Left ventricular hypertrophy is enlargement and thickening (hypertrophy) of the walls of your heart's main pumping chamber (left ventricle).Left ventricular hypertrophy is more common in people who have uncontrolled high blood pressure. But no matter what your blood pressure is, developing left ventricular hypertrophy puts you at higher risk of a heart attack and stroke.Treating high blood pressure can help ease your symptoms and may reverse left ventricular hypertrophy.