PSI - Issue 40

V. Mironov et al. / Procedia Structural Integrity 40 (2022) 296–306

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V. Mironov at al. / Structural Integrity Procedia 00 (2022) 000 – 000

fragments by means of a graphic cursor and a special program. This stabilization fragment correlated to the duration of clinical and ECG symptoms of ischemic episodes. This is the evidence of stenocardia in pts and it could be analyzed on the frequency, duration of ischemia, the hemodynamic importance, on the functional class of the angina pectoris initially before operation, on arrhythmogenic background of the autonomic sinoatrial node deregulation (Patents No. 2068650, 2322942). 30 minutes before CABGS, premedication by diazepam, seduces or relium, atropine, promedole, and other drugs and intubation narcosis were applied. There was a suppression of the fast-autonomic regulation and increase in the humoral-metabolic influence and spectral share in SN during surgery in all subjects (Table 3; Fig. 3). Correspondingly, HRV autonomic indices, namely σm, σs, SDNN , and their spectral shares (LF%, HF%), decreased too and humoral-metabolic spectral shares VLF% increased. In the spectral shares, there were humoral influences in the form of an increase in spectral density in a very low-frequency diapason of HRV (Fig. 3). Such HRV stabilization was in all pts during all the stages of CABGS after premedication and during narcosis (Table 3), at the vessel clipping, introduction of the cardioplegic solutions, connection to the apparatus of artificial circulation, removing clips from aorta and vessels, etc. till the starting of heart contractions by themselves (Table 3). Most of cardioarhythmias were registered during the heart starting after operation (Figs. 4 and 5). The most severely ill patients had the lowest HRV indices with the syndrome of ACN. There were 56 pts of the kind. HRV of these pts being compared with HRV of other 67 pts, the lowest wave structure amplitude was in pts with ACN (Table 2). In Fig. 2, RCGs of a pt who died after CABGS is presented. He had an extremely pronounced stabilization of the rhythm on the background of tachycardia and replacement rhythms. Thus, ACN before operation is a predictor of complications and a lethal outcome. The RCG studying is very important before a cardiology operation and other surgeries. The HRV registration before myocardium revascularization with cardiac arrest is expedient for the purpose of identification of the risk of complications during shunting and registration of the complications from the intraoperative cardiac arrhythmias, because their occurrence was related to a previous arrhythmogenic background. This background was the following: dysfunctions of the sinoatrial heart node, extremely expressed decrease of all HRV waves (SDNN, σm, σs ) because of the loss of autonomic control in the form of ACN before CABGS, initial episodes of the ischemic autonomic denervation, ECG changes of sinoatrial blockade of 2 or 3 degrees. Before CABGS, HRV studying in rest and 4 directed tests were made. After the premedication and narcosis, RCG was registered without the assessment of autonomic indices. After premedication and intubation anesthesia, HRV-wave structure was absent on the RCG, otherwise, the preservation of any HRV-fluctuations could be considered as insufficient fitness for surgery. The autonomic HRV indices had decreased amplitudes in units of seconds and at all position (Tables 2 and 3; Fig. 3) and arrhythmias in the absence of autonomic control. The majority of cardiac arrhythmias were registered during surgeon manipulations, namely the installation of clips in vessels and aorta (Figs. 4 and 5), connection to artificial circulation, and the removal of clips from vessels, sometimes by starting with a direct heart massage. All these actions were accompanied by heart arrhythmias. 4. Conclusions High-resolution rhythmocardiography with statistical and spectral analyses of heart rate variability is an informative, adequate, modern, and perspective method of formalized diagnostics of the heart deregulations and actual status of the cardiovascular system before, after, and during myocardial revascularization by the coronary artery bypass graft surgery, and for the prevention and treatment of complications before, during, and after myocardium revascularization in patients with coronary artery disease and angina pectoris. High-resolution RCG data before and after myocardial revascularization procedure revealed the decline of patient’s status during the early post -surgery period presented as all the wave structure amplitudes of the heart rate variability decrease. The syndrome of the autonomic cardioneuropathy is a predictor of complications during and after CABGS and it is presented by the heart rate variability stabilization and the loss of heart rhythm fast-autonomic control. Heart arrhythmias and asystole during surgery can occur due to the surgeon ’s manual pulsations, for example, during the introduction and removing of the clips from vessels, heart massage, and others.