Left atrial appendage flow velocities in subjects with normal left ventricular function

The objectives of this study were to establish reference values and define the determinants of left atrial appendage (LAA) flow velocities in the gene ral population. LAA flow velocities (contraction and filling velocities) we re assessed by transesophageal echocardiography in 310 subjects aged greate r than or equal to 45 years, sampled from the population-based Stroke Preve ntion: Assessment of Risk in a Community study. All subjects were in sinus rhythm, with preserved left ventricular systolic function (ejection fractio n greater than or equal to 50%), and without valvular disease. Values of LA A contraction and filling velocities were established for various age group s in the population. Age was negatively associated with LAA contraction and filling velocities, which decreased by 4.1 cm/s (p < 0.001) and 2.0 cm/s ( p < 0.01) for every 10 years of age, respectively. Contraction velocities w ere 5 cm/s higher in men than in women (p < 0.05). After adjusting for age and sex, heart rate was independently associated with LAA contraction veloc ities (p < 0.001; nonlinear association). Body surface area, left atrial si ze, left ventricular mass index, and a history of previous cardiac disease or hypertension showed no significant association with LAA flow velocities (p > 0.05). Furthermore, detailed analysis of 24-hour ambulatory blood pres sure data (available in 253 subjects) showed no association between various blood pressure parameters (systolic and diastolic blood pressure, out-of-b ed and in-bed measurements) and LAA flow velocities (all p > 0.05). In summ ary, the present study establishes the reference values for LAA flow veloci ties in a large sample of the general population. LAA flow velocities progr essively decline with age in subjects with preserved left ventricular systo lic function. (C) 2000 by Excerpta Medica, Inc.