title: The cardiovascular effects of acute hypoxemia as a diagnostic aid.
abstract: Acute hypoxemia produces opposite effects on the pulmonary and systemic vascular resistance. To assess the influence of acute hypoxemia on cardiac murmurs, 36 patients with a single valvular or congenital heart lesion were studied. As expected from these hemodynamic effects, right-sided regurgitant type murmurs increased in intensity during acute hypoxemia, while stenotic type murmurs were reduced. In contrast, left-sided murmurs remained constant or changed in opposite direction to their equivalent type from the right side. Additionally, acute hypoxemia produced a marked reduction of the murmurs due to left-to-right shunts and allowed an adequate differentiation of the murmurs due to ventricular septal defect from those due to mitral incompetence.
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006326:Heart Auscultation; D006337:Heart Murmurs; D006349:Heart Valve Diseases / Q000151:congenital / Q000175:diagnosis*; D006801:Humans; D000860:Hypoxia / Q000139:chemically induced*; D008297:Male; D009584:Nitrogen; D010100:Oxygen; D010701:Phonocardiography; D011652:Pulmonary Circulation / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D009584:Nitrogen; D010100:Oxygen