Metabolic syndrome and biventricular hypertrophy in essential hypertension

Abstract

Long-standing hypertension is associated with left ventricular hypertrophy (LVH) that may be either concentric or eccentric. It has been shown that hypertension is also associated with hypertrophy and fibrosis of the right ventricle. 1 The hypertrophy of the right ventricle is not because of pressure overload, and therefore non-haemodynamic factors, such as angiotensin II, aldosterone, insulin, the sympathetic nervous system and endothelin may be involved in this process.The contribution of non-haemodynamic factors to the development of cardiac hypertrophy may also explain why in several studies it has been shown that the increase in left ventricular mass preceded hypertension. For example, we followed 500 young healthy Israeli air force aviators, who underwent echocardiography at the start of their military service for an average period of 7.5 ± 3.0 years. 2 We showed that interventricular septal thickness predicted the development of systolic hypertension suggesting that interventricular septum thickening is not merely a result of long-term elevation of blood pressure. These results suggest that LVH is an early marker of hypertension and is caused by non-haemodynamic factors that are also responsible for hypertension, such as over activity of the sympathetic nervous system or the renin-angiotensin system. Heart muscle may be more sensitive than blood pressure to the activation of these systems, and heart muscle changes appear earlier than the elevation in blood pressure.Left ventricular hypertrophy is an independent risk factor for cardiovascular (CV) disease. 3 Hypertensive cardiomyopathy is associated with impaired cardiac diastolic and systolic functions. 4 In hypertensive patients, contractility deteriorates as left ventricular mass increases. 5 Diabetes mellitus accelerates the development of LVH in patients with essential hypertension independent of arterial pressure. 4 In this issue of the Journal of Human Hypertension, Cuspidi et al. 6 show that metabolic syndrome (MS) also accelerates the development of LVH, as hypertensive patients of both genders had more cardiac alterations when they have MS.Earlier studies have shown that hypertensive patients with MS are more susceptible to develop LVH than those without MS. 7-10 Mule et al. 9 showed in 475 non-diabetic subjects with mild-to-moderate essential hypertension, of whom 40% had MS, that left ventricular mass was significantly higher in those with MS than in those without it. The relationship between MS and left ventricular mass was not affected by gender. An additional study by Mule et al. 10 showed that MS may have a deleterious influence on left ventricular structure and function even in white coat hypertension.The deleterious effect of MS on the left ventricle is well established; however data regarding the effect of MS on the development of right ventricular hypertrophy are lacking. Indeed, the study by Cuspidi et al. 6 shows that MS accelerates, in hypertensive patients, the development of right ventricular hypertrophy and diastolic dysfunction ...