Circulation. 2000;101:e233-e244
(Circulation. 2000;101:e233.)
© 2000 American Heart Association, Inc.
Circulation Electronic Pages |
Osborn Waves of Hypothermia
Imad A. Alhaddad, MD;
Mohammed Khalil, MD;
Edward J. Brown, Jr, MD
From the Cardiology Division, Department of Medicine, Bronx Lebanon
Hospital Center, Bronx, NY.
Correspondence to Imad A. Alhaddad, MD, Division of Cardiology, Department of Medicine, Bronx Lebanon Hospital Center, 1650 Grand Concourse, Bronx, New York, NY 10457. E-mail alhaddad{at}pol.net
 |
Introduction
|
|---|
 Top
 Introduction
|
|---|
A12-lead ECG was
obtained from a 72-year-old man with a core
body temperature of 85°F
(Figure 1
). The ECG shows severe
sinus
bradycardia with prolonged PR, prolonged QRS complex,
prolonged QT
interval, and an extra deflection at the end of
the QRS complex (Osborn
waves) (arrows). A second 12-lead ECG
obtained 24 hours later, after
the patient had been rewarmed
to 98°F, was normal (Figure 2
).
View larger version (102K):
[in this window]
[in a new window]
|
Figure 1. A 12-lead ECG obtained at core body temperature of
85°F. Note Osborn waves, an extra deflection at end of QRS complex
(arrows).
|
|
Hypothermia, defined as core body temperature <95°F, is
associated with ECG changes of diagnostic and prognostic
importance. In the initial stages of hypothermia, a sinus
tachycardia develops as part of the general stress
reaction. As the temperature drops below 90°F, a sinus bradycardia
supervenes, associated with progressive prolongation of the PR
interval, QRS complex, and QT interval. With temperature approaching
86°F, atrial ectopic activity is often noted and can progress to
atrial fibrillation. At this level of hypothermia, 80% of patients
have Osborn waves that consist of an extra deflection at the end of the
QRS complex.
Osborn waves, also known as J waves, camel-hump waves, and hypothermic
waves, are best seen the inferior and lateral
precordial leads. They become more prominent as the body
temperature drops, and they regress gradually with rewarming.
With temperature <86°F, a progressive widening of the QRS complex
increases the risk of ventricular fibrillation. When the
temperature drops to 
60°F, asystole
supervenes.
|
Footnotes
|
|---|
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister,
Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal
Hospital and Texas Heart Institute, and Clinical Professor of
Pathology, University of Texas Medical School and Baylor College
of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.
