Adrenergic nervous system and left ventricular mass in primary hypertension

A link between the activity of the adrenergic nervous system and left ventricular hypertrophy has frequently been found in hypertensives. In 16 patients with untreated primary hypertension of mild to moderate degree, we have evaluated the possible correlations between echocardiographic left ventricular mass (LVMe) and sympathetic nervous system activity, using pressor response to exogenous noradrenaline infusion, measurement of 24-h catecholamine urinary excretion and pressure response to ergometric exercise. Pressor response to noradrenaline infusion was significantly related to echocardiographic measures of left ventricular hypertrophy (correlation coefficients were: -0.60 for LVMe; -0.51 for septal thickness (ST); -0.51 for posterior wall thickness). Left ventricular mass was also related to systolic blood pressure measured during ergometric exercise (correlation coefficients were: 0.52 with LVM index, 0.51 with LVMe and 0.61 with ST). Arterial wall hypertrophy has been identified as being responsible for the vascular hyperreactivity in hypertension. A likely explanation of our findings is that the degree of left ventricular hypertrophy is associated with the degree of structural alterations of the resistance vessels and that the vascular impairment is responsible for the increased pressure response to noradrenaline.