Trigeminy electrocardiogram spectral characteristics study

This paper presents the results of a study in which the method of ECG decomposition in the time domain (DMTD) was applied, followed by a spectral analysis. A digital signal with trigeminy of the first lead of a standard electrocardiograph was processed. Using digital filtering in time domain, the electrocardiogram (ECG) was cleared of noise, what results the reduction of spurious components by 10-20%. To represent and classify the frequency characteristics throughout the entire processed cardiac signal, the QRS complexes were removed, P and T waves were left unchanged. Due to considerable influence on the spectral analysis sharp peaks of the ECG signal with small characteristic times of the leading and trailing edges, the obtained result differs considerably from the sum of the harmonic components of the smooth part of the signal. The spectral processing reveals peaks at multiple frequencies, 1.6 Hz, 3.2 Hz, 4.7 Hz, corresponding to a smooth function of P and T waves before the appearance of extra systoles. Based on the obtained data, the frequencies corresponding to the peaks of the cardiogram with a stable sinus rhythm were identified. The acquired data represent regular harmonics, which allow adequate quantitative ECG analysis.