Pulmonary hypertension due to high cardiac output

Pulmonary hypertension (PH) is usually associated with a normal or decreased cardiac output (CO). Less commonly, PH can occur in the context of a hyperdynamic circulation, characterized by high CO (>8 L/min) and/or cardiac index ≥4 L/min/m² in the setting of a decreased systemic vascular resistance. PH due to high CO can occur due to multiple conditions and in general remains understudied. In this review article we describe the pathophysiology, etiology, diagnosis, hemodynamic characteristics, and management of PH in the setting of high CO. It is important to recognize this distinct entity as PH tends to improve with treatment of the underlying etiology and PH specific therapies may worsen the hemodynamic state.