Complexities of Left Atrial Analysis

Abstract

L eft atrial (LA) size is an important marker for the chronicity of elevated left ventricular (LV) filling pressures and a powerful predictor of adverse cardiovascular outcomes, including stroke, development of atrial fibrillation, congestive heart failure, and death.1 Among the different parameters available for assessing LA size, including diameter, area, and volumes, the latter has been shown to be the most accurate and robust predictor of cardiovascular outcomes.2 Accordingly, a significant amount of interest has recently emerged toward establishing the most accurate echocardiographic method to measure LA volumes. In this regard, Badano et al 3 must be commended for completing the first study, published in this issue of Circulation: Cardiovascular Imaging, providing normal reference values for both 2-dimensional (2D) and 3-dimensional (3D) LA volumes together with phasic function indices in a relatively large group of normal subjects over a wide range of ages. As the authors accurately expressed in their article: "availability of reference values…is a prerequisite for routine clinical application." See Article by Badano et alHistorically, LA size was initially assessed using M-mode echocardiography acquired from the parasternal long-axis view. In this transducer position, the antero-posterior dimension of the LA was recorded. Because this measurement is highly reproducible, it was widely adopted by echocardiography laboratories worldwide. It soon became obvious, however, that the LA does not dilate symmetrically in all directions when it enlarges. In fact, there is data to suggest that left atrial enlargement in the antero-posterior direction is constricted by the presence of the spine and sternum, and accordingly, most of the LA enlargement tends to occur in the superior-inferior direction. 4 Because of this, the use of m-mode echocardiography was strongly discouraged in the American Society of Echocardiography 2005 chamber quantification guidelines, and measurements of LA volumes were recommended for clinical practice. Both the 2005 and the current 2015 chamber quantification guidelines recommend the use of the biplane method of discs or the area-length method for the measurement of LA volumes. 5,6 The area-length method has been shown to result in atrial volumes that are slightly larger than those obtained using the biplane method of discs.7 Importantly, there was a major increase in the published values for normal LA volumes between the 2005 and 2015 chamber quantification guidelines. The upper normal reference value increased from 28 mL/m 2 for both men and women in 2005 to 34 mL/m 2 in 2015. 5,6 The main reason for this change is that the 2015 document had access to normative LA volume data obtained from a large number of studies conducted after the 2005 guidelines had been published. Most of the normative LA volume data from these additional studies were derived from subjects who had LA volumes measured from LA-dedicated views and LA volumes measured using the area-length method. [8][9][10][11][12][1...

Left ventricular volumes and ejection fraction quantification using an automated three‐dimensional adaptive analytic echocardiographic algorithm in pediatric population

“…As this method does not implement a specific tool for LA volume analysis, the agreement between 3D and HM results was not assessed . Nevertheless, taking into account the good results obtained for LV end‐diastolic, LV end‐systolic, and LVEF, it is not difficult to assume that the accuracy for LA volume would be similar . Similar results were found by Luo et al in a study with 53 Chinese patients older (mean age 17 years) than the subjects enrolled in the present study but with similar body mass index (21 kg/m 2 ).…”

“…12 Nevertheless, taking into account the good results obtained for LV enddiastolic, LV end-systolic, and LVEF, it is not difficult to assume that the accuracy for LA volume would be similar. 13 Although time has been not analyzed in this study, previous experienced confirmed that HM saves time. 7,14…”

Átrio esquerdo: Novas Percepções e Direcionamentos Futuros

“…que o operador selecione manualmente planos ortogonais não encurtados e corrija pequenos erros no traçado das bordas endocárdicas do AE feito pelo software. 5,14 A acurácia da análise dos dados em 3D é altamente dependente da qualidade da imagem, mais do que o 2D. Consequentemente, durante a aquisição de dados, o operador deve reduzir a profundidade da imagem e o ângulo setorial de modo que o AE esteja em foco.…”

“…4 Devido a facilidade e alta reprodutibilidade, os laboratórios de ecocardiografia continuam a reportá-la, apesar de serem fortemente desencorajadas nas últimas diretrizes de quantificação das câmaras cardíacas. 4,5 O principal motivo dessa recomendação é que o AE é uma cavidade assimétrica que não se dilata proporcionalmente em todas as direções. Na verdade, o AE tende a se alargar mais na direção craniocaudal do que ântero-posterior devido à presença da coluna e do esterno.…”

Left atrial-left ventricular angle, a new measure of left atrial and left ventricular remodeling

“…A recent interest in the malalignment of the left atrial (LA) long axis relative to that of the left ventricle (LV) has surfaced, particularly in relation to its potential implications on LA volume (LAVol) determination by two dimensionaltransthoracic echocardiography (2D-TTE) [1][2][3] which has been used to obtain most normative and predictive LAVol data [1,4,5]. In the clinical practice, the 4-chamber and 2-chamber 2D-TTE views are routinely optimized along the LV long axis such that an unrecognized angulation during scanning may lead to LA foreshortening and underestimation of LAVol by 2D-TTE [1,3,5,6].…”