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

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