Kulik Thomas J, Harris Julia E, McElhinney Doff B
The Pulmonary Hypertension Program Department of Cardiology, Division of Cardiac Critical Care, Department of Nursing/Patient Services, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA. ,
Congenit Heart Dis. 2011 Nov-Dec;6(6):603-7. doi: 10.1111/j.1747-0803.2011.00580.x. Epub 2011 Oct 20.
Pulmonary venous hypertension is a well-characterized cause of pulmonary hypertension in adults, but little is known regarding the relationship between left atrial pressure and pulmonary arteriolar resistance in the young. Also, in adults relief of pulmonary venous hypertension results in a marked fall in pulmonary arteriolar resistance, but this could be different in children because vascular changes are more severe in young patients than adults with mitral stenosis. We inspected records of children at Children's Hospital Boston having mitral balloon valvuloplasty, and patients ≤5 years old having mitral valve replacement, to determine (1) the relationship between left atrial pressure and pulmonary arterial pressure and resistance (n = 94 children, median age 17.8 months) and (2) how pulmonary arteriolar resistance changes after mitral valve replacement.
The average indexed pulmonary arteriolar resistance was 7.8 ± 5.9 units and was unrelated to age but was positively related to left atrial pressure. There was great variability in pulmonary arteriolar resistance for any given left atrial pressure. Pulmonary arterial pressure (n = 16) and pulmonary arterial resistance (n = 9) were measured before and after mitral valve replacement (median = 29.4 months old). Despite preoperative indexed pulmonary arterial resistance of ≥5 units in 11 of 15 patients, postoperative pulmonary arterial pressure was substantially lower in all save three, and two patients with high pulmonary arterial pressure still had high left atrial pressure postoperatively (25 mmHg).
We conclude that in young children, as in adults, pulmonary arterial resistance generally falls greatly with reduction in left atrial pressure.
肺静脉高压是成人肺动脉高压的一个特征明确的病因，但对于年轻人左心房压力与肺小动脉阻力之间的关系却知之甚少。此外，在成人中，肺静脉高压的缓解会导致肺小动脉阻力显著下降，但在儿童中情况可能不同，因为年轻患者的血管变化比二尖瓣狭窄的成人更为严重。我们查阅了波士顿儿童医院接受二尖瓣球囊瓣膜成形术的儿童以及接受二尖瓣置换术的5岁及以下患者的记录，以确定：（1）左心房压力与肺动脉压力及阻力之间的关系（94名儿童，中位年龄17.8个月）；（2）二尖瓣置换术后肺小动脉阻力如何变化。
平均肺小动脉阻力指数为7.8±5.9单位，与年龄无关，但与左心房压力呈正相关。对于任何给定的左心房压力，肺小动脉阻力存在很大差异。在二尖瓣置换术前和术后测量了肺动脉压力（n = 16）和肺动脉阻力（n = 9）（中位年龄 = 29.4个月）。尽管15例患者中有11例术前肺动脉阻力指数≥5单位，但除3例患者外，所有患者术后肺动脉压力均大幅降低，2例肺动脉压力高的患者术后左心房压力仍较高（25 mmHg）。
我们得出结论，在幼儿中，与成人一样，随着左心房压力的降低，肺动脉阻力通常会大幅下降。
