About the identification of class F

[PGCJ]

Hello author, may I ask why class F is so difficult to identify? I have tried a lot of methods, as well as the code on github, basically have difficulty recognizing F, but which do not open source code can be recognized and recall is also high.

[andrelopes2001]

Look into the theory behind what is supposed to be labeled as F, S and V. F is the fusion of ventricular and normal beats.