[Prognostic implications of left ventricular hypertrophy in arterial hypertension]

Abstract

Left ventricular hypertrophy (LVH) has been studied as a condition predisposing to cardiovascular disease over a 34 year period in the Framingham study. Whether present on the electrocardiogramme, chest X-ray or echocardiography, LVH is a harbinger of cardiovascular disease. It increases the risks of coronary artery disease, cardiac failure, cerebral haemorrhage and peripheral arterial disease. Its contribution to global cardiovascular risk is three times greater than that of hypertension which is the principal cause of LVH. Age, blood pressure and obesity are the three essential factors predisposing to LVH. Each contributes independently to the development of electrocardiographic hypertrophy (ECG-LVH). Increased left ventricular mass detected by echocardiography is commoner with age but apparently as the consequence of an increased prevalence of hypertension, obesity, coronary artery and valvular heart disease with age. The increase of left ventricular mass with age seems largely to be due to fatty hypertrophy and to hypertension. The risk associated with ECG-LVH is particularly important when St-T wave changes are associated with increased voltage. The outcome and prognosis of ECG-LVH and of silent myocardial infarction are similar. When overt coronary artery disease is present, ECG-LVH further increases the risk of cardiovascular events. Electrocardiographic LVH carries a worse prognosis than radiographic LVH which corresponds to anatomic hypertrophy. As the two forms of LVH contribute independantly to the cardiovascular risk, it is probable that they result from different physiopathological mechanisms.