Atrial Cardiomyopathy: Pathophysiology, Diagnostic Approaches, and Prognostic Implications—A Narrative Review

Atrial cardiomyopathy (ACM) is defined as any complex of structural, architectural, functional, electrophysiological, and molecular changes affecting the atria that may result in clinically significant health consequences. ACM can be caused by a variety of factors, including age-related changes, valvular or vascular disease, genetic diseases, congestive heart failure, metabolic diseases, cardiovascular disease (CVD) risk factors such as arterial hypertension (AH) or obesity, obstructive sleep apnea, and other infectious or noninfectious diseases predisposing to chronic inflammation. The diagnosis of ACM relies on several modalities, including electrocardiography, echocardiography, cardiac magnetic resonance imaging (MRI), computed tomography (CT), electroanatomical mapping (EAM), genetic studies, and biomarkers, which can detect and characterize structural, mechanical, and electrical atrial dysfunction. These changes often include structural atrial remodeling (fibrosis), abnormal structure of the atrial wall and its components, and contractile and electrical dysfunctions. When assessing aspects of ACM, structural changes in the atria such as left atrium (LA) size and fibrosis; LA architectural changes such as the expression of remodeling; changes in LA mechanics such as echocardiographic stress indices; changes in reservoir function and changes in contraction; biological factors determining changes in biomarkers; possible genetic predispositions and higher expression of certain genes encoding certain proteins; and arrhythmogenic factors associated with a higher risk of atrial fibrillation (AF) and stroke and a worse short- and long-term prognosis are very important. When considering the challenges of diagnosing ACM, it should be noted that without standardized diagnostics, most ACM diagnostic situations remain primarily research tools rather than practical clinical diagnostic methods. This review critically evaluates the evidence and translational gaps in the diagnosis of ACM, synthesizing the emerging role of advanced diagnostics and their clinical and prognostic implications as a key future tool for individual risk stratification.