonance imaging (MRI).
17 patients (mean (SD), 16.5 (3.6) years after ASO) and 17 matched healthy subjects were included. MRI was used to assess flow across the pulmonary trunk, RV systolic and diastolic function, and RV mass.
Increased peak flow velocity (>1.5 m/s) was found across the pulmonary trunk in 14 of 17 patients. Increased RV mass was found in ASO patients: 14.9 (3.4) vs 10.0 (2.6) g/m2 in normal subjects (p<0.01). Delayed RV relaxation was found after ASO: mean tricuspid valve E/A peak flow velocity ratio = 1.60 (0.96) vs 1.92 (0.61) in normal subjects (p = 0.03), and E-deceleration gradients = -1.69 (0.73) vs -2.66 (0.96) (p<0.01). After ASO, RV mass correlated with pulmonary trunk peak flow velocity (r = 0.49, p<0.01) and tricuspid valve E-deceleration gradients (r = 0.35, p = 0.04). RV systolic function was well preserved in patients (ejection fraction = 53 (7)% vs 52 (8)% in normal subjects, p = 0.72).
Increased peak flow velocity in the pulmonary trunk was often observed late after ASO, even in the absence of significant pulmonary artery stenosis. Haemodynamic consequences were RV hypertrophy and RV relaxation abnormalities as early markers of disease, while systolic RV function was well preserved.
通过磁共振成像（MRI）评估动脉调转术（ASO）后晚期肺动脉无明显解剖狭窄患者的肺血流动力学和右心室（RV）功能。
纳入17例患者（ASO术后平均（标准差）16.5（3.6）年）和17例匹配的健康受试者。采用MRI评估肺动脉干血流、RV收缩和舒张功能以及RV质量。
17例患者中有14例肺动脉干峰值流速增加（>1.5 m/s）。ASO患者RV质量增加：正常受试者为10.0（2.6）g/m²，ASO患者为14.9（3.4）g/m²（p<0.01）。ASO后发现RV舒张延迟：平均三尖瓣E/A峰值流速比值为1.60（0.96），正常受试者为1.92（0.61）（p = 0.03），E减速梯度为-1.69（0.73），正常受试者为-2.66（0.96）（p<0.01）。ASO后，RV质量与肺动脉干峰值流速（r = 0.49，p<0.01）和三尖瓣E减速梯度（r = 0.35，p = 0.04）相关。患者RV收缩功能保存良好（射血分数=53（7）%，正常受试者为52（8）%，p = 0.72）。
即使在无明显肺动脉狭窄的情况下，ASO后晚期也常观察到肺动脉干峰值流速增加。血流动力学后果是RV肥厚和RV舒张异常，作为疾病的早期标志物，而RV收缩功能保存良好。
