1 Sleep Laboratory, Bethesda North Hospital, Cincinnati, OH; University of Cincinnati, Cincinnati, OH; Division of Cardiology, The Ohio State University, Columbus, OH. Electronic address: [email protected].
2 Respiratory Department, Hospital de Valme, IBiS, Sevilla, Spain; CIBERES, Instituto de Salud Carlos III, Madrid, Spain.
3 Respiratory Department, University and polytechnic La Fe Hospital, Valencia, Spain.