Hypothermia electrocardiogram

Hypothermia Microchapters
Home
Patient Information
Overview
Historical Perspective
Pathophysiology
Causes
Differentiating Hypothermia from other Diseases
Epidemiology and Demographics
Risk Factors
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Hypothermia electrocardiogram On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Hypothermia electrocardiogram All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Hypothermia electrocardiogram
CDC on Hypothermia electrocardiogram
Hypothermia electrocardiogram in the news
Blogs on Hypothermia electrocardiogram
Directions to Hospitals Treating Hypothermia
Risk calculators and risk factors for Hypothermia electrocardiogram

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Hypothermia is characterized on the EKG by sinus bradycardia, PR prolongation, QT prolongation, QRS prolongation and Osborn waves.

Electrocardiogram

Rate

There is a slowing of the sinus rate.

Rhythm

About 50 to 60% of these patients develop atrial fibrillation. VF may also occur.

PR Interval

There is prolongation of the PR interval.

QRS Interval

There is prolongation of the QRS which is often due to the appearance of the J wave

QT Interval

There is prolongation of the QT interval

Osborn Waves

The most typical finding is the appearance of the Osborne J wave, an extra deflection between the QRS complex and the T wave. Osborn waves are positive deflections occurring at the junction between the QRS complex and the ST segment, where the S point, also known as the J joint, has a myocardial infarction-like elevation. Osborn waves are more prominent in the left precordial leads. They increases in size with decreasing temperature. They are caused by a current of injury, delayed ventricular depolarization, or early repolarization.

Osborn waves may first appear on the ECG for temperatures less tahn 91.4 degrees Fahrenheit (33 degrees Celsius), and consistently appear when when the temperature falls below 25 degrees Centigrade.

There is variability in the morphology of Osborn waves as all J wave deflections do not look alike. Some Osborn waves are merely elevations of ST segments in leads V₁ and V₂, whereas others are of the "spike-and-dome" variety. Given the variability in morphology, a variety of mechanisms may be responsible for the size and shape of J wave deflections.

Shown below is an example of the "spike and dome" variant of the Osborn wave:

An Osborn J wave

Shown below is an Osborn wave in an 81-year-old male with a core temperature 89.5 degrees F (31.94 C):

---

Electrocardiographic Examples

Examples of Osborn Waves in the Setting of Hypothermia

Shown below is the 12 lead ECG of a patient with a body temperature of 32 degrees Celsius. Note the sinus bradycardia, the prolonged QT interval (QTc is not prolonged) and the Osborn J wave, most prominently in leads V2-V5:

---

Shown below is An ECG of a patient with a body temperature of 28 degrees Celsius:

---

Shown below are Osborn J waves due to hypothermia:

---

Shown below are Osborn J waves due to hypothermia: