Synthesizing surface ECGs from intracardiac electrograms using an adaptive filter method

This study investigates the feasibility of synthesizing surface ECG (SECG) from the intracardiac electrogram (IEGM) measured by the implanted device. Using an adaptive filter approach, we characterize the optimal filters relating the representative IEGM templates and the desired SECG templates. The optimal filters, which vary from sample to sample and are specific to event types, are then used to process the IEGM input to generate the pseudo-ECG output. The algorithm was preliminarily evaluated on experimental data collected from an anaesthetized pig and in selected data from the Ann Arbor Electrogram Libraries. In all tested cases, the morphological features of the pseudo-ECG are highly comparable to the SECG, and clinically relevant cardiac rhythm information was preserved. The IEGM derived pseudo-ECG may provide useful diagnostic information and facilitate implant device follow-up.