Relationships between ambulatory arterial pressure and arterial distensibility as assessed by ambulatory measure of the QKD interval and echocardiographic measurement of left ventricular mass and relative wall thickness were evaluated in a population of 163 untreated hypertensive patients. The height-corrected QKD100-60 interval was significantly correlated with left ventricular mass (LVM; r = -0.29, P<.001) and with relative wall thickness (r = -0.31, P<0.001). In a multivariate analysis, LVM was significantly correlated with mean arterial pressure, pulse pressure, and age, whereas the relative wall thickness was correlated with the QKD interval and the mean arterial pressure. The concentric character of the LVH of the hypertensive patient was thus linked to the reduction in arterial distensibility.