Osborne waves in ECG are seen in :
**Core Concept**
Osborne waves, also known as J waves, are a type of abnormality observed in the electrocardiogram (ECG) of patients with hypothermia. They are characterized by an elevated J point, which is the junction between the QRS complex and the ST segment.
**Why the Correct Answer is Right**
Osborne waves occur due to the slowing of conduction in the myocardium, which leads to an increased action potential duration and an elevated J point. This is a result of the cold-induced slowing of ion channel function, particularly the potassium channels, which prolong the action potential duration and lead to the characteristic J wave.
**Why Each Wrong Option is Incorrect**
**Option A:** Not applicable.
**Option B:** While hypocalcemia can cause a variety of ECG abnormalities, it is not typically associated with Osborne waves.
**Option C:** Hyperkalemia can cause a variety of ECG abnormalities, including changes in the ST segment and QRS complex, but it is not typically associated with Osborne waves.
**Clinical Pearl / High-Yield Fact**
Osborne waves are a classic ECG finding in hypothermia, and their presence should prompt a search for underlying hypothermic conditions, such as exposure to cold water or environmental hypothermia.
**Correct Answer: C. Hypothermia.**