The second part of the article discusses the spirometry interpretation using the latest international and national recommendations. Different systems of predicted values were considered, attention was paid to the GLI‑2012 reference equations advantages and the z-score assessment. The severity classification, obstructive disorders, extrathoracic and intrathoracic airway obstruction and possible spirometry indications of restrictive and mixed ventilation disorders were considered. The algorithm for spirometry evaluation was also presented, and the most common errors in the spirometry interpretation were discussed. 

Electrocardiography (ECG) is considered as an essential step in acute coronary syndrome (ACS) diagnostic algorithm. Сurrent classification is based on the ECG changes of ST-segment and includes ACS with persistent ST elevation and without persistent ST elevation. ACS with persistent ST elevation is characterized by prolonged (more than 20 min) ST-segment elevation exceeding 0.1 mV in two or more contiguous ECG leads (except V2–3 as well as aVR). When the symptoms of acute myocardial ischemia are present, ECG should be recorded within 10 minutes from the first contact with a medical professional. Some changes on the initial ECG of a patient with ACS may be nonspecific or absent, so the key role in diagnosis is given to the clinical presentation and the ECG in dynamics. 

Cardiac contractility modulation (CCM) is a method of non-drug treatment of chronic heart failure (CHF) in patients with no indications for resynchronization therapy. Now, a detailed study of this method and its capabilities is ongoing, and the indications for its use are expanding. As with any other implantable device, it is important to be able to monitor the operation of the CCM, identify its dysfunction and promptly refer patients to specialized institutions. Assessment of the function of CCM- therapy can be carrying out by recording a standard 12‑channel electrocardiogram (ECG), as well as 24‑hour Holter ECG monitoring (HM-ECG). The mechanism of action of CCM-therapy is fundamentally different from that of other implantable devices. Knowledge of the features of the manifestation of CCM-therapy during instrumental studies is necessary for their correct interpretation. 

Systolic and diastolic BP values are determined guided by measurement signals (Korotkoff tones, oscillations). The source of these signals are hydrodynamic processes occurring in the artery under the influence of cuff pressure on the upper arm. The article is devoted to the study of these processes. The value of body tissues pressure on the artery walls is equal to the value of air pressure in the cuff only at the middle of the cuff and smoothly decreases to zero to its edges. Such non-uniformity of distribution of body tissues pressure on the artery walls is caused by the physical property of elasticity of their shape, which was not taken into account earlier. Therefore, the equality of the value of blood pressure on the artery walls from its inner side and the value of body tissues pressure on the artery walls from its outer side is possible only at one point. At this point, the open part of the artery passes into its constricted part, and the point itself is called the boundary of arterial constriction. The pulsations of blood pressure in the artery caused by the heart cause rhythmic movements of this boundary along the artery. Therefore, the arterial walls open up when the constriction boundary is moved in the distal direction. When the convergence boundary is moved in the proximal direction, the walls of the artery connect. During systole, when the blood pressure exceeds the air pressure in the cuff, the boundary of compression moves distally across the middle of the cuff. At the same time, a blood flow front is formed beyond the middle of the cuff, moving towards the distal edge of the cuff. When this edge is reached, the artery opens across the entire width of the cuff. In the diastole periods following systole, the blood pressure decreases. As a result, the blood pressure drops below the air pressure in the cuff, and the arterial wall at the midpoint of the cuff interconnect again. In this case, there is a re-boundary of constriction moving in the proximal direction. Thus, the hydrodynamics of blood in the artery is completely determined by the movements of the boundary of its compression. This hydrodynamics is substantiated theoretically and confirmed experimentally. It is shown that oscillations of air pressure in the cuff, Korotkoff tones and surface pulse waves are different consequences of a single biomechanical process, which allows us to consider in detail the formation of oscillations, surface pulse waves, as well as to put forward a physically justified version of the Korotkoff tones. 

