hypothermia, a typical sign that is going to diagnose non cardiac ailment, variants

1. OSBORN WAVE
N Venkateshwarlu MBBS (kurnool), MD(AIIMS/Lady Hardinge)
Professor,
Department of Internal Medicine
SVS Medical College Mahabubnagar A.P.

2. Osborn wave
Dr. Nandyala Venkateshwarlu
SVS Medical College

3. Osborn wave
• Osborn waves (also known as camel-hump
sign, late delta wave, hathook
junction, hypothermic wave, prominent J
wave ,[1] K wave, H wave or current of injury) are
an electrocardiogram finding.[2]
• Osborn waves are positive deflections occurring
at the junction between the QRS complex and
the ST segment,[3][4] where the S point, also
known as the J point, has a myocardial infarction-
like elevation.
Dr. Nandyala Venkateshwarlu
SVS Medical College

4. Causes
• They are usually observed in people suffering
from hypothermia with a temperature of less
than 32 C (90 F),[5] though they may also occur
in people with high blood levels
of calcium (hypercalcemia), brain injury,
vasospastic angina, or ventricular fibrillation.
Dr. Nandyala Venkateshwarlu SVS Medical College

5. Eponym
• These waves were definitively described in 1953
by John J. Osborn (born 1917) and were named
in his honor.[6] The prominent J deflection
attributed to hypothermia was first reported in
1938 by Tomaszewski. Over time, the wave has
increasingly been referred to as an Osborn wave,
in most part due to Osborn's 1953 article in the
American Journal of Physiology on experimental
hypothermia.[7]
Dr. Nandyala Venkateshwarlu
SVS Medical College

6. Historic Overview of the Osborn
Waves
• In 1953, Osborn studied the effect of hypothermia on the respiratory and
cardiac function in dogs. Experimentally-induced hypothermia caused the
development of a distinct deflection at the J point on the ECG, which he
called “current of injury”.
• Earlier than the Osborn’s description, similar deflections on the ECG had
already been described in 1920 and 1922 by Kraus [in hypercalcemic
conditions, and in 1938 by Tomashewski in a hypothermic patient.
• Although there had been several reports regarding an alternation in the
ECG at the J point prior to Osborn’s article, this deflection came to be called
the “Osborn wave” in honor of his systematic and excellent work.
• Osborn considered acidemia induced by hypothermia as a primary cause of
the Osborn wave, because it disappeared if the arterial pH was normalized
by hyperventilation during the same degree of cooling .
Dr. Nandyala Venkateshwarlu
SVS Medical College

7. Historic Overview of the Osborn
Waves
• In 1959, Emslie-Smith et al found differences in the endocardial and
epicardial responses of the ventricular myocardium to cold, and the
Osborn wave was more prominent in the epicardial than
endocardial leads.
• Also, they questioned the participation of acidosis in the genesis of
the Osborn wave on the basis of their observation that the Osborn
waves appeared in hypothermic dogs irrespective of the blood pH.
In the same year, West et al confirmed that the spike and dome
pattern could be recorded by a microelectrode technique in the
canine epicardial action potential.
• The resulting notch in the action potential was rate sensitive and
markedly accentuated under hypothermic conditions.
• Earlier studies attributed the Osborn waves to a variety of factors,
including anoxia, injury current, acidosis, delayed ventricular
depolarization and early ventricular repolarization
Dr. Nandyala Venkateshwarlu SVS Medical College

8. Historic Overview of the Osborn
Waves
• In 1988, Litovsky and Antzelevitch [proposed a difference in the
electrophysiology of the ventricular epicardium and endocardium
as the basis for the Osborn waves.
• The 4-aminopyridine sensitive transient outward current (Ito) was
shown to be prominent in canine ventricular epicardium, but not in
the endocardium. The more conspicuous notched configuration of
the epicardial action potential was supposed to produce a
transmural voltage gradient during ventricular activation that
manifested as the Osborn wave in the ECG. In 1996, Yan and
Antzelevitch [elegantly clarified their hypothesis using an arterially
perfused canine ventricular wedge model, which made it possible
to simultaneously record transmembrane action potentials from
several sites across the ventricular wall together with a transmural
ECG.
Dr. Nandyala Venkateshwarlu SVS Medical College

