Inferior vena cava anomalous drainage into the left atrium with severe pulmonary arterial hypertension: a case report and review of management strategies.

Anomalous drainage of the inferior vena cava (IVC) into the left atrium is a rare congenital anomaly seldom associated with pulmonary arterial hypertension (PAH). This condition may correlate with atrial septal defect (ASD), pulmonary arteriovenous fistula, and chronic hypoxemia. We present a case of a 34-year-old female admitted with recurrent chest tightness, dyspnea, and palpitations. Comprehensive evaluations, including transthoracic echocardiography, computed tomography angiography, and right heart catheterization, confirmed the diagnosis of IVC anomalous drainage into the left atrium complicated by ASD (about 3 cm), right inferior pulmonary vein anomalous drainage into the inferior vena cava, and severe PAH. Following multidisciplinary consultation, a combined "treat and repair" strategy was adopted, initiating targeted PAH therapy with ambrisentan and sildenafil. At the 3-month follow-up, the patient reported significant symptomatic improvement, resumed daily physical activities without cardiorespiratory discomfort, PASP decreased from 146 mmHg to 127 mmHg and demonstrated enhanced functional capacity. This case highlights the diagnostic challenges and therapeutic considerations for IVC anomalies associated with PH, contributing novel insights to the management of complex congenital cardiovascular disorders.