Relation of hemodynamic load to left ventricular hypertrophy and performance in essential hypertension

ABSTRACT

BACKGROUND: Left ventricular function and left ventricular hypertrophy often show weak correlation with the degree of blood pressure in hypertensive patients. So we assessed correlation of hemodynamic load to left ventricular hypertrophy and left ventricular performance, and whether left ventricular wall stress is the major factor on the regulation of left ventricular function. METHODS: Relationships between echocardiographic hemodynamic parameters and indices of left ventricular hypertrophy and left ventricular function were evaluated in 40 patients with essential hypertension who have not been previously treated. RESULTS: Left ventricular mass index correlated weakly with blood pressure, cardiac index, and stroke volume. End-diastolic left ventricular relative wall thickness, as an index that assess the severity of concentric hypertrophy showed significantly negative correlation with cardiac index (r=-0.49, p<0.001),stroke index(r=-0.46, p<0.001) and a positive correlation with total peripheral resistance (r=0.55, p<0.001). Furthermore, patient with cardiac indices tend to have higher end-diastolic wall thickness at any given level of blood pressure. Fractional shortening suggesting left ventricular systolic function was not related with blood pressure. stroke volume, cardiac index, left ventricular mass index, and peak systolic wall stress. In contrast there were significant negative correlations between fractional shortening with mean wall stress index (r=-0.42, p<0.005) and with end-systolic wall stress (r=-0.72, p<0.001). CONCLUSIONS: These results suggest that anatomic and hemodynamic changes may be pathophysiologically interdependent and left ventricular function was regulated by the level of left ventricular wall stresses reflecting afterload (blood pressure).