Beat by Beat: Classifying Cardiac Arrhythmias with Recurrent Neural Networks
This work addresses the need for accurate and interpretable heart rhythm classification for patients at risk, using mobile cardiac event recorders, but it is incremental as it builds on existing RNN methods with novel task formulation and attention.
The paper tackled the problem of classifying cardiac arrhythmias from ECG signals by developing an ensemble of recurrent neural networks with attention, achieving a state-of-the-art average F1 score of 0.79 on an unseen test set.
With tens of thousands of electrocardiogram (ECG) records processed by mobile cardiac event recorders every day, heart rhythm classification algorithms are an important tool for the continuous monitoring of patients at risk. We utilise an annotated dataset of 12,186 single-lead ECG recordings to build a diverse ensemble of recurrent neural networks (RNNs) that is able to distinguish between normal sinus rhythms, atrial fibrillation, other types of arrhythmia and signals that are too noisy to interpret. In order to ease learning over the temporal dimension, we introduce a novel task formulation that harnesses the natural segmentation of ECG signals into heartbeats to drastically reduce the number of time steps per sequence. Additionally, we extend our RNNs with an attention mechanism that enables us to reason about which heartbeats our RNNs focus on to make their decisions. Through the use of attention, our model maintains a high degree of interpretability, while also achieving state-of-the-art classification performance with an average F1 score of 0.79 on an unseen test set (n=3,658).