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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1. Introduction During surgery or intervention, the status of the cardiovascular system (CVS) is of primary importance since abnormalities may become life-threatening due to the extreme nature of surgery in most cases. Cardiovascular complications during surgery and in the postoperative period require thorough supervision of the current CVS state. Since any CVS disorders begin with heart rhythm dysregulation, high-precision heart rate variability (HRV) analysis can prove to be a method enabling one to reveal predictors of fatal events and therefore acceptable in surgery since, with high-resolution firmware, it reflects the slightest abnormalities and their dynamics. Approbation of high resolution rhythmocardiography (RCG) in surgery is urgent. Its usefulness has been proved for studying HRV regulation in patients with stable effort angina (EA) before and after heart bypass surgery during myocardial revascularization. The differences in the interpretation of the results of HRV analysis in patients with EA (National recommendations 2011), Mironova at al. (2000, 2008), Vein at al. (2003) are attributed to the incomplete assessment of autonomic changes alone, without taking into account the effect of the extracellular environment on the velocity of ion currents through the membrane of the pacemaker (PM) cells of the sinoatrial node (SAN). However, the proven classical physiology implies the effect of the humoral metabolic extracellular environment on ion current velocity and on the potential of the action of the pacemaker cells of the SAN, the main cardiac pacemaker. Yet, they are dependent on the composition of the extracellular environment, which is a substrate of the discharge of all metabolic processes, mediators and endocrine products. Normally, this environment, together with rapid sympathetic and parasympathetic autonomic regulation, governs the SAN activity. The Framingham study investigated autonomic heart rate regulation with taking into account humoral and metabolic factors (1994).

Nomenclature CVS

central venous pressure

HRV heart rate variability SAN sinoatrial node ECG electrocardiography RCG PCAP percutaneous angioplasty CAG coronary angiography AF atrial flutter

high-resolution rhythmocardiography

2. Materials and Methods 28 patients with EA of functional classes (FC) 3 and 4 without somatic comorbidity were selectively studied by standard cardiological methods and coronary angiography (CAG) since they had been sent to undergo percutaneous angioplasty (PCAP). For testing by standard methods, 41 healthy men aged similarly to the patients were checked without CAG. Both groups also underwent high-resolution RCG with HRV analysis under identical conditions. RCG immediately preceded PCAP. This paper presents the results of RCG before surgical intervention in 28 patients with cardiac angina of FCs 3 and 4. The indications for surgery were ineffectiveness of conservative therapy, persistent symptoms, and verified coronary nature of the pain syndrome. Besides standard cardiac checkup immediately before PCAP, RCG was performed a day before the surgery, early in the morning, before medications, since at high PM discretization they would have affected the initial RCG results. Before the surgery, rhythmocardiograms with 5-minute episodes in 6 positions were recorded for all the 28 EA patients. HRV data for 41 healthy people comparable with the main group of EA patients in age and sex were used as the control.