The left atrium in cardiac amyloidosis: a valuable but still underused observation window on the overall disease process

Abstract

Strain and strain rate imaging have now gained an established role in characterizing the different components of atrial function, e.g. the ability to expand during ventricular systole (reservoir function), early diastolic emptying (conduit function), atrial shortening (contraction), and, when associated with the estimation of left ventricular (LV) pressures, the resistance to deformation of the left atrium [left atrial (LA) stiffness]1 (Figure 1). In this issue of the Journal, Minamisawa et al.,2 from the Brigham and Women’s Hospital, Boston, USA, report the results of a detailed echocardiographic exploration of the left atrium in African-American carriers of the transthyretin (TTR) valine-to-isoleucine substitution (V122I) participating in the Atherosclerosis Risk in Communities study.3 This is the most frequent amyloidogenic TTR mutation, present in 3–4% of Black Americans and generally associated with a cardiac phenotype.4 The main finding of this analysis was that the LA minimum volume index was significantly greater, LA longitudinal strain was worse and multiple atrial abnormalities were more frequent in carriers compared to non-carriers, suggesting that LA dysfunction may be a useful echocardiographic marker of subclinical disease in V122I carriers, before overt late-onset amyloid cardiomyopathy develops. Despite many methodological limitations also admitted by the authors, the study is undoubtedly stimulating and raises, directly or indirectly, some relevant questions.