J-Point — ECG/EKG Terminology

Definition: The junction point where the QRS complex ends and the ST segment begins.

Key Facts

• Transition point between QRS termination and ST segment onset.
• Used as reference for evaluating ST elevation or depression.
• Can be physiologically elevated in benign early repolarization patterns.

ECG Connection: Accurate J-point identification is required for ischemia and STEMI interpretation.

Why It Matters: Misidentifying the J point can lead to over- or under-calling acute coronary events.