Ventricular hypertrophy means a thickening of the ventricle walls. This can then be described as eccentric or concentric.
Eccentric hypertrophy is where the wall thickens but the ventricle itself dilates therefore the wall is thickened but the ventricular chamber remains the same size.
Concentric hypertrophy is where the wall thickens which then makes the internal ventricular chamber smaller.