Left ventricular mass reduction during salt depletion in arterial hypertension.
Long-term therapy with antihypertensive agents that reduce sympathetic nervous system activity has been demonstrated by echocardiographic measurements to reverse left ventricular hypertrophy. This investigation evaluated the effects of salt depletion obtained by both chlorthalidone (25 mg/day) and severe restriction of salt intake (about 1016 mg Na+/day) on left ventricular mass (LVM) in as short a time as 12 weeks. Before the study, the patients had been off medication and on a balanced diet without salt restriction for at least 2 weeks; they were then randomly allocated to either the diuretic or low-salt regimen for 6 weeks and finally to alternative treatment according to a crossover model. Blood pressure, body weight, myocardial mass, and noninvasive measurements of left ventricular function (LVF) were determined at baseline and at the end of both periods of treatment. Results were evaluated by two-way analysis of variance in randomized blocks. Systolic and diastolic blood pressure and LVM were significantly and similarly reduced by diuretic therapy or salt restriction. A significant correlation was demonstrated between noninvasive measurements of LVM, expressed as cross-sectional area, and systolic blood pressure. No impairment of LVF could be detected over the treatment period.