Left Ventricular Performance in the Early Stages of Systemic Hypertension

To investigate whether and how frequently left ventricular (LV) systolic performance assessed with endocardial and midwall measurement is depressed in young subjects with mild systemic hypertension, we studied 722 borderline to mild hypertensive patients (mean age ± SEM 33 ± 0.3 years, mean office blood pressure (BP) 146 ± 0.4/94 ± 0.2 mm Hg) enrolled in the Hypertension and Ambulatory Recording Venetia Study and 50 normotensive controls with similar age and sex distribution. BP was measured with 24-hour ambulatory monitoring. LV dimensional and functional indexes were assessed by M-mode echocardiography and sympathetic activity from 24-hour urinary catecholamines. In 64 hypertensive subjects (8.9%) the LV midwall shortening-stress relation was <95% of the confidence interval in 50 normotensive controls. Subjects with depressed LV myocardial function had age, duration of hypertension, and LV mass similar to those of hypertensives with normal performance, and greater relative wall thickness (0.42 vs 0.37, p <0.001). Stroke volume and cardiac output were lower (p <0.001) in the former group. Among these 64 subjects, endocardial performance was depressed in 35 (group 1) and normal in 29 (group 2). Group 2 subjects had greater posterior wall (10.0 vs 9.5 mm, p = 0.03), ventricular septum (10.6 vs 10.1 mm, p = 0.05), and relative wall (0.44 vs 0.40, p <0.001) thicknesses than group 1 subjects. Urinary norepinephrine was 50% higher in group 2 subjects (106 vs 70 g/24 hours, p = 0.03). Stroke volume and cardiac output were similar in both groups. In conclusion, these results show that LV contractility may be depressed in young subjects with borderline to mild hypertension.