Echocardiography represents an innovative diagnostic method in patients with mild hypertension because it allows evaluation of target organ involvement and, thus, potentially may be of value in determining which patients might most benefit from treatment. In large-scale observations of mild to moderate hypertension, the electro-cardiogram and the chest x-ray film each identified approximately 5% of patients as having left ventricular hypertrophy (LVH), whereas echocardiography demonstrated this finding in almost 50%. This high sensitivity also was found in a study of young hypertensive patients (average age 28 years) among whom over 30% had left ventricular muscle wall thicknesses greater than the highest value found in age-matched normotensive controls; additionally, evidence for LVH was documented in a subgroup of young patients with labile hypertension whose blood pressures actually were normal at the time of the echocardiographic procedure.
Blood pressure is not the only cause of LVH. Other factors, including heightened activity of the sympathetic nervous system and the renin axis, may be important. Thus, treatment of hypertension with agents such as diuretics or vasodilators that fail to decrease sympathetic activity, or which might even increase it, often fails to produce regression of LVH. In contrast, agents with sympatholytic properties may exhibit beneficial effects on left ventricular muscle mass that are independent of their actions on blood pressure.
Address correspondence and reprint requests to Dr. Michael A. Weber at VA Medical Center (W130), 5901 East Seventh Street, Long Beach, CA 90822, U.S.A.
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