J point
The J point The J point is the the junction between the termination of the QRS complex and the beginning of the ST segment. The J (junction) point in the ECG is the point where the QRS complex joins the ST segment. It represents the approximate end of depolarization and the beginning of repolarization as determined by the surface ECG. There is an overlap of around 10ms. The J point marks the end of the QRS complex, and is often situated above the baseline, particularly in healthy young males. The J point may deviate from the baseline in early repolarization, epicardial or endocardial ischaemia or injury, pericarditis, RBBB, LBBB, RVH, LVH or digitalis effect. ...