中文题目:右下肺动脉直径与心脏超音波估计之肺动脉收缩...
中文題目,右下肺動脈直徑與心臟超音波估計之肺動脈收縮壓之關聯
英文題目,Correlation of right descending pulmonary artery diameter with
echocardiography-estimated systolic pulmonary artery pressure
1作 者,林斯晨, 蔡金築, 陳勁辰, 李瑞恆
1 服務單位,台北市立聯合醫院仁愛院區內科, 石牌振興醫院外科
Background: Enlargement of hilar branches of pulmonary artery, in particular of right descending pulmonary artery (RDPA), had been reported as a sign of elevated pulmonary artery pressure. In order to clarify the diagnostic value, we investigated the relation between RDPA diameter and systolic pulmonary pressure.
Methods: A total of 229 subjects without atrial fibrillation or congenital heart diseases were enrolled. Systolic pulmonary artery pressures were estimated by transthoracic Doppler echocardiography (Agilent SONOS5500). Briefly, while continuous wave detected tricuspid regurgitation flow, pressure gradient was calculated with Bernoulli equation, and then it plus right atrial pressure which was estimated by inferior vena cava width. Pulmonary hypertension was defined as systolic pressure greater than 30mmHg. Chest X-ray (PA view) was evaluated, mostly within 1 month of the echo exam. Width of RDPA was measured at the level of first bifurcation of the right pulmonary trunk on PACS system. We applied Student’s t-test to test difference of RDPA
diameter between groups with and without pulmonary hypertension. Linear regression model was used to assess the relation between RDPA diameter and systolic pulmonary pressure. Receiver operating characteristic (ROC) curve was done to find the best cut-off point for detecting pulmonary hypertension. P value under 0.05 was considered as statistically significant. Results: Student’s t-test revealed RDPA diameters were significantly higher in pulmonary hypertension group compared with normotensive group (p=0.02). Linear regression analysis
showed significant positive correlation between RDPA diameter and systolic pulmonary artery pressure (r=0.53, p=0.047). ROC analysis disclosed no optimal cut-off point of RDPA diameter to predict pulmonary hypertension. Since the upper limit of diameter of normotensive group was 21mm (mean+2SD), we tested how well that value in diagnosis of pulmonary hypertension. Its sensitivity, specificity, positive predictive value, negative predictive value, overall accuracy, positive likelihood ratio and negative likelihood value were 6.7%, 97.9%, 66.8%, 62.3%, 62.5%, 3.1 and 0.95, respectively.
Conclusions: Our study demonstrated RDPA diameter on chest radiographic film significantly correlated with echo-estimated systolic pulmonary pressure. But regarding as a diagnostic tool, RDPA diameter provided poor power in predicting pulmonary hypertension.