Purpose of review: Pleural effusions commonly occur in patients with left heart failure. However, there is increasing evidence that patients with pulmonary hypertension and isolated right heart failure frequently have pleural effusions.

Recent findings: Three recent studies have evaluated the incidence of pleural effusions without an alternate explanation in patients with idiopathic/familial pulmonary arterial hypertension (14%), pulmonary arterial hypertension associated with connective tissue diseases (33%), and portopulmonary hypertension (30%). The majority of patients in all three studies with pleural effusions without an alternate explanation were found to have isolated right heart failure.

In these studies, mean right atrial pressures and death during follow-up were significantly higher in patients with pleural effusions and isolated right heart failure compared to patients with no pleural effusions.

Summary: Pleural effusions without an alternate explanation occur commonly in at least three subtypes of pulmonary arterial hypertension. The majority of patients with pleural effusions also have isolated right heart failure that is thought to be responsible for the development of the effusions. Patients presenting with pulmonary hypertension should be evaluated for pleural effusions, and if present, should receive a work-up for right heart failure.