Hypertension, Left Ventricular Hypertrophy, and Heart Failure

Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular disease morbidity and mortality.[1] Both concentric and eccentric LVH independently increase risk of sudden cardiac death (SCD),[2] coronary artery disease (CAD), arrhythmias,[3] as well as heart failure.[4] Recent evidence shows up to 30% increased risk of cardiovascular events in patients with hypertensive target organ damage (TOD).[5] Hypertensioninduced TOD encompasses both microvascular injury, namely, nephropathy or retinopathy, and macrovascular injury, namely, coronary or peripheral artery disease causing myocardial infarction or stroke. LVH is another manifestation of TOD from uncontrolled blood pressure and will remain the focus of this article. Arterial hypertension leads to organ damage on much of the body, with LVH a well-known complication. In fact, LVH is the cardinal manifestation to increased hemodynamic afterload in hypertension.[6] Remodeling of the left ventricle (LV) occurs in response to chronic hemodynamic overload from hypertension. Recently, published data from over 6000 Framingham study patients showed that a one standard deviation increase in mean arterial pressure and central pulse pressure was associated with 37%–45% increased incidence of LVH.[5] Cuspidi et al. showed that up to 41% of hypertensive patients and 77% with hypertension and a prior history of diabetes mellitus or cardiovascular disease exhibit echocardiographic evidence of LVH.[7] Insulin resistance is in itself a mediator of LVH, with up to 70% of type two diabetics exhibiting increased LV mass.[8,9] Increased aortic pulsatile load ultimately leads to increased LV wall stress and LVH.[10] Indeed, the maladaptive mechanisms involved in the developed of LVH are the first step toward overt cardiovascular disease such as congestive heart failure (CHF), ischemic heart disease, arrhythmias, and stroke.[2,11] LVH increases myocardial oxygen consumption while reducing coronary blood flow – predisposing the patient to angina pectoris, myocardial infarction, and sudden cardiac death. Untreated hypertension along with LVH leads to impaired diastolic filling due to LV stiffness.[10] Hypertension precedes the diagnosis of heart failure in up to 91% of patients with newly diagnosed CHF and remains the most important cause of diastolic heart failure.[12,13] It has been shown that long-standing and untreated hypertension leads to heart failure. Pressure overload caused Abstract