Clinical Study On The Ultrasonic Integrated Backscatter Variance Of Left Ventricular Myocar Dium And Its' Relationship To The Diastolic Function In Patients With Hypertension

Objective: To evaluate the clinical application of ultrasonic backscatter parameters in assessing the lesion of myocardium in patients with hypertension. To study the relationship between averaged cyclic variation in integrated backscatter(ACVIB) and the diastolic function of left ventricle in patients with hypertension.Methods: We studied 117 essential hypertension patients and 30 sex-, age-matched adults with normal blood pressure and normal finding at ECG and echocardiography as controls. Their diastolic function was examined by mitral-inflow Doppler, Doppler tissue imaging and color M-mode. We acquired ejection fraction(EF), peak transmitral flow velocity in early diastole(E), peak transmitral flow velocity in late diastole(A), E/A ratio, mitral deceleration time (from peak E wave to baseline, DT), and isovolumic relaxation time (IVRT), Ea (mitral annular early diastolic peak velocity), Aa (mitral annular late diastolic peak velocity) and Ea/Aa, flow propagation velocity(Vp). Myocardial integrated bascatter(IBS), normalized IBS(IBS%), cyclic variation of IBS(CVIB), averaged cyclic variation of integrated backscatter (ACVIB)and transmural gradient of IBS(TGIB) of interventricular septum and left ventricular posterior wall were measured and analyzed.Results: The hypertension patients were classified in 4 groups according to left ventricular diastolic function: 34 hypertensive with normal diastolic function (groupl); 28 hypertensive with a delayed relaxation pattern (group 2); 36 hypertensive with a pseudonormal filling pattern (group 3); 19 hypertensive with a restrictive filling pattern (group4). 1. There were significant differences in IBS%, CVIB, ACVIB and TGIB between patients with abnormal diastolic function and the controls. 2. As assessed by ejection fraction<50%, part of the subjects studied exhibited systolic dysfunction. MWFS was decreased in group 4 compared with control group. Differences were found in E/A, IVRT, DT among the different groups. The Ea, Ea/Aa, Vp were significantly diminished in the 3 groups of hypertension with abnormal diastolic function, compared with control group. 3. ACVIB of left ventricle was correlated with E/A, DT, IVRT and with Ea, Ea/Aa, Vp significantly.Conclusions: Ultrasonic backscatter parameters are useful in determination of the degree of myocardium lesion of hypertension patients. Ultrasonic integrated backscatter is valuable in assessing the diastolic function of left ventricle in patients with hypertension.