Operated Atrial Septal Defect Associated With Dilated Coronary Sinus in an Adult Female: Case Report & Literature Review

While uncommon in individuals without heart conditions, the coronary sinus (CS) is frequently observed during echocardiography in those with right-sided cardiac disorders. The frequency of this occurrence and its connection to right-sided heart anatomy and pressure levels remain unclear. A widened coronary sinus in an adult woman is often an accidental discovery. Studies repeatedly highlight Persistent Left Superior Vena Cava (PLSVC) draining into the CS as the most prevalent congenital abnormality. Additional significant causes encompass elevated right atrial pressure and coronary arteriovenous fistulas. Most individuals with an enlarged CS, particularly those with PLSVC, exhibit no symptoms and maintain normal life expectancy. Nevertheless, an exact diagnosis is essential if the patient undergoes invasive treatments. We are detailing a 47-year-old woman who underwent surgery for a large secundum atrial septal defect (ASD) in March 2025. During a standard follow-up transthoracic echocardiogram (TTE), we also identified an enlarged CS alongside an in-situ ASD patch without any residual shunt.