Fusion-Based Deep Learning Ensemble on MIT-BIH and PTB-XL ECG Databases for Enhanced Cardiac Diagnosis

Electrocardiogram (ECG) analysis plays a critical role in the early detection and diagnosis of cardiac abnormalities. In this study, we propose a fusion-based deep learning ensemble framework that integrates two well-established public ECG databases, MIT-BIH Arrhythmia Database and PTB-XL, to develop a robust and automated cardiac diagnostic system. Our framework employs two base deep learning models — a CNN+LSTM hybrid and a DenseNet1D-inspired network — and combines their predictive features through a meta-learner based on Gradient Boosting. This multi-model integration, designed as a “mini doctor for the heart,” leverages the complementary strengths of both datasets and models. Experimental results demonstrate that the ensemble achieves near-perfect performance with Accuracy up to 100% and ROC-AUC of 1.000, surpassing the performance of individual models. These findings highlight the potential of database fusion and model ensembling for building reliable and scalable solutions in computer-aided cardiac diagnosis.Preprint originally posted on medRxiv:https://doi.org/10.1101/2025.08.20.25334079