A simple theoretical model accurately predicted in vivo human unipolar electrogram morphology, showing high similarity between recorded and simulated UEGs (median cc 0.89; IQR 0.72-0.95).
Observational (n=18)
In vivo human epicardial mapping data validates a simple theoretical model of unipolar electrogram morphology, providing a framework for understanding UEGs.
Effect estimate: Median cc 0.89 (95% CI 0.72-0.95)
Abstract Introduction The unipolar electrogram (UEG) provides local measures of cardiac activation and repolarization and is an important translational link between patient and laboratory. A simple theoretical model of the UEG was previously proposed and tested in silico . Method and results The aim of this study was to use epicardial sock‐mapping data to validate the simple model's predictions of unipolar electrogram morphology in the in vivo human heart. The simple model conceptualizes the UEG as the difference between a local cardiac action potential and a position‐independent component representing remote activity, which is defined as the average of all action potentials. UEGs were recorded in 18 patients using a multielectrode sock containing 240 electrodes and activation (AT) and repolarization time (RT) were measured using standard definitions. For each cardiac site, a simulated local action potential was generated by adjusting a stylized action potential to fit AT and RT measured in vivo . The correlation coefficient (cc) measuring the morphological similarity between 13,637 recorded and simulated UEGs was cc = 0.89 (0.72–0.95), median (Q 1 –Q 3 ), for the entire UEG, cc = 0.90 (0.76–0.95) for QRS complexes, and cc = 0.83 (0.58–0.92) for T‐waves. QRS and T‐wave areas from recorded and simulated UEGs showed cc> 0.89 and cc> 0.84, respectively, indicating good agreement between voltage isochrones maps. Simulated UEGs accurately reproduced the interaction between AT and QRS morphology and between RT and T‐wave morphology observed in vivo . Conclusions Human in vivo whole heart data support the validity of the simple model, which provides a framework for improving the understanding of the UEG and its clinical utility.
Orini et al. (Mon,) conducted a observational in Cardiac electrophysiology (n=18). Simulated local action potential model vs. In vivo recorded unipolar electrograms was evaluated on Morphological similarity between recorded and simulated unipolar electrograms (Median cc 0.89, 95% CI 0.72-0.95). A simple theoretical model accurately predicted in vivo human unipolar electrogram morphology, showing high similarity between recorded and simulated UEGs (median cc 0.89; IQR 0.72-0.95).