Echocardiography for evaluating right ventricular systolic pressure of hypoxic pulmonary hypertension mouse models
Objective To monitor heart-related parameters of hypoxic pulmonary hypertension(PH)mouse models induced by hypoxia alone and hypoxia combined with vascular endothelial growth factor receptor inhibitor SU5416 using echocardiography,and to construct the prediction equation of right ventricular systolic pressure(RVSP).Twenty-four C57BL/6J male mice were randomly divided into simple hypoxia group(group A),hypoxia combined with SU5416 group(group B),control group(group C),each group 8 mice.Hypoxic PH models were constructed with hypoxia alone and hypoxia combined with SU5416 in group A and group B,respectively.Echocardiography was performed before and during modeling(2,3,4 weeks after interventions),and the relevant parameters were obtained.RVSP was measured using right heart catheterization after the last echocardiography.The changes of ultrasonic parameters were observed,the correlations of ultrasonic parameters 4 weeks after intervention with RVSP were observed,and linear equations for predicting RVSP were established.Results With time going,during modeling,pulmonary artery diameter(PAD),PAD/aorta diameter(AOD)and right ventricle anterior wall thickness(RVAWT)increased,while heart rate,pulmonary artery acceleration time(PAAT),PAAT/pulmonary artery ejection time(PAET)and tricuspid annular plane systolic excursion(TAPSE)decreased in group A and B(all P<0.05).Three and 4 weeks after interventions,PAET,PAAT/PAET and TAPSE in group B decreased compared with those in group A(all P<0.05).Four weeks after interventions,RVSP in group A and B were highly correlated with PAD/AOD,RVAWT,PAAT,PAAT/PAET and TAPSE(all P<0.05).The linear regression equations of PAAT/PAET and TAPSE for predicting RVSP in simple hypoxic PH mice models included RVSP=-161.7 ×(PAAT/PAET)+63.85,as well as RVSP=-36.53 ×TAPSE+71.55,while of predicting RVSP in hypoxia combined with VEGFR-2 inhibitor PH mouse models were as follows:RVSP=-266.4 ×(PAAT/PAET)+91.59,RVSP=-69.14 × TAPSE+116.5.Conclusion Four weeks after inerventions,the phenotypes of hypoxic PH mouse models induced by hypoxia alone and hypoxia combined with SU5416 became obvious.Prediction equations of RVSP established based on PAAT/PAET and TAPSE obtained with echocardiography could provide references for relevant research.