Grading estimation can be based on DMLd prolongation (1.26 - 2.35ms: grade 1, 2.36 - 4.13ms: grade 2, ³ 4.13ms: grade 3 and no responsibility: grade 4) or DSLd prolongation (0.8 - 1.59: ms: grade 1, 1.6 - 2.66ms: grade 2, ³ 2.66ms: grade 3 and no responsibility: grade 4).