HomeCirculationVol. 123, No. 12Letter by Joynt and Edelman Regarding Article, “Iatrogenic Giant Osborn Waves” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Joynt and Edelman Regarding Article, “Iatrogenic Giant Osborn Waves” Karen E. Joynt, MD, MPH and Elazer R. Edelman, MD, PhD Karen E. JoyntKaren E. Joynt Search for more papers by this author and Elazer R. EdelmanElazer R. Edelman Search for more papers by this author Originally published29 Mar 2011https://doi.org/10.1161/CIRCULATIONAHA.110.006478Circulation. 2011;123:e390To the Editor:We read with interest the recent publication by Pavlidis et al, “Iatrogenic Giant Osborn Waves.”1 Joseph Osborn published his manuscript exploring the physiological effects of hypothermia in 1953; the ECG changes he identified in hypothermic dogs have come to be known as the J waves of Osborn. However, as we recently described, core temperature alone cannot account for the presence of Osborn waves on the ECG of patients undergoing therapeutic hypothermia.2 The appearance (and disappearance) of Osborn waves likely depends not only on hypothermia but also on abnormalities in blood pH. Indeed, in his original experiments, Osborn noted that J waves were absent in hypothermic animals in which the pH was maintained in the normal range via mechanical ventilation. Osborn wrote, “We regard this as evidence that the ECG changes … may not be associated with the low temperature directly, but rather may be more closely associated with faulty elimination of CO2 under hypothermic conditions.”3 As hypothermia becomes an increasingly common therapeutic option for survivors of cardiac arrest, subtleties in the Osborn wave may take on greater clinical relevance as indicative of not only core body temperature, but also other essential physiological parameters, especially pH.Karen E. Joynt, MD, MPH Division of Cardiovascular Medicine Brigham and Women's Hospital Boston, MAElazer R. Edelman, MD, PhD Division of Cardiovascular Medicine Brigham and Women's Hospital and Harvard Medical School Boston, MADisclosuresNone.