Left Ventricular Diastolic Function in Hypertension: Correlation with Ambulatory Blood Pressure and Left Ventricular Mass

Abstract

Using digitized M-mode Doppler echocardiography and 24-hour noninvasive ambulatory blood pressure monitoring, we evaluated the relationship between average level of blood pressure, left ventricular (LV) mass and diastolic function in 26 untreated hypertensives with normal LV diastolic diameter and systolic function. LV mass was increased in 13 patients; peak lengthening rate of LV diameter (+dD/dt), index of LV relaxation, was reduced in 15 patients, 6 of whom with normal LV mass; Doppler E/A ratio was < 1 in 9 patients, 4 of whom with normal LV mass. From 24-hour blood pressure monitoring we evaluated: average 24-hour (24-h), daytime (d) and nighttime (n) systolic (SAP), diastolic (DAP) and mean arterial pressure (MAP). We found a significant inverse correlation between LV mass and peak lengthening rate of LV diameter (r = -0.58; p < 0.005). LV mass weakly correlated only with SAP 24-h, SAP d and DAP d; E/A ratio correlated with SAP 24-h, SAP d, SAP n, MAP 24-h and MAP n; +dD/dt correlated with all blood pressure parameters. The weak correlation between LV mass and blood pressure confirms that blood pressure is only one of the factors responsible for development of myocardial hypertrophy. Diastolic function is significantly load dependent, being influenced not only by LV mass, but also and to a greater extent by the average level of arterial pressure. Peak lengthening rate is more consistently abnormal and more closely related to average values of blood pressure than Doppler E/A ratio, thus indicating that the two parameters reflect different aspects of LV diastolic function.