Assessment Of The Left Ventricular Function In Patients With Uremia Using Layer-specific Strain

Objective:To evaluate the circumferential systolic function of the left ventricle(LV)with different configurations from endocardium,midmyocardium and epicardium respectively in patients with uremia using layer-specific two-dimensional speckle tracking echocardiography(2D-STE).Methods:We enrolled 78 patients(44 men and 34 women;age range:18~75 years;mean age:46.8±10.3 years)who were diagnosed with uremia were recruited at the Second Affiliated Hospital of Dalian Medical University from May 2014 to June 2015.The eligibility criteria were as follows:Renal disease as the primary disease;Serum creatinine(SCr)level of>707μmol/L;Age of>18 years;Entire hemodialysis duration of at least 6 months,and hemodialysis schedule of thrice a week for 4h using low-flux dialysis filters;LV ejection fraction(LVEF)of>50%;No pericardial effusion.The exclusion criteria were as follows:Cardiovascular diseases:any history of congenital heart disease,ischemic heart disease,valvular heart disease,rhythm problems,pulmonary hypertension,primary hypertension,etc;Endocrine and metabolic diseases,such as diabetes mellitus,systemic lupus erythematosus,and hyperthyreosis;Any history of cardiovascular treatment,such as cardiopulmonary surgery or cardiovascular-related medications.According to the LV mass(LVM)index(LVMI),all patients were divided into two groups:LV normal(LVN)group:42 patients(men:24,LVMI of≤115 g/m~2;women:18,LVMI of≤95 g/m~2;age range:25~68 years,mean age:45.3±9.5 years);LV hypertrophy(LVH)group:36 patients(men:20,LVMI of>115g/m~2;women:16,LVMI of>95 g/m~2;age range:40~72 years,mean age:48.2±8.9years).38 age-and sex-matched healthy individuals(men:22,women:16;age range:23~72 years,mean age:44.8±9.1 years)were included in the control group.None of the selected individuals had any related diseases,and all clinical related examinations were normal.1.The demographic and clinical characteristics assessment:The age,sex,height and body mass of all subjects were recorded and the body mass index(BMI)was calculated,and each subject’s blood pressure,SCr level,blood urea nitrogen(BUN)level,immunoreactive parathyroid hormone(iPTH)level were measured and recorded;2.The parameters of conventional echocardiography assessment:including left atrial end-systolic diameter(LADs),LV end-diastolic dimension(LVDd),interventricular septum diastolic thickness diameter(IVSTd),and end-diastolic thickness of the LV posterior wall(LVPWTd),the early diastolic mitral inflow velocity(E)and late diastolic mitral inflow velocity(A),and the E/A ratio was also calculated,the LVEF was measured using biplane Simpson’s method.The LVMI was calculated using the following equation:LVMI=LV mass(LVM)/body surface area(BSA);LVM=0.8×{1.04[(LVDd+LVPWTD+IVSTd)~3–(LVDd)~3]}+0.6;BSA=0.0061×height(cm)+0.0128×weight(kg)–0.1529.3.The parameters of 2D-STE assessment:circumferential strain(CS)curves and data in endocardium,midmyocardium,and epicardium were measured from mitral annulus,papillary muscle and apical levels of the short-axis view via Echo PAC image analysis work station,respectively.Results:1.The results of demographic and clinical characteristics:There were no significant differences among the three groups with respect to age,sex,heart rate and BMI(P>0.05).The SCr level,blood urea nitrogen(BUN)level,immunoreactive parathyroid hormone(iPTH)level,the systolic and diastolic blood pressures of the LVN and LVH groups were significantly higher than those of the control group(P<0.05);2.The results of conventional echocardiographic parameters:The LADs,LVPWTd and IVSTd of the LVH group were significantly higher than those of the control and LVN groups,the E/A ratio of the LVH group was significantly lower than that of the control and LVN groups(P<0.05),there were no significant differences with respect to LVDd and LVEF(P>0.05).There were no significant differences in LVDd,IVSTd,LVPWTd,LADs,E/A ratio and LVEF between the control and LVN groups(P>0.05).3.The results of 2D-STE parameters:(1)The CS of the myocardial layers among three groups were kept the gradient features:endocardium>midmyocardium>epicardium;(2)There were no significant differences in the CS of the endocardium,midmyocardium and epicardium between the LVN and control groups(P>0.05).Compared to the LVN and control groups,there were no significant difference in the CS of the three myocardial layers in the apical level of the LVH group(P>0.05),there were no significant difference in the CS of the epicardium in mitral annulus and papillary muscles levels of the LVH group(P>0.05).The CS of the endocardium and midmyocardium in the mitral annulus and papillary muscles levels of the LVH group were significantly lower than those in same section of the LVN and control groups(P<0.05).Conclusions:1.In the development of uremic cardiomyopathy,degree of the circumferential systolic function impaired of the LV with different configurations is different,and degree of function impaired of three myocardial layers is different.2.2D-STE could quantitatively evaluate circumferential systolic function of the LV with different configurations in patients with uremia,it could provide valuable information for diagnose the degree of myocardial damage in patients with uremia.