The ratio of the transmitral early peak velocity (E) evaluated by conventional Doppler imaging over early diastolic mitral annulus velocity (E') evaluated by tissue Doppler imaging has been proposed as a noninvasive marker for left ventricular filling pressure. We evaluated 174 normal patients and 86 patients with hypertension and LV hypertrophy to assess the effects of age, gender, and left ventricular hypertrophy on E' and E/E'. Age appeared to be the strongest determinant of E' and E/E', suggesting that in normal patients and in those with left ventricular hypertrophy, age-dependent cut-off values should be considered.