Left and Right Atrial Strain Across the Heart Failure Continuum: Multifaceted Markers of Subclinical Mechanical...

Heart failure (HF) is increasingly recognized as a progressive syndrome that begins long before patients develop clinical signs or symptoms, during which conventional echocardiographic parameters may fail to detect early myocardial impairment. Atrial strain imaging by speckle-tracking echocardiography has emerged as a sensitive, non-invasive tool capable of identifying subtle functional abnormalities before symptoms or structural remodeling occur. Impaired left atrial (LA) reservoir strain (LASr) serves as a sensitive marker of left ventricular (LV) diastolic dysfunction with elevated filling pressures, exercise intolerance, and HF with preserved ejection fraction, with incremental diagnostic or prognostic value reported in selected studies. Reduced LA strain is also strongly associated with atrial fibrillation (AF), valvular heart disease progression, adverse outcomes following myocardial infarction, and pulmonary vascular involvement. Although comparatively less studied, right atrial (RA) reservoir strain (RASr) reflects the haemodynamic burden of the right heart, right ventricular-pulmonary arterial coupling, and early subclinical dysfunction in cardiometabolic disease, pulmonary hypertension, and established HF. Similarly, RA strain has demonstrated potential diagnostic and prognostic value across the HF spectrum. This review summarizes contemporary evidence regarding the pathophysiological, diagnostic, and prognostic significance of LASr and RASr in unveiling subclinical dysfunction in HF. Both LA and RA strain may provide complementary information on atrioventricular coupling and may identify functional impairment and increased haemodynamic burden before overt structural remodeling becomes evident. Atrial strain assessment may therefore complement conventional echocardiography in the early detection, phenotypic characterization, and risk stratification of patients across different stages of HF.