Herb Hultgren in Peru: what causes high altitude pulmonary edema?

Herbert Hultgren, a cardiologist who kept a careful diary all his career, arrived in Peru at the beginning of 1959 to study the occurrence of pulmonary hypertension in children at high altitude with patent ductus arteriosus. There, he was told about a strange condition, high altitude pulmonary edema (HAPE), and found that to Peruvian physicians looking after mine employees and their families, its occurrence was almost routine. With his Peruvian colleagues, Herb immediately began a systematic study of the condition, including catheter studies. Though the absence of left ventricular enlargement suggested a non-cardiac form of pulmonary edema, and though this is what he suggested in his first publication, in two subsequent papers, one written with Charles Houston, who contributed cases occurring in mountaineers, Herb wrote that the most probable cause was left ventricular failure. What is extraordinary is that before he finally submitted the two papers, he had certain knowledge that in one case of HAPE at least, left atrial pressure had been shown to be normal. Herb's contributions, then and later, to the elucidation of HAPE were enormous.