Hypertrophy technically refers to each of the heart cells growing larger in size, but generally the term is used referring to left ventricular hypertrophy (LVH) means that the heart muscle has become thicker.
The two bottom chambers of the heart act as pumping chambers; the left ventricle pumps to the body, and the right ventricle pumps to the lungs.
As the left ventricle has to pump for the whole body, it has a thicker muscle. If the ventricle is put under increased stress however, by having to work harder, then the muscle hypertrophies, or becomes thicker.
Situations that put the ventricle under more stress:
- high blood pressure (hypertension)
- the ventricle has to work harder to pump against the high pressure
- narrowed aortic valve (aortic stenosis)
- the ventricle has to work harder to pump against the obstruction created by the narrow valve
- athletic training (athlete’s heart)
- specific types of exercise can provoke thickening of the heart muscle, however this is often not dangerous and can be reversed
Rarely, left ventricular hypertrophy can be genetic, as seen in hypertrophic cardiomyopathy (HCM).
Left ventricular hypertrophy can be suggested on a chest X-ray by cardiomegaly, however is best measured on echocardiography or cardiac MRI.
Treatment is focused on the underlying cause – most commonly by reducing blood pressure or treating the narrowed valve.