A rare case of large aortopulmonary window with Eisenmenger syndrome and adult survival.

Patients with polycythemia have an abnormally elevated hemoglobin, hematocrit, and red cell count. It is important to differentiate primary polycythemia from secondary causes since this can affect patient management and prognosis. We report the case of a young male, suspected to have primary polycythemia who was referred for a cardiology opinion after a bone marrow examination was normal and testing for Janus kinase gene mutation was negative. Presence of central cyanosis and clubbing, clinical evidence of severe pulmonary artery hypertension, and significant hypoxemia on arterial blood gas analysis suggested that the polycythemia was secondary to an intracardiac shunt. Transthoracic and contrast echocardiography revealed a large aortopulmonary window with right-to-left shunting. A 64-slice cardiac computed tomography imaging confirmed the diagnosis. In the developing world, it is not uncommon to encounter such unusual cases; careful attention to basic clinical signs and use of multimodality imaging are helpful in establishing the correct diagnosis. <Learning objective: Clinicians should be aware that it is important to distinguish between primary and secondary polycythemia. Although Eisenmenger syndrome is rare in the West, it is not uncommon to encounter such cases in the developing world. Since such patients are polycythemic, they often undergo unnecessary hematological investigations as happened in our case. Careful attention to basic clinical signs and a systematic approach with multimodality imaging were helpful in establishing the diagnosis.>.