  Automatic diagnosis of multiple cardiac abnormalities from reduced-lead
electrocardiogram (ECG) data is challenging. One of the reasons for this is the
difficulty of defining labels from standard 12-lead data. Reduced-lead ECG data
usually do not have identical characteristics of cardiac abnormalities because
of the noisy label problem. Thus, there is an inconsistency in the annotated
labels between the reduced-lead and 12-lead ECG data. To solve this, we propose
deep neural network (DNN)-based ECG classifier models that incorporate
DivideMix and stochastic weight averaging (SWA). DivideMix was used to refine
the noisy label by using two separate models. Besides DivideMix, we used a
model ensemble technique, SWA, which also focuses on the noisy label problem,
to enhance the effect of the models generated by DivideMix. Our classifiers
(ami_kagoshima) received scores of 0.49, 0.47, 0.48, 0.47, and 0.47 (ranked
9th, 10th, 10th, 11th, and 10th, respectively, out of 39 teams) for the
12-lead, 6-lead, 4-lead, 3-lead, and 2-lead versions, respectively, of the
hidden test set with the challenge evaluation metric. We obtained the scores of
0.701, 0.686, 0.693, 0.693, and 0.685 on the 10-fold cross validation, and
0.623, 0.593, 0.606, 0.612, and 0.601 on the hidden validation set for each
lead combination.
