CASE REPORT
Hypothermia resulting in characteristic ECG changes mimicking an acute myocardial
infarction: Osborn waves and atrial fibrillation R Evertz, KRR.
machandran,
J.P.R. Herrman, L.R. van der Wieken
Hypothemiia can cause several ECG changes which can be mistaken for other cardiac diseases, most importantly acute transmural ischaemia. These ECG changes correlate strongly with the degree of hypothermia and the prognosis of the patient. This brief report presents a 32-year-old male who was seen after a drowning accident. After resuscitation a 12-lead electrocardiogram showed changes typical for hypothermia: atrial fibrillation and Osborn waves. The ECG of the patient normalised after rewarming. (Neth Heart J 2005;13:461-3.)
normal 3.6-5.2) and mild hypercalcaemia (Ca 2.78 mmol/l, normal 2.15-2.60). A 12-lead electrocardiogram was obtained on admission, when he had a temperature of 34.9°C and showed atrial fibrillation, normal QRS interval, ST-segment elevation in leads II, III, aVF and V4 to V6 with a distinctive J wave (Osbom waves) (figure 1). After the patient had been warmed up to 35.9°C on the intensive care unit (over 24 hours after admission), the 12-lead ECG showed sinus rhythm without Osborn waves (figure 2). After extubation, he showed moderate cognitive impairment and was transferred to the ward for firrther revalidation.
Keywords: Osbom waves, hypothermia, drowning
The ECG changes, as seen in this patient, can easily be mistaken for an acute inferolateral myocardial infarction; ST elevation is present in the inferolateral leads with concomitant ST depression in I, aVR and aVL. Only the presence of Osborne waves in some complexes (arrows) points to the true cause ofthe ST changes: severe hypothermia. A mistaken diagnosis of transmural ischaemia could have led to unnecessary interventions and medications with possible additional risk. J-point elevations or Osbom waves are seen in 80 to 85% ofpatients presenting with hypothermia, with a strong correlation between the size of the Osbom waves and the degree of hypothermia.' In our patient the initial body temperature was 34.9°C, at which the Osbom waves were already seen. The Osbom waves made us doubt the initially measured body temperature; a second measurement, just minutes after the first, showed severe hypothermia of 29.60C. The temperature dropped even further, to a low of24.3°C, which can be explained by the fact that hypothermic patients lose even more heat through the airways and, in this case, the warming up had not yet been started in the emergency department. The size of the J-point elevations in this patient could be explained by the quick drop in body temperature to 24.3°C. J-point elevations or Osborn waves have been seen in normothermic patients with hypercalcaemia, acute ischaemic events, cocaine use, haloperidol overdose, left ventricular hypertrophy due to hypertension, brain injury, subarachnoid haemorrhage and cardiopulmonary arrest
A 32-year-old male presented to our emergency department after a drowning accident. He had been under water for approximately 15 minutes before divers were able to get him out. When he arrived at the hospital, the patient had already been successfully resuscitated and intubated. His Glasgow Coma scale at presentation was ElMlVtube. His pupils were isocore, wide and nonresponsive to light. His rectal temperature was initially 34.9°C, but within minutes dropped to 29.6°C. The lowest temperature measured was 24.3°C. The laboratory results showed a severe, combined metabolic and respiratory acidosis (pH 6.69, pCO2 78 mmHg, P02 173 mmHg, base excess -27.2 mmol/l, bicarbonate 9.4 mmol/l, saturation 95.5%), lactic acidosis (21.5 mmol/l, normal 0.6-2.4) with a very high anion gap (30.2 mmol/l, normal 9.0-14.0), a normal, but low potassium level (K 3.6 mmol/l, R. Evertz K.R. Ramachandran J.P.R. Herrman LR. van der Wieken Onze Lieve Vrouwe Gasthuis, Amsterdam
Correspondence to: R. Evertz Onze Lieve Vrouwe Gasthuis, PO Box 95500, 1090 HM Amsterdam E-mail: [email protected]
Netherlands Heart Journal, Volume 13, Number 12, December 2005
461
Hypothermia resulting in characteristic ECG changes mimicking an acute myocardial infarction: Osbom waves and atrial fibrillation
Figure 1. ECG on presntation with a body temperature of 34.9°C, showing atrialfibrillation and distinctive Osborn waves (arrows). 1 :' 1 :i:: ::.:! ...:li -HIzl
'J
*s-re--~t-i-:iil
-: .......... ; F::. . .'. .:;F. . . . . . . . . . . .
F . : :
7
.;
7771
-...
