This term marks the boundary between the end of the QRS and the beginning of the ST segment.

This term marks the boundary between the end of the QRS and the beginning of the ST segment.

• A. J point
• B. P point
• C. Q point
• D. T point

Answer: (A)

The boundary between the end of the QRS and the beginning of the ST segment is defined by the J point. The J point marks where the QRS complex finishes and the ST segment begins, with the ST segment extending from there up to the onset of the T wave. Clinically, ST changes are assessed starting at the J point relative to the baseline, which is why this point is key for detecting ST elevation or depression. The P wave occurs before the QRS and is not involved in marking this boundary, the Q point relates to the start of the QRS deflection rather than the end of it, and the T point is associated with the terminal part of the T wave rather than the transition from QRS to ST.

The boundary between the end of the QRS and the beginning of the ST segment is defined by the J point. The J point marks where the QRS complex finishes and the ST segment begins, with the ST segment extending from there up to the onset of the T wave. Clinically, ST changes are assessed starting at the J point relative to the baseline, which is why this point is key for detecting ST elevation or depression. The P wave occurs before the QRS and is not involved in marking this boundary, the Q point relates to the start of the QRS deflection rather than the end of it, and the T point is associated with the terminal part of the T wave rather than the transition from QRS to ST.