Correlation Study Between Ascending Aortic Elasticity And Left Ventricular Systolic Function In Patients With Bicuspid Aortic Valve

Objective: This study measured the elasticity of ascending aorta and the global myocardial peak strain of left ventricle in patients with bicuspid aortic valve by velocity vector imaging,aimed to explore the correlation between the elasticity of ascending aorta and the systolic function of left ventricle.Methods:In strict accordance with the inclusion and exclusion criteria,40 patients with bicuspid aortic valve were selected as the case group.According to proximal ascending aortic diameter,the case group was divided into case 1 group(≤35mm)and case 2 group(>35mm).20 healthy subjects who matched the age and sex of the case group were included in the control group.1.First,the diameter of proximal ascending aorta at the end of diastolic and systolic phases were measured by M-mode ultrasound,and the blood pressure was measured and recorded at the same time.Then through the formula we calculated the ascending aortic elasticity parameters:aortic strain,aortic stiffness index and aortic distensibility.Then using velocity vector imaging we measured that anterior wall and posterior wall of the aortic long axis systolic and diastolic velocity,displacement,strain and strain rate.Velocity vector imaging was used to measure the ascending aortic global radial strain and global circumferential strain and the left ventricular global longitudinal peak strain and the left ventricular global radial peak strain and the left ventricular global circumferential peak strain and other parameters.3.All parameters were compared among the three groups.Results 1、Ascending aortic elasticity parameters by M-mode ultrasound:compared with the control group,aortic systolic dimension,aortic diastolic dimension,aortic stiffness index in case 2 group and aortic diastolic diameter in case 1 group were increased significantly(P<0.05).Aortic strain,aortic distensibility in case 2 group and aortic strain in case 1 group were decreased significantly(P<0.05).2、Strain parameters of the aortic long axis:compared with the control group,the global longitudinal peak strain and the global longitudinal peak strain rate of the anterior wall,the global longitudinal peak strain rate of the posterior wall in case 1 group were significantly reduced(P < 0.05).The global longitudinal peak strain,the global longitudinal peak strain rate of the anterior wall and the global longitudinal peak velocity,the global longitudinal peak strain,the global longitudinal peak strain rate of the posterior wall in case 2 group were significantly reduced(P < 0.05).3、Strain parameters of the aortic short axis:compared with the control group,the ascending aortic global radial strain rate and the ascending aortic global circumferential strain rate in the case 1 group were significantly reduced(P < 0.05).The fraction area change of the aortic short axis,the ascending aortic global radial strain,the ascending aortic global radial strain rate,the ascending aortic global circumferential strain,the ascending aortic global circumferential strain rate in the case 2 group were significantly reduced(P < 0.05).4、Global peak strain parameters of left ventricular:compared with the control group,left ventricular global longitudinal peak strain in case 1 group and left ventricular global longitudinal peak strain,left ventricular global radial peak strain,left ventricular global circumferential peak strain in case 2 group were reduced(P <0.05).5、Correlation analysis of ascending aortic elasticity parameters and the left ventricular global peak strain parameters:left ventricular global longitudinal peak strain in the case group showed significant positive correlation to ascending aortic elasticity parameters represented by aortic strain,aortic distensibility,the global longitudinal peak strain of the anterior wall and the global longitudinal peak strain of the posterior wall,the ascending aortic global radial strain and the ascending aortic global circumferential strain (r=0.528,p=0.000;r=0.513,p=0.001;r=0.287,p=0.026;r=0.302,p=0.019;r=0.324,p=0.011;r=0.343,p=0.007),negative correlation to aortic stiffness index(r=-0.388,p=0.002).Conclusion:1、In the early stage of patients with bicuspid aortic valve,the ascending aorta elasticity is reduced and the left ventricular global longitudinal peak strain is decreased regardless of the proximal ascending aortic diameter.2、There is a correlation between ascending aorta elasticity and the left ventricular global longitudinal peak strain in patients with bicuspid aortic valve.