Beyond the murmur: unmasking a rare sinus venosus ASD in an adolescent with chronic respiratory infections: A case report.

RATIONALE: Overall, 5% to 10% of all atrial septal defects (ASDs) are of the sinus venosus type, a rare congenital disease. This defect must be identified and treated immediately since it might cause significant left atrial dilatation and dyspnea. PATIENT CONCERNS: A 15-year-old male presented with previously undetected sinus venosus type ASD. The patient arrived with a high-grade heart murmur and a history of recurring respiratory illnesses. DIAGNOSES: A clinical examination identified a 3/6 systolic ejection murmur in the second left intercostal gap and a fixed split second heart sound. Electrocardiography revealed sinus rhythm with partial right bundle branch block, while echocardiography indicated considerable enlargement of the right atrium and right ventricle, accompanied by a D-shaped left ventricle. A sinus venosus type ASD with an inferior vena cava-right atrial shunt was verified. INTERVENTIONS: The patient had surgical closure of the defect via midline sternotomy, thereafter gaining access to the right atrium and performing pericardial patch repair. OUTCOMES: Two months postoperatively, the patient's right ventricular diameters and pulmonary artery pressures were significantly diminished (25-30 mm Hg), and his overall status was excellent. LESSONS: Sinus venosus type ASD is an infrequent etiology of persistent respiratory problems in adolescents. Early detection by thorough clinical and echocardiographic assessment, followed by timely surgical intervention, may lead to superior functional recovery and improved long-term quality of life.