Where the ST segment is horizontal it is fairly straightforward to identify where the S-wave finishes and the ST segment begins but a sloping ST segment can cause more difficulty but the J-point can usually be identified by the change in gradient.
It is fairly straightforward to identify where the S-wave finishes. The ST segment is horizontal. The ST segment begins. A sloping ST segment can cause more difficulty but the J. Point can usually be identified by the change in gradient.