Pulmonary Hypertension: Beyond the Swan Ganz Catheter

Serotonin Antagonists• 32 patients, 16 with PPH and 16 normal controls, measured platelet andplasma serotonin levels during in vitro platelet aggregation• Patients had decreased platelet serotonin concentration (P < 0.01) andincreased plasma serotonin concentration (P < 0.001)• Abnormal handling of serotonin by platelets ‐> increased plasmaserotonin• Abnormalities persist even after PHTN resolves• Six patients were restudied after heart‐lung transplantation todetermine whether serotonin abnormalities persisted after pulmonaryarterial pressure returned to normal.• Platelet serotonin concentrations remained decreased and plasmalevels remained increased.• Not secondary to PPHHerve, et al. (1995). American Journal of Medicine, 99(3), pp. 249‐254.