UNPREDICTABLE RESPONSE TO VASODILATOR THERAPY IN PRIMARY PULMONARY-HYPERTENSION

A 49-year-old man with severe primary pulmonary hypertension unrespons ive to multiple vasodilators showed beneficial response to intravenous (i.v.) isoproterenol with significant decrease in the pulmonary vascu lar resistance and increase in the cardiac output. However, the patien t became dependent on i.v. isoproterenol and eventually died suddenly following an episode of bradyarrhythmia. Autopsy confirmed severe prim ary pulmonary hypertension. As the response to vasodilator therapy can be unpredictable in PPH, sequential hemodynamic evaluation of drugs i s necessary for finding an optimal therapeutic agent.