Study of the Ventricular Late Potentials Characteristics of the Patients with Heart Conducting Ways Abnormality

The detection and analysis of late ventricular potentials (VLP) are discussed using synchronous recordings of 12-channel surface ECG signals and intracardiac electrograms. A verified database of ECG signals and intracardiac electrograms with a sampling frequency of 1 kHz and a resolution of 24 bits was formed. VLP signal detection is based on studying the vector magnitude (VM) signal in the range from QRSoff to J-point. The VM signal is formed by a synchronous accumulation of 12-channel ECG signals for 10 cardio cycles and linear conversion into orthogonal ECG signals. A particular signal was developed to detect the ECG signal characteristic points reliably. This signal was preprocessed using band-pass filtering of the first lead signal in the range from 0.1 Hz to 25 Hz, on which the QRSon, QRSoff, and J-point points were identified. Those points were used to evaluate the characteristics of the VLP signal. The intracardiac electrograms were used to verify the abnormalities of the heart conduction pathways and determine their localization and areas. It is shown that the shape and characteristics of the late potentials depend on the area size and the disturbance degree. The ratio of the orthogonal ECG signals orientation characteristics of the electric heart vector to the VLP signal section can be used to localize the area with impaired conduction pathways. VLP signals and intracardiac electrograms of patients with various pathway disorders are discussed.