Abstract: Objective　 We investigated the safety and efficacy of acute vasodilator testing using inhaled iloprost in PAH associated with CHD in children， in comparison with the traditional vasodilator phentolamine. Methods Fifty patients with PAH associated with CHD were collected from the Department of Pediatric Cardiology in Guangdong Cardiovascular Institute. Each patient received left and right heart catheterization followed by acute vasodilator testing using either direct injection of phentolamine into pulmonary artery or inhaled iloprost. After testing ， right heart catheterization was repeated. Hemodynamic parameters were calculated according to Fick’s principle. After evaluating the nature of PAH， patients were divided into two groups， the ‘functional’ PAH group and the ‘occlusive’ PAH group. The functional group received surgery. Diagnosis was corrected if we found the original ‘functional’ patient is actually ‘occlusive’ during follow-up. Results Phentolamine significantly increased the heart rate while inhaled iloprost only had slight effect. Both vasodilators lowered the mean pulmonary arterial pressure（mPAP） and pulmonary vascular resistance（PVR） and increased pulmonary blood flow（Qp）. Phentolamine decreased the mean systemic arterial pressure（mSAP） and systemic vascular resistance（SVR） and increased systemic blood flow（Qs） as well， while inhaling iloprost had no obvious effect on the systemic circulation. After inhaled iloprost， the decrease of mPAP and the ratio of pulmonary to systemic vascular resistances（Rp/Rs）， as well as the increase of the ratio of pulmonary to systemic blood flow（Qp/Qs）， were more significant in the ‘functional’ group than in the ‘occlusive’ group（P value 0.016， 0.024 and 0.030 respectively）. As for phentolamine injection， the decrease of mPAP and PVR were more significant in the ‘functional’ group than in the ‘occlusive’ group（P value 0.017 and 0.004 respectively）. Conclusion　Inhaling iloprost and pulmonary injection of phentolamine can both effectively differentiate the functional and occlusive PAH in CHD. Phentolamine influenced both pulmonary and systemic pressure， resistance， and blood flow， while inhaling iloprost mainly has effect on the pulmonary circulation. Inhaling iloprost can help to maintain hemodynamic stability and precedes phentolamine.

Key words: acute vasodilator testing, iloprost , pulmonary arterial hypertension, heart catheterization

摘要： 目的　探讨雾化吸入伊洛前列素进行急性血管扩张试验的价值。方法　研究对象为2007年2月至2008年5月在广东省心血管病研究所住院的50例先天性心脏 病合并肺动脉高压患儿，对所有患儿进行左右心导管检查，之后肺动脉内注射酚妥拉明或雾化吸入伊洛前列素进行急性血管扩张试验，试验后重复左右心导管检 查。根据Fick公式计算血流动力学参数。综合判断肺动脉高压性质，将患儿分成两组：动力组和梗阻组。动力组患儿进行手术治疗，术后定期随访并修正术前诊 断。结果　酚妥拉明会显著增高受试者的心率，而伊洛前列素对心率的影响较轻微；酚妥拉明和伊洛前列素都能够降低平均肺动脉压力和肺血管阻力，升高肺循 环血流量；酚妥拉明同时会降低平均主动脉压力和体循环阻力，升高体循环血流量，而伊洛前列素对体循环没有明显的影响。在使用伊洛前列素的急性血管扩张 试验中，平均肺动脉压力、肺血管阻力/体循环阻力和肺循环血流量/体循环血流量等参数的变化在动力组和梗阻组中差异无统计学意义（P 值分别为0.016、 0.024和0.030）。而使用酚妥拉明的急性血管扩张试验中，平均肺动脉压力和肺血管阻力两项参数的变化在动力组和梗阻组中差异有统计学意义（P 值分别为 0.017和0.004）。结论　在先天性心脏病合并肺动脉高压的患儿中，使用酚妥拉明或伊洛前列素进行急性血管扩张试验都能够有效区分动力性与梗阻性肺动脉高 压。酚妥拉明用药前后，肺循环和体循环的压力、阻力和血流量都有明显变化。而伊洛前列素雾化吸入以影响肺循环为主，可以保持相对平稳的血流动力学，在 安全性上优于酚妥拉明。

关键词: 先天性心脏病, 肺动脉高压, 心导管, 急性血管扩张试验, 伊洛前列素