Pulmonary arterial pulsus alternans secondary to primary pulmonary hypertension.

Pulsus alternans of the pulmonary artery without systemic pulsus alternans is uncommon and is associated with multiple diseases. Two cases of pulmonary hypertension with pulmonary arterial pulsus alternans and right-sided heart failure are described. Primary pulmonary hypertension was demonstrated at autopsy in both cases. These two case reports constitute another previously unreported cause for pulsus alternans in the pulmonary circuit.