A 60 year old gentleman presents with shortness of breath. Interestingly, his dyspnea is worse while upright and relieved while lying down. He has been out of care for a long time and does not know his past medical history. He takes no medications, has no known allergies, and does not know his family history. His social history is significant for being homeless, having a 40 year heavy drinking history, smoking 50 pack-years, and trying pretty much "any recreational drug invented."
Physical exam shows an O2 sat of 85%. This worsens while he is sitting and improves while he is lying down. You also notice these findings on his skin:An arterial blood gas on room air shows a PaO2 of 60mmHg. Your attending, after evaluating the patient, says, "I bet at rest, he has an elevated cardiac output, perhaps even up to 7L/min.
Challenge: What is this syndrome called?
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