Left ventricular wall thickness and plasma catecholamines in borderline and stable essential hypertension

Abstract

It has been suggested that sympathetic overactivity has a pathogenetic relevance to left ventricular hypertrophic development, even apart from its effect on and in essential hypertension. To evaluate this possibility by echocardiographic and polygraphic methods, we studied left ventricular wall thickness and function and their possible relationship to plasma renin activity and plasma catecholamines in 11 normal subjects, 13 borderline hypertensives and 11 stable hypertensives without radiological or electrocardiographic signs of left ventricular hypertrophy. Compared with normal, borderline hypertensives showed an increase in interventricular septum (IVS) thickness ( P < 0.01) and IVS/posterior wall (PW) thickness ratio ( P < 0.01) together with an increased supine and upright plasma norepinephrine (NE; P < 0.01); there was also a decreased pre-ejection period (PEP; P < 0.01), PEP/left ventricular ejection time ratio ( P < 0.01) and total electromechanical systole ( P < 0.05). In stable hypertensives, PW thickness was greater than it was both in normals ( P < 0.01) and in borderline hypertensives ( P < 0.01) and IVS thickness was higher than in normals ( P < 0.05). Positive correlations between supine ( P < 0.001), upright ( P < 0.05) NE and both IVS thickness and IVS/PW thickness ratio were found in borderline but not in stable hypertensives. These results support the hypothesis recently put forward that IVS hypertrophy may represent an early stage of essential hypertension-induced LVH, which afterwards extends to the left PW; furthermore the results suggest that the sympathetic overactivity may play a role in the IVS hypertrophy development in borderline hypertensives.