Left Ventricular Hypertrophy on ECG
Left ventricular hypertrophy (LVH) means that the muscle of the left pumping chamber of the heart (left ventricle) is thickened. The left ventricle's job is to pump blood to the body, and conditions that increase the work the left ventricle has to do can lead to thickening of the muscle. High blood pressure, tight valves, certain malformations of the heart (hypertrophic cardiomyopathy) and some medications (such as certain steroids) can lead to LVH, but in many cases the cause is not known. LVH can also be normal in people who are very athletically conditioned.
In addition, very often the EKG suggests LVH when in fact the heart muscle is normal - this is a weakness of EKGs as a test.
If there is any concern about whether a child with LVH on ECG actually has a heart problem, the usual next step would be to consider a consultation with a pediatric cardiac specialist and usually an ultrasound of the heart (echocardiogram).