Cutoff values of the parameters
In our retrospective study, the
cutoff
values of V2S/V3R and the V3 R-wave deflection were the same as those in
previous studies. However, compared with Nikoo et
al.[10],
the
larger
ISA
in
V1 and V2 (66.53 ±59.73 vs. 29.48 ±55.57) and the cutoff value of ISA
(57
vs.15, P = 0.00) in our study were larger. After reviewing the data
obtained from the previous study, we found that the duration
of
the R-wave in V1 (67.34 ±35.38 vs. 49.75 ±31.02) and V2 (71.09 ±25.26
vs. 53.08 ±27.72) and the amplitude of R-wave in V1 (0.38 ±0.31 vs. 0.20
±0.26) and V2 (0.79 ±0.51 vs. 0.35 ±0.47) in our study were larger. This
may be related to the inclusion of more patients
with
a transition lead in V1 (21.00% vs.10.00%) in our study. However,
after excluding 21 patients with a transition lead in V1, the ISA
(42.50 ±31.56 vs. 29.48 ±55.57) in our study was still larger than that
in the previous study; the cutoff value remained unchanged
(cutoff
value = 57 and Youden index = 0.49). In addition, with a cutoff value of
57 in our validation study, we achieved satisfactory diagnostic accuracy
(94.00%) and AUC (0.95), with a sensitivity of 97.06%, a specificity
of 92.42%, a PPV of 86.84%, and an NPV of 98.39% (Table 4).
Therefore, we believe that a cutoff value of 57 is more appropriate.