I Would Like To Ask About Fragmented QRS Complexes. I

i would like to ask about fragmented QRS complexes. i read about the journal entitled : fQRS in identifying culprit lesion in NSTEMI patients. in the literature i read, NSTEMI only subendocardial infarction, that's why didnt caused depolarization disturbances (QRS complexes), only repolarization of ventricle (ST-T changes). How come? thanks for your explanation
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hope u can explain spesifically for my curiosity
best regards
Risa