The Prognostic and Diagnostic Role of Atrial Strain in Cardiomyopathies: A Literature Review.

Atrial strain assessment, both by speckle-tracking echocardiography and feature tracking cardiac magnetic resonance (CMR), represents a useful tool in all the spectrum of cardiomyopathies. The most robust evidence available in the literature concerns cardiomyopathies with a hypertrophic phenotype, in which left atrial strain (LAS) has demonstrated to be able to differentiate each phenotype, with cardiac amyloidosis (CA) having the lowest LAS values compared to hypertrophic cardiomyopathy (HCM), Fabry cardiomyopathy (FD), and hypertensive heart disease. LAS is also able to predict the occurrence of atrial arrhythmias, in particular atrial fibrillation in CA and HCM, and major adverse cardiac event (MACE) in all the phenotypes. Interestingly, both in HCM and FD, improvement in LAS values has been detected during disease-modifying therapy. In cardiomyopathies with a dilated phenotype as well, LAS, which has been more extensively evaluated through CMR compared to other cardiomyopathies, appears to have prognostic value with respect to left ventricular reverse remodeling and the occurrence of MACE and can help to differentiate dilated cardiomyopathy from ischemic heart disease with left ventricular dilatation. Finally, in arrhythmogenic right ventricular cardiomyopathy, right atrial strain has also demonstrated prognostic power, particularly for the occurrence of both atrial and ventricular arrhythmic events. Interestingly, impaired values of right atrial strain have been detected even in the absence of dilatation of the right atrium, suggesting an earlier involvement by fibro-fatty replacement and fibrosis.