Left ventricular hypertrophy, or LVH, refers to a heart's left pumping chamber that has thickened and may not be pumping efficiently. High blood pressure or aortic stenosis is a secondary cause the heart muscle to work too hard. In response to the pressure overload, the heart's inner walls may thicken. These thicker walls can cause the left ventricle to weaken, stiffen, and lose elasticity, thereby preventing proper blood flow. LVH is also a feature of hypertensive heart disease.