Does (mild) blood pressure causes more frequently dilation of heart than hypertrophy or other way around. which comes first dilation or hypertophy with mild bp?

Hypertrophy comes first. Dilatation comes later often with onset of heart failure. It is important to control even mild hypertension to avoid problems down the line. Wish you good health!

Depending on what you mean by "Mild hypertension" hypertrophy is more likely than dilatation. Hypertrophy is a response to the pressure overload of the ventricle and is likely to be less severe with mild hypertension. Remember however that blood pressure elevation can be variable and hypertrophy may appear to be disproportionate to the degree of BP elevation at the time of examination.