Perfusion of isoprenaline in the dog may induce left ventricular hypertrophy (LVH), and this effect is suppressed by propranolol. Cultured foetal cardiomyocytes exposed to catecholamines show an increase in protein synthesis and RNA turnover. In spontaneously hypertensive rats (SHR), and perhaps in man, sympatholytic agents appear to be more effective in preventing or reversing LVH than some other antihypertensive drugs. These data suggest that, if increased load remains the main trigger mechanism for cardiac remodelling in arterial hypertension, the sympathetic nerve activity may modulate the response of the cardiac cells.