DECREASED ADRENERGIC RESPONSE IN HYPERTENSIVE PATIENTS WITHOUT LEFT-VENTRICULAR HYPERTROPHY

To analyze the adrenergic responses and to compare diem between hypertensive patients with and without left ventricular hypertrophy (LVH), left ventricular (LV) fractional shortening (FS) and end-systolic wall stress (ESS) were measured by echocardiography and the inotropic response to the perfusion of isoproterenol (0.02 mug/kg/min for 5 min) was studied in 25 hypertensive patients without LVH [H(-)] and 30 hypertensive patients with LVH [H(+)]. LVH was determined by echocardiography. Age, gender, heart rate, systolic and diastolic blood pressures, LV end-systolic and end-diastolic diameters, and FS were matched between the groups. The tests were performed before introduction of antihypertensive treatment or 4 weeks after its discontinuation. ESS showed a significant inverse linear relation with FS in all die subjects before isoproterenol infusion. The inotropic response to isoproterenol was measured as die increase of FS corrected for the decrease of ESS (DELTAFS/-DELTAESS), that is, the slope of die change of the relation between FS and ESS. The change in DELTAFS/-DELTAESS was significantly smaller (0.49 +/- 0.15 cm2/g, mean +/- SD) in H(-) than in H(+) patients (1.01 +/- 0.57 cm2/g) (p < 0.001). It is concluded that, compared with the H(+) group, adrenergic response is depressed in H(-) patients. This depression might be etiologically related to the phenomenon that LVH did not develop in the H(-) group in spite of the same level of pressure load as in the H(+) group.