The “J wave” (also referred to as “the Osborn wave,” “the J deflection,” or “the camel’s hump”) is a distinctive deflection occurring at the QRS-ST junction. In 1953, Dr. John Osborn described the “J wave” as an “injury current” resulting in ventricular fibrillation during experimental hypothermia.
What causes an Osborn wave?
J waves, also known as Osborn waves or the camel-hump sign, can be caused by hypercalcemia, brain injury, subarachnoid hemorrhage, and cardiopulmonary arrest from oversedation, vasospastic angina, or ventricular fibrillation. However, the chief cause is hypothermia (body temperature,
Where does an Osborn wave appear on an ECG reading?
The Osborn wave is a deflection with a dome or hump configuration occurring at the R-ST junction (J point) on the ECG (Figure 1).
What is J point depression?
Elevation or depression of the J point is seen with the various causes of ST segment abnormality. It may be elevated as a result of injury currents during acute myocardial ischemia and pericarditis, as well as in various other patterns of both normal and abnormal ECGs.
What is early repolarization ECG?
Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and
What does J point elevation mean?
The term J-point elevation represents a family of ECG findings. It has been described in several metabolic disorders most notably hypothermia (abnormally low body temperature). Subtle nuances in its pattern may point to other conditions, the most common of which is termed ‘early repolarization’.
Are J waves normal?
J-point elevations and J-waves/early repolarization in athletes. These patterns have been observed in routine ECG recordings from asymptomatic athletes for many years and have been considered to be normal variants. It is still generally accepted that the most are indeed benign.
How do you identify a pathological Q wave?
Q waves are considered pathological if:
> 40 ms (1 mm) wide.> 2 mm deep.> 25% of depth of QRS complex.Seen in leads V1-3.
What happens during ST segment?
The ST segment reflects the midportion, or phase 2, of repolarization during little change in electrical potential. It is usually isoelectric. Ischemia causes a loss of intracellular potassium, resulting in a current of injury. With subendocardial injury, the ST segment is depressed in the surface leads.
What temperature is hypothermia?
Overview. Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 98.6 F (37 C). Hypothermia (hi-poe-THUR-me-uh) occurs as your body temperature falls below 95 F (35 C).
What does electrical alternans indicate?
Electrical alternans. This electrocardiogram shows ventricular tachycardia from the right ventricular outflow tract (RVOT) region. Note the R wave alternans seen in the wide QRS complexes. The presence of micro-T wave alternans may indicate a higher risk of sudden cardiac death and spontaneous ventricular arrhythmias.
Why does digoxin cause ST depression?
Shortening of the atrial and ventricular refractory periods — producing a short QT interval with secondary repolarisation abnormalities affecting the ST segments, T waves and U waves.
What does J point indicate?
Introduction. The J point denotes the junction of the QRS complex and the ST segment on the electrocardiogram (ECG), marking the end of depolarization and beginning of repolarization.
What does STJ level mean?
Key definitions
STEMI (ST elevation myocardial ischemia/infarction) STJ level (ST level at J point, QRS end) STEMI imposter (non-ischemic cause of ST elevation) Sensitivity for STEMI.
What does an elevated ST segment indicate?
ST-segment elevation usually indicates a total blockage of the involved coronary artery and that the heart muscle is currently dying. Non-STEMI heart attacks usually involve an artery with partial blockage, which usually does not cause as much heart muscle damage.
Is early repolarization good?
Early repolarization, ST-segment elevation in the absence of conduction abnormalities, or chest pain has been considered as a normal state for more than half a century. Because this ECG pattern predominates among young and fit individuals with slow heart rates, it has been generally viewed as a marker of good health.
Should I be worried about early repolarization?
Studies showed that patients with early repolarization pattern, found in the inferior leads, have a higher risk of mortality and sudden cardiac death. In patients aged older than 50 years, mortality between groups with and without early repolarization pattern additionally separates.
What are the symptoms of early repolarization?
Patients with ERP generally do not have any noticeable physical symptoms. The main characteristic associated with the condition is an abnormal pattern on the EKG image. Patients with ERP also often have a lower baseline heart rate.
