This study was aimed at improving the performance of standard electrocardiographic criteria of left ventricular hypertrophy (LVH) in essential hypertension using echocardiographic left ventricular mass as reference. In 923 white, untreated hypertensive subjects (mean age 51, prevalence of echocardiographic LVH 34%), sensitivity of electrocardiographic criteria of LVH varied between 9% and 33% and specificity was generally > or = 90%. The sum of Sv3 + RaVL (Cornell voltage) showed the closest association with echocardiographic left ventricular mass (r = 0.48, p < 0.001), and its performance was superior to that of Sokolow-Lyon voltage in a receiver-operating characteristic curve analysis. A modified partition value of the Cornell voltage was tested (> 2.4 mV in men and > 2.0 mV in women), that yielded a good combination between sensitivity (26% in men and 19% in women, overall 22%) and specificity (96% in men and 95% in women, overall 95%). When LVH at electrocardiography was defined as the positivity of at least 1 of the following 3 criteria--Sv3 + RaVL > 2.4 mV in men or > 2.0 mV in women, a typical strain pattern, or a Romhilt-Estes point score > or = 5--sensitivity increased to 39% in men and 29% in women (overall 34%) and specificity decreased to 94% in men and 93% in women (overall 93%). Sensitivity of electrocardiography progressively increased from the first to the fourth quartile of left ventricular mass in subjects with echocardiographic LVH.