An electrocardiography monitor configured for self-optimizing ECG data compression is provided. ECG waveform characteristics are rarely identical in patients with cardiac disease making this innovation crucial for the long-term data storage and analysis of complex cardiac rhythm disorders. The monitor includes a memory and a micro-controller operable to execute under a micro-programmable control and configured to: obtain a series of electrode voltage values； select one or more of a plurality of compression algorithms for compressing the electrode voltage series； apply one or more of the selected compression algorithms to the electrode voltage series； evaluate a degree of compression of the electrode voltage series achieved using the application of the selected algorithms； apply one or more of the compression algorithms to the compressed electrode voltage series upon the degree of compression not meeting a predefined threshold； and store the compressed electrode voltage series within the memory.
