Left ventricular hypertrophy (LVH) is the thickening of the myocardium (muscle) of the left ventricle of the heart.

While ventricular hypertrophy occurs naturally as a reaction to aerobic exercise and strength training, it is most frequently referred to as a pathological reaction to cardiovascular disease, or high blood pressure.

While LVH itself is not a disease, it is usually a marker for disease involving the heart. Disease processes that can cause LVH include any disease that increases the afterload that the heart has to contract against, and some primary diseases of the muscle of the heart.

Causes of increased afterload that can cause LVH include aortic stenosis, aortic insufficiency and hypertension. Primary disease of the muscle of the heart that cause LVH are known as hypertrophic cardiomyopathies, which can lead into heart failure.

Long-standing mitral insufficiency also leads to LVH as a compensatory mechanism.

The principal method to diagnose LVH is echocardiography, by which the thickness of the muscle of the heart can be measured. The electrocardiogram (ECG) often shows signs of increased voltage from the heart in individuals with LVH, so this is often used as a screening test to determine who should undergo further testing.