Ultra-High-Frequency Electrocardiography

Background: We introduce a new technology that uses the ultra-high-frequency components (150–1000 Hz) of the electrocardiogram (UHF-ECG). Method: The UHF-ECG components represent weak signals generated by the depolarization of myocardial cells. The amplitude of UHF oscillations decreases with distance from the source. This property and the different timing of depolarization in the ventricles' volume enable mapping of the ventricular activation from the chest ECG leads. Because of a low signal-to-noise ratio of UHF oscillations, averaging must be performed. Single recording thus lasts 30 seconds and more. Results: UHF-ECG defines the time-spatial distribution of myocardial electrical activity. Corresponding numerical parameters are electrical dyssynchrony (e-DYS) and the duration of local depolarization (Vd). UHF ventricular depolarization maps present details of electrical activation. Conclusion: The UHF-ECG uses a new source of information originating in ventricular volumes that is different from the standard ECG. It provides information about the volumetric electrical activation associated with mechanical contraction. Its primary clinical utilization is in cardiac resynchronization, pacing optimization, and conduction system pacing.