[Evaluation of cardiac function at rest and under acute loading in patients with essential hypertension using pulsed...

We studied 45 untreated patients with mild to moderate essential hypertension (EH) and 27 normotensive controls to assess the relationship between pulsed Doppler echocardiographic parameters and cardiac function, and the effects of acute changes in preload or afterload on these parameters. The following pulsed Doppler parameters were measured: as left ventricular (LV) inflow parameters, rapid filling peak velocity (R), presystolic peak velocity (A), and A/R; as LV outflow parameters, preejection period (PEP), ejection period (ET), ET/PEP, and peak velocity (PV). These parameters were compared with those relating to cardiac function, such as age, interventricular septal thickness (IVST), LV mass index (LVMI), % fractional shortening (%FS), LV end-systolic wall stress (WS), blood pressure, and heart rate. The changes in preload and afterload were induced by sodium nitroprusside (SNP) or phenylephrine infusion, which caused decreases or increases in the mean blood pressure by approximately 15%. 1. LV inflow parameters: Compared to normals, A and the A/R were higher in the group EH (p less than 0.01). IVST in the group EH correlated with R and the A/R, but LVMI did not correlate with these parameters. In normals, A correlated with %FS and WS, but did not in the group EH. R and the A/R correlated with age in normals, but not in the group EH. 2. LV outflow parameters: There were no significant differences between the two groups. PV in the group EH correlated positively with %FS, and negatively with WS. The ET/PEP in normals correlated with %FS and WS, but not in the group EH. 3. Effects of SNP: Reduction in preload caused a decrease in R and an increase in the A/R in both the groups (p less than 0.01). At the same time, reduction in afterload induced increase in PV. 4. Effects of phenylephrine: An increase in afterload did not change A, R or the A/R, though PV decreased significantly in normals and tended to decrease in the group EH. In summary, though the significance of the pulsed Doppler parameters of the LV was not always the same between the two groups, these parameters may be used to evaluate cardiac function in EH, if we pay attention to the influence of preload and afterload.