J point and J wave in ECG, How to recognise J point скачать в хорошем качестве

J point and J wave in ECG, How to recognise J point

ent things. The J point is the junction between the QRS complex (depolarization) and the ST segment (early repolarization) and is present on every ECG. A J wave, also known as an Osborn wave, is a distinct positive deflection on the ECG following the QRS complex, and it is much less common than the J point. J Point: Definition: The J point marks the end of ventricular depolarization and the beginning of ventricular repolarization. Location: It's the point where the S wave (or R wave if there's no S wave) transitions into the ST segment. Significance: It is a reference point for measuring ST segment elevation or depression, which can indicate myocardial infarction (heart attack) or other conditions. Normal Appearance: The J point is often at the same level as the PR segment (baseline), but can be slightly elevated, especially in young, healthy individuals. J Wave (Osborn Wave): Definition: A positive deflection on the ECG following the QRS complex, appearing as a hump or dome. Appearance: It has the same polarity as the preceding QRS complex. Significance: Primarily associated with hypothermia (low body temperature). Also seen in other conditions, including hypercalcemia, brain injury, Brugada syndrome, and some forms of ventricular fibrillation. Clinical Relevance: While often benign, J waves can be a marker of increased risk for ventricular arrhythmias in some contexts. Distinction from Terminal Notch: A terminal notch on the QRS complex can also appear similar to a J wave, but it is usually sharper and is associated with intraventricular conduction defects, structural heart disease, and tachycardia. In summary: The J point is a normal ECG landmark, while the J wave is a less common, distinct wave, often associated with hypothermia and other conditions, which may or may not be clinically significant.