9. Historic Overview of the Osborn
Waves
• A highly significant correlation was shown between the amplitude of the
epicardial notch and the amplitude of the Osborn wave recorded during
several interventions, including hypothermia, premature stimulation, and
block of Ito by 4-amionopyridine.
• In other studies, they demonstrated that a hypercalcemic or ischemic
condition that had been reported to trigger the appearance of the
Osborn waves, accentuated the epicardial action potential notch.
• They had also reported that there was a difference in the
electrophysiological response of the epicardium and endocardium to
acetylcholine and isoproterenol, which might explain the occurrence of
the Osborn waves in patients with neurological disorders
Dr. Nandyala Venkateshwarlu SVS Medical College

10. Complications of hypothermia
• Cardiac arrhythmias at temperatures below 30-32°C
• Infection
• Aspiration pneumonia
• Pulmonary edema
• Pancreatitis
• Bleeding diathesis
• Bladder atony
• Frostbite
• Electrolyte (hyperkalemia, hypoglycemia), hematocrit,
coagulation study abnormalities
Dr. Nandyala Venkateshwarlu SVS Medical College

11. Complications of treatment of
hypothermia
• Rewarming shock, or hypotension secondary
to marked vasodilatation of rewarming
• Rewarming acidosis due to recirculation of
pooled lactic acid in the peripheral circulation
• Rewarming electrolyte disturbances, in
particular hypocalcemia and
hypomagnesemia, indicate a poor prognosis
• Aspiration pneumonia
• Pulmonary edema
• Pancreatitis
Dr. Nandyala Venkateshwarlu SVS Medical College

12. Complications of treatment of
hypothermia
• Burns to cold and vasoconstricted skin secondary to
application of hot water bottles and heating pads
• Neutropenia, thrombocytopenia, and infection
• Iatrogenic hyperthermia
• Ventricular fibrillation
• Peritonitis
• GI bleeding
• Acute tubular necrosis
• Intravascular thrombosis
• Metabolic acidosis
• Rhabdomyolysis
• Gangrene
• Compartment syndrome
Dr. Nandyala Venkateshwarlu
SVS Medical College

14. Osborn wave - An example of an
Osborn J wave in a hypothermic
person.
Dr. Nandyala Venkateshwarlu
SVS Medical College

15. Osborn wave
Dr. Nandyala Venkateshwarlu
SVS Medical College

16. The height of the J wave is roughly proportional to the
degree of hypothermia:
Subtle J waves in mild hypothermia (temp 32.5°C)
Dr. Nandyala Venkateshwarlu
SVS Medical College

17. J waves in moderate hypothermia
(temp 30°C)
Dr. Nandyala Venkateshwarlu
SVS Medical College

18. Marked J waves in severe
hypothermia (temp < 27°C)
Dr. Nandyala Venkateshwarlu
SVS Medical College

19. Twelve-lead ECG obtained in a 56-year-old man with a core body temperature
of 32.7º C because of accidental exposure to cold. The tracing shows sinus
bradycardia, prolonged QT intervals, a base-line artifact due to muscle
tremors and distinctive ...
Dr. Nandyala
Venkateshwarlu
SVS Medical College

21. Donald Hill,
M.D.; Frank
Gerbode,
M.D.; John J.
Osborn, M.D.;
Mogens
Bramson with
the Heart Lung
Machine
Dr. Nandyala Venkateshwarlu
SVS Medical College

22. There is very slow atrial flutter (rate = 167) with 4:1 AV conduction. There is
a wide QRS with a very large notch (in this case, a hump), or J-wave, at the
end. This is the classic Osborn wave of hypothermia.

23. There is very slow atrial flutter (rate = 167) with 4:1 AV
conduction. There is a wide QRS with a very large
notch (in this case, a hump), or J-wave, at the end. This
is the classic Osborn wave of hypothermia.
Dr. Nandyala Venkateshwarlu
SVS Medical College

24. The same patient’s earlier EKG
Dr. Nandyala Venkateshwarlu
SVS Medical College

25. The same pt – comparision
Dr. Nandyala Venkateshwarlu
SVS Medical College

26. Short ST segment (with resulting short QT
interval) of hypercalcemia mimicking Osborn
waves
Dr. Nandyala Venkateshwarlu
SVS Medical College

27. Dr. Nandyala Venkateshwarlu
SVS Medical College