Atrial secondary mitral regurgitation (ASMR) and atrial secondary tricuspid regurgitation (ASTR) differ from ventricular secondary mitral regurgitation (VSMR) and ventricular secondary tricuspid regurgitation (VSTR). Unlike VSMR/VSTR, which is caused by ventricular remodelling, ASMR/ASTR is primarily a result of atrial remodelling. This distinction is crucial for diagnosis and treatment. Echocardiography is the initial diagnostic tool for both conditions. Key features of ASMR and ASTR include severe atrial dilatation, annulus dilatation, central regurgitation jet and normal ventricular systolic function and size. Treatment for ASMR and ASTR includes medical therapy for underlying conditions, such as atrial fibrillation and heart failure with preserved ejection fraction. Sodium-glucose transporter 2 inhibitors and angiotensin receptor blockers may induce reverse remodelling and modulate profibrotic changes. Management of underlying atrial cardiomyopathy is crucial in ASMR and ASTR. Restoration of sinus rhythm through cardioversion or catheter ablation is key, as it can lead to reverse remodelling of the atria and annuli, thereby reducing regurgitation severity. Surgical or transcatheter interventions should be considered in patients with severe symptoms despite medical therapy and restoration of sinus rhythm.