Determinants of Doppler indexes of left ventricular diastolic function in normal subjects (the Framingham Heart Study)

Abstract

Normative Doppler values and determinants of left ventricular (LV) diastolic function in healthy subjects have not been fully elucidated. Subjects from the Framingham Heart Study were examined to describe reference values and determinants of echocardiographic Doppler indexes of diastolic function. One hundred twenty-seven randomly selected, rigorously defined, normal subjects, approximately evenly distributed by sex and age from the third through the eighth decades were studied by Doppler echocardiography. Normative values for 7 frequently used Doppler indexes of LV diastolic function are presented. Doppler indexes of LV diastolic function change dramatically with age; the peak velocity of early filling divided by late filling (peak velocity E/A) ranges from a mean of 2.08 ± 0.55 for subjects in their third decade to 0.84 ± 0.29 for those in their eighth decade. A peak velocity E/A ratio <1 is abnormal in subjects aged <40 years, but occurs in most subjects aged ⪰70 years. The high correlations between age and Doppler indexes of LV diastolic function;are not greatly attenuated after adjustment for other clinical parameters associated with diastolic function; the multivariate partial correlation coefficient between age and peak velocity E/A is −0.80 (p <0.0001). Heart rate, PR interval, LV systolic function, sex and systolic blood pressure are minor determinants of Doppler indexes of diastolic function. Body mass index, left atrial diameter, and LV wall thickness, internal dimension and mass have little or no association with Doppler indexes in healthy subjects. Age is the predominant determinant of Doppler indexes of LV diastolic function in normal subjects, whereas heart rate, PR interval, sex, systolic blood pressure and LV systolic function have a lesser impact. The independence of the age-diastolic function relation from changes in physiology and LV geometry is consistent with an intrinsic reduction in LV distensibility with advancing age. These findings indicate that Doppler diastolic function should be assessed with reference to age-specific normative values.