:
:
.:'
Figure 2. After rewarming, showing sinus rhythm and no Osborn waves.
from oversedation.2 In our patient, the calcium level was mildly elevated, but probably not enough to explain the Osbom waves. No evidence was found for any drug intoxication. Hypothermia (core body temperature
Hypothermia resulting in characteristic ECG changes mimicking an acute myocardial
infarction: Osborn waves and atrial fibrillation R Evertz, KRR.
machandran,
J.P.R. Herrman, L.R. van der Wieken
Hypothemiia can cause several ECG changes which can be mistaken for other cardiac diseases, most importantly acute transmural ischaemia. These ECG changes correlate strongly with the degree of hypothermia and the prognosis of the patient. This brief report presents a 32-year-old male who was seen after a drowning accident. After resuscitation a 12-lead electrocardiogram showed changes typical for hypothermia: atrial fibrillation and Osborn waves. The ECG of the patient normalised after rewarming. (Neth Heart J 2005;13:461-3.)
normal 3.6-5.2) and mild hypercalcaemia (Ca 2.78 mmol/l, normal 2.15-2.60). A 12-lead electrocardiogram was obtained on admission, when he had a temperature of 34.9°C and showed atrial fibrillation, normal QRS interval, ST-segment elevation in leads II, III, aVF and V4 to V6 with a distinctive J wave (Osbom waves) (figure 1). After the patient had been warmed up to 35.9°C on the intensive care unit (over 24 hours after admission), the 12-lead ECG showed sinus rhythm without Osborn waves (figure 2). After extubation, he showed moderate cognitive impairment and was transferred to the ward for firrther revalidation.
Keywords: Osbom waves, hypothermia, drowning
The ECG changes, as seen in this patient, can easily be mistaken for an acute inferolateral myocardial infarction; ST elevation is present in the inferolateral leads with concomitant ST depression in I, aVR and aVL. Only the presence of Osborne waves in some complexes (arrows) points to the true cause ofthe ST changes: severe hypothermia. A mistaken diagnosis of transmural ischaemia could have led to unnecessary interventions and medications with possible additional risk. J-point elevations or Osbom waves are seen in 80 to 85% ofpatients presenting with hypothermia, with a strong correlation between the size of the Osbom waves and the degree of hypothermia.' In our patient the initial body temperature was 34.9°C, at which the Osbom waves were already seen. The Osbom waves made us doubt the initially measured body temperature; a second measurement, just minutes after the first, showed severe hypothermia of 29.60C. The temperature dropped even further, to a low of24.3°C, which can be explained by the fact that hypothermic patients lose even more heat through the airways and, in this case, the warming up had not yet been started in the emergency department. The size of the J-point elevations in this patient could be explained by the quick drop in body temperature to 24.3°C. J-point elevations or Osborn waves have been seen in normothermic patients with hypercalcaemia, acute ischaemic events, cocaine use, haloperidol overdose, left ventricular hypertrophy due to hypertension, brain injury, subarachnoid haemorrhage and cardiopulmonary arrest
A 32-year-old male presented to our emergency department after a drowning accident. He had been under water for approximately 15 minutes before divers were able to get him out. When he arrived at the hospital, the patient had already been successfully resuscitated and intubated. His Glasgow Coma scale at presentation was ElMlVtube. His pupils were isocore, wide and nonresponsive to light. His rectal temperature was initially 34.9°C, but within minutes dropped to 29.6°C. The lowest temperature measured was 24.3°C. The laboratory results showed a severe, combined metabolic and respiratory acidosis (pH 6.69, pCO2 78 mmHg, P02 173 mmHg, base excess -27.2 mmol/l, bicarbonate 9.4 mmol/l, saturation 95.5%), lactic acidosis (21.5 mmol/l, normal 0.6-2.4) with a very high anion gap (30.2 mmol/l, normal 9.0-14.0), a normal, but low potassium level (K 3.6 mmol/l, R. Evertz K.R. Ramachandran J.P.R. Herrman LR. van der Wieken Onze Lieve Vrouwe Gasthuis, Amsterdam
Correspondence to: R. Evertz Onze Lieve Vrouwe Gasthuis, PO Box 95500, 1090 HM Amsterdam E-mail: [email protected]
Netherlands Heart Journal, Volume 13, Number 12, December 2005
461
Hypothermia resulting in characteristic ECG changes mimicking an acute myocardial infarction: Osbom waves and atrial fibrillation
Figure 1. ECG on presntation with a body temperature of 34.9°C, showing atrialfibrillation and distinctive Osborn waves (arrows). 1 :' 1 :i:: ::.:! ...:li -HIzl
'J
*s-re--~t-i-:iil
-: .......... ; F::. . .'. .:;F. . . . . . . . . . . .
F . : :
7
.;
7771
-...
:
:
.:'
Figure 2. After rewarming, showing sinus rhythm and no Osborn waves.
from oversedation.2 In our patient, the calcium level was mildly elevated, but probably not enough to explain the Osbom waves. No evidence was found for any drug intoxication. Hypothermia (core body temperature
