PSI - Issue 40

V.A. Mironov et al. / Procedia Structural Integrity 40 (2022) 307–313 V. A. Mironov at al. / Structural Integrity Procedia 00 (2022) 000 – 000

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autonomic system there are 2 parts of regulation with various mediators. In healthy people their actions are opposed to each other. Consequently, another thing that suffers in IHD patients is the sinoatrial node, namely its pacemaker cells. The disappearance of the heart rate wave structure modulated by the varying tonus of the two parts of the autonomic system is fraught with the activation of arrhythmogenic centers amid rhythm stabilization (Figs. 2 and 3). Heart rhythm stabilization corresponding to the CAN syndrome, which is most often found in patients with EA of FCs 3 and 4, is shown in Fig. 2. Figure 3 demonstrates the transition of CAN into substitute rhythms of atrial fibrillation with a risk of transformation into atrial tachycardia. Electron microscopy of autopsy material was performed. Figure 4 demonstrates the normal structure of a sinus node pacemaker cell. The dystrophy of such a cell is shown in Fig. 5. It is polyetiological, in the presented material the dystrophy resulted from chronic dysfunction of blood supply to the SAN during severe IHD. With established dystrophy, pacemaker cells are unable to respond to rapid ANS regulation and to provide normal impulse transmission into the cardiac conduction system. Cardiac autonomic neuropathy revealed by RCG before PCAP operation predicts a high risk of unsuccessful surgery. Dystrophic disorders of atherosclerotic etiology can hardly be local due to the systemic character of vessel damage. Therefore, the PCAP operation must be performed as early as possible, and RCG is fairly informative in this case.

Fig. 2. The rhythmocardiogram, spectrogram, and average HRV parameters for a patient with cardiac autonomic neuropathy (CAN). RCG has no waves. Judging by the spectra, the SAN is regulated under the influence of the humoral metabolic environment, insufficiently effective and slow.