Left Atrial Volumes and Function in Normal Subjects

Abstract

Left atrial (LA) emptying is biphasic; however, little information exists about the distribution of active and passive LA emptying. LA volumes and function were studied in 11 normal subjects with echocardiography using the biplane area length method. The LA volumes - maximal, at mitral valve opening; minimal, at mitral valve closure, and at onset of atrial systole (P wave on electrocardiogram) - were 46 ± 12, 29 ± 12, and 18 ± 7 cm^3, respectively. The LA passive emptying volume (maximal minus at P wave) was 17 ± 4 cm3, and the passive emptying fraction (passive emptying volume/maximal volume) was 0.39 ± 0.10. The LA active emptying volume (volume at P wave minus minimal) was 11 ± 5 cm^3, and the active emptying fraction (active emptying volume/volume at P wave) was 0.38 ± 0.07. The LA total emptying volume (maximal minus minimal) was 28 ± 5 cm^3, and the total emptying fraction (total emptying volume/maximal volume) was 0.62 ± 0.07. LA total emptying and active emptying volumes were directly related to LA maximal volume (r = 0.95) and volume at onset of atrial systole (r = 0.92), while LA passive emptying volume was not related to LA maximal volume. The study provides a framework for the evaluation of LA function and will help in understanding not only LA function, but also diastolic left ventricular function in health and disease states.

Left atrial volume assessed by transthoracic three dimensional echocardiography and magnetic resonance imaging: dynamic changes during the heart cycle in children

“…Studies based on cross sectional echocardiography do not discuss the role of the atrial appendage 23 9 10 19 In an MRI study in adults the appendage was included in the left atrial volume 4. As a reliable assessment of the left atrial appendage was not always possible in the present study, its volume was excluded from the reported left atrial volumes.…”

Cardiac adaptation to intensive training in prepubertal swimmers

“…Left atrial volumes were determined at mitral valve opening (maximal volume), at onset of atrial systole (P wave of the electrocardiogram), and at mitral valve closure (minimal) from the apical two‐ and four‐chamber views using the biplane area‐length method [13–15]. Left atrial systolic function was assessed with the left atrial active emptying volume = volume at onset of atrial systole – minimal and the left atrial active emptying fraction = left atrial active emptying volume/volume at onset of atrial systole.…”

Left atrial remodelling contributes to the progression of asymptomatic left ventricular systolic dysfunction to chronic symptomatic heart failure

“…Echocardiographic determination of LA volume can be accomplished using either the method of discs (Simpson's rule) or the arealength method and compares favourably with reference standards, such as magnetic resonance imaging and cine computerized tomography [32]. Moreover, by measuring the LA volume at onset of atrial systole (V p ) and the LA minimal volume (V min ), which correspond to the onset of P-wave of the electrocardiogram and mitral valve closure respectively, the LA active emptying (systolic) function can be assessed with the LA active emptying volume (V p -V min ) and fraction ([V p -V min ]/V p ) [33]. Finally, by combining volume indices of LA function and parameters of transmitral flow, the LA ejection force [34,35] and LA kinetic energy can de determined [36].…”