The article "Atrial Cardiomyopathy Revisited—Evolution of a Concept" is a comprehensive clinical consensus statement by the European Heart Rhythm Association (EHRA), the Heart Rhythm Society (HRS), the Asian Pacific Heart Rhythm Society (APHRS), and the Latin American Heart Rhythm Society (LAHRS). It revisits and updates the understanding of atrial cardiomyopathy (AtCM), a condition characterized by structural, architectural, contractile, or electrophysiological changes affecting the atria. The document covers recent advancements in the definition, classification, pathophysiology, imaging, biomarkers, and therapeutic implications of AtCM. Key points include: 1. **Definition and Classification**: The working definition of AtCM is broad, encompassing any complex of changes affecting the atria with potential clinical manifestations. A histological classification scheme is proposed, but it has not been widely accepted. 2. **Recent Mechanistic Insights**: Recent studies highlight the role of genetic cardiomyopathy and arrhythmia syndromes in early-onset atrial fibrillation, the prevalence of atrial amyloidosis, and the involvement of inflammatory signaling pathways such as the NLRP3 and AIM2 inflammasomes. 3. **Pathophysiology**: New findings in the pathophysiology of AtCM include the interplay between ageing, inflammation, oxidative stress, and stretch, leading to fibrosis, electrical and autonomic remodeling, and a pro-thrombotic state. 4. **Imaging Advances**: Advances in imaging tools, such as late gadolinium-enhanced cardiac magnetic resonance imaging and electroanatomic mapping, are discussed for evaluating AtCM. 5. **Biomarkers and Omics**: The role of blood-based biomarkers and multi-omics in understanding AtCM is explored, along with the potential of artificial intelligence in diagnosis and prognosis. 6. **Stroke and Cognitive Decline**: The relationship between AtCM and stroke, as well as the potential link to cognitive decline, is reviewed. 7. **Therapeutic Implications**: The document discusses primary prevention, lifestyle interventions, pharmacological therapies, rhythm control strategies, and device therapy for AtCM. The article emphasizes the need for further research and clinical trials to validate the proposed staging system and to explore the mechanisms underlying the development and progression of AtCM.The article "Atrial Cardiomyopathy Revisited—Evolution of a Concept" is a comprehensive clinical consensus statement by the European Heart Rhythm Association (EHRA), the Heart Rhythm Society (HRS), the Asian Pacific Heart Rhythm Society (APHRS), and the Latin American Heart Rhythm Society (LAHRS). It revisits and updates the understanding of atrial cardiomyopathy (AtCM), a condition characterized by structural, architectural, contractile, or electrophysiological changes affecting the atria. The document covers recent advancements in the definition, classification, pathophysiology, imaging, biomarkers, and therapeutic implications of AtCM. Key points include: 1. **Definition and Classification**: The working definition of AtCM is broad, encompassing any complex of changes affecting the atria with potential clinical manifestations. A histological classification scheme is proposed, but it has not been widely accepted. 2. **Recent Mechanistic Insights**: Recent studies highlight the role of genetic cardiomyopathy and arrhythmia syndromes in early-onset atrial fibrillation, the prevalence of atrial amyloidosis, and the involvement of inflammatory signaling pathways such as the NLRP3 and AIM2 inflammasomes. 3. **Pathophysiology**: New findings in the pathophysiology of AtCM include the interplay between ageing, inflammation, oxidative stress, and stretch, leading to fibrosis, electrical and autonomic remodeling, and a pro-thrombotic state. 4. **Imaging Advances**: Advances in imaging tools, such as late gadolinium-enhanced cardiac magnetic resonance imaging and electroanatomic mapping, are discussed for evaluating AtCM. 5. **Biomarkers and Omics**: The role of blood-based biomarkers and multi-omics in understanding AtCM is explored, along with the potential of artificial intelligence in diagnosis and prognosis. 6. **Stroke and Cognitive Decline**: The relationship between AtCM and stroke, as well as the potential link to cognitive decline, is reviewed. 7. **Therapeutic Implications**: The document discusses primary prevention, lifestyle interventions, pharmacological therapies, rhythm control strategies, and device therapy for AtCM. The article emphasizes the need for further research and clinical trials to validate the proposed staging system and to explore the mechanisms underlying the development and progression of AtCM.