Autonomic cardiovascular control and diastolic dysfunction in hypertensive subjects.

Background: Early hypertension is associated with left ventricular diastolic dysfunction due to increased end-diastolic pressure. This increase, through the cardiopulmonary reflexes, can influence autonomic cardiovascular control.

Methods: We assessed autonomic nervous system modulation of cardiovascular signals by power spectral analysis of RR interval and systolic arterial pressure variabilities in subjects with recently diagnosed hypertension with or without diastolic dysfunction and in normotensive control subjects.

Enhanced platelet release of superoxide anion in systemic hypertension: role of AT1 receptors.

Background: Enhanced oxidative stress has been observed in hypertension, but the underlying mechanism has not been fully clarified.

Objective: To study the relationship between oxygen free radicals and hypertension, using platelets as a tool to measure the cellular production of superoxide anion (O2).

Design: Forty patients with hypertension were allocated randomly to groups to receive either irbesartan, an inhibitor of angiotensin II type 1 (AT1) receptors (n = 20), or a diuretic (hydrochlorothiazide) (n = 20).

QT-interval variability and autonomic control in hypertensive subjects with left ventricular hypertrophy.

Left ventricular hypertrophy is a risk factor for sudden death. Malignant ventricular arrhythmias originate from altered cardiac repolarization. Ample data have described spatial abnormalities in cardiac repolarization [QT interval (QT) dispersion] in subjects with hypertension; more data are needed on temporal changes.