Left Ventricular Structure and Function in Subjects with Prehypertension
|School||Central South University|
|Course||Department of Cardiology|
|Keywords||prehypertension left ventricular structure and function ultrasonic cardiogram|
Objective:To investigate the changes of the left ventricular structure and function in subjects with prehypertension (SBP120-139mmHg or DBP80-89mmHg) by echocardiography in comparison with the normal BP (SBP<120mmHg and DBP<80mmHg) subjects.Methods:According to JNC7 classification of BP,136 selected subjects (BP<140/90mmHg) were divided into prehypertension group (n=92) and normal BP group(n=44).Left ventricular structure and function were evaluated by echocardiography. All of them were detected by conventional echocardiography for the following parameters:left ventricular end-diastolic diameter(LVIDd), left ventricular end-systolic diameter(LVIDs),left atrial diameter(LAd), interventricular septal thickness(IVST),left ventricular posterior wall thickness(LVPWT), left ventricle ejection fraction(LVEF), the early diastolic peak velocity of mitral inflow (E), the late diastolic peak velocity of mitral inflow (A),the left atrial area in the apical four chamber view and two chamber view in left ventricular systolic period when left atrial volume was maximum (A1, A2), and the distance from the midpoint of mitral annulus to the top of left atrium (L1, L2) and so on. LAVI,LVMI and E/A were also calculated. Pulsed-Wave Tissue Doppler Imaging (PW-TDI) was used to test early diastolic mitral annular velocity(Em),late diastolic mitral annular velocity(Am) and systolic mitral annular velocity(Sm). Em/Am, E/Em were calculated then. The relationships between BP levels and echocardiographic parameters were analyzed.Results:1.Compared with the normal BP group, LAd, LAVI, LVMI, E/Em were higher and Em, Em/Am were lower in the prehypertension group(P<0.05), no significant difference in LVIDd, IVST, LVPWT, LVEF, E/A and Sm between the two groups (P>0.05). 2.Linear correlation analysis showed that:within the normal BP group and prehypertension group,LAd and LVMI were positively correlated with systolic blood pressure(SBP) and mean arterial pressure(MAP), LAVI were positively correlated with SBP,diastolic blood pressure(DBP) and MAP,Em and E/Em were negatively correlated with SBP, DBP,MAP and pulse pressure(PP), Em/Am were positively correlated with SBP,MAP and PP,(P<0.05).There were no significant relationships between BP and LVIDd, IVST, LVPWT, LVEF, E/A, Sm (P>0.05).3.By multiple stepwise linear regression analysis where echocardiographic parameters were regarded as the dependent variable we found the multiple linear regression equations as follows: LAVI=0.539MAP+0.121E/Em+4.602, r2=0.241; LVMI=0.302SBP +29.416, r2=0.137; E/Em=0.082SBP+0.005PP+1.846, r2=0.203。Conclusion:1.LAd and LVMI in subjects with prehypertension were higher than that in subjects with normal BP.2. LAVI,E/Em in subjects with prehypertension were higher and Em,Em/Am were lower than that in subjects with normal BP.3.In normal BP group and prehypertension group, echocardiographic parameters such as LAVI,LVMI and E/Em were independently correlated with blood pressure.