Abstract:Objective: To explore the correlation between the inferior vena cava collapse index and the long axis strain of the right ventricle and pulmonary hypertension.Methods: The clinical data of 94 patients with pulmonary hypertension (observation group) and 35 healthy subjects (control group) were selected for retrospective analysis. The selection time was from February 2018 to May 2020. The observation group was based on pulmonary artery systolic pressure. Divided into mild group (30-49mmHg, n=32), moderate group (50-69mmHg, n=32), severe group (≥70mmHg, n=30), and compare the vena cava collapse index and right ventricular long axis strain , Pulmonary artery mean pressure (mPAP), pulmonary capillary resistance (PVR), pulmonary capillary wedge pressure (PCWP), analyze the vena cava collapse index, the correlation between the long axis strain of the right ventricle and mPAP, PVR, PCWP, and evaluate the vena cava Collapse index, AUC value, sensitivity, specificity, and Youden index for the diagnosis of pulmonary hypertension by the long-axis strain of the right ventricle. Results: The vena cava collapse index, right ventricular long axis strain, and PCWP of the observation group were lower than those of the control group, while mPAP and PVR were higher than those of the control group (P<0.05). The vena cava collapse index, right ventricular long-axis strain, and PCWP of the severe group were lower than those of the mild and moderate groups, while mPAP and PVR were higher than those of the mild and moderate groups (P<0.05). Spearman correlation showed that the vena cava collapse index and the long axis strain of the right ventricle were negatively correlated with severity (r=-796/-895, P<0.05). Pearson correlation showed that the vena cava collapse index was negatively correlated with PVR (r=-0.410, P<0.05), and positively correlated with PCWP (r=0.262, P<0.05); the long axis strain of the right ventricle was negatively correlated with PVR ( r=-0.454, P<0.05), which was positively correlated with PCWP (r=0.288, P<0.05). ROC curve analysis showed that the AUC values of the vena cava collapse index and the long axis strain of the right ventricle to diagnose pulmonary hypertension were (0.911, 0.938, P<0.05). Conclusion: Inferior vena cava collapse index and right ventricular long axis strain are negatively correlated with pulmonary artery pressure, which have important predictive value for PAH.