Both coronary artery disease and aging produce a similar pattern of left ventricular diastolic dysfunction with increased left atrial (LA) activity. We studied the Doppler left ventricular filling pattern in 75 patients (age 40-91 years) with coronary artery disease. A linear correlation with age was found for isovolumic relaxation time, peak atrial flow velocity, and atrial filling fraction; an independent effect of age and LA size on these parameters could be demonstrated. As an overall correlation was found between LA diameter and atrial function indexes, we compared such parameters among four subgroups with increasing LA size; the LA function indexes were increased with minor degrees of LA dilation and decreased with further LA expansion. As LA dilation was found only in older patients, it can be supposed that the combined effects of aging and disease on LA wall stress accounted for LA dilation and dysfunction in these subjects.