Yoga breathing exercises that develop the ability to voluntarily regulate the minute volume of respiration (MV) and maintain the state of hypoventilation, hypoxia and hypercapnia, can be considered as a way of hypoxic-hypercapnic training, potentially capable of influencing cerebral circulation and neuroprotective factors. However, at the moment, individual anthropometric features that affect the ability to develop a hypoventilation mode of breathing have not been studied, and methodological criteria for training have not been developed.

Methods: The study involved 44 people (32 men and 12 women) who regularly practice yoga breathing techniques with a voluntary decrease in respiratory rate using maximum tidal volume (TV). Free breathing was recorded for 2 minutes, then each subject performed the respiratory hypoventilation pattern available to him or her (minimum RR values with maximum TV, inhalation and exhalation were of equal duration). The following parameters of external respiration were determined: respiratory rate (RR), minute ventilation (MV), tidal volume (TV), partial pressure of CO2 in the exhaled air at the end of exhalation (PetCO2 ), percentage of O2 in the exhaled air (FeO2) and hemoglobin saturation (SpO2 ).

Results: Compared to breathing at rest (MV = M±SD 8.51 ± 2.57 (95% CI 7.72–9.29) l/min; PetCO2 = M±SD 36.98 ± 3.71 (95% CI 35.85–38.11) mm Hg), the mode with RR = 3 times/min (inspiration and expiration for 10 s), n = 44, leads to an increase in MV up to M±SD 12.02 ± 3.42 (95% CI 10.98–13.06) l/min (p < 0.001) and a decrease of CO2 : PetCO2 = M±SD 33.99 ± 3.59 (95% CI 32.90–35.08) mm Hg (p < 0.001) — that is, to development of alveolar hypocapnia. The mode with RR = 1.5 times/min (inhalation and exhalation for 20 s), n = 44, demonstrates a decrease in MV to M±SD 5.95 ± 1.59 (95% CI 5.46–6.43) l/min (p < 0.001) and growth of PetCO2 up to M±SD 41.19 ± 3.71 (95% CI 40.06–42.32) mm Hg (p < 0.001). The mode with RR = 1 time/min (inspiration and exhalation for 30 s), n = 24: with a decrease in RR to 1 time/min, a decrease in MV was observed to M±SD 4.22 ± 0.92 (95% CI 3.83–4.61) l / min (p < 0.001) and an increase in PetCO2 up to M±SD 44.05 ± 3.05 (95% CI 42.76–45.33) mm Hg (p < 0.001). The breathing pattern with RR = 1 r/min is accompanied by a statistically significant decrease in MV compared to rest, as well as an increase in PetCO2 and a decrease in FeO2 , that is, it is hypoventilation. We have proposed a ventilation coefficient (Qvent), which is the ratio MV/VC, which allows us to judge at what values of MV an individual reaches a state of hypoventilation. It was previously shown in this sample that the breathing exercise becomes hypoventilation when Qvent values are equal to or less than 1. With Qvent in the range from 1 to 2, the ventilation mode is within normal values, and when Qvent is more than 2, hyperventilation occurs.

Conclusion: when performing yoga breathing exercises, variations in MV are observed both in the direction of hyperventilation and in the direction of hypoventilation with corresponding shifts in gas exchange (hypocapnia with hyperventilation, hypercapnia with hypoventilation). The MV values at which an individual reaches hypoventilation vary from person to person and can be predicted using the ventilation coefficient (Qvent).

It is assumed that the wall shear stress (WSS), which determines the function of the endothelium, is constant along the arterial bed. The assessment of turbulence, blood flow velocity in the arterial system in healthy (13 patients) and in patients with the initial form of atherosclerosis in the femoral artery (42 patients) was discussed. The study quantified blood flow in the common femoral artery using V Flow with visualization of blood flow with a high frame rate. The results obtained in the femoral arteries were evaluated by the wall shear rate, velocity profile and oscillation index (OSI). It was shown that the average value of WSSmean in the femoral artery in healthy and in patients with stenosis <30–35% is 0.9± 0.4 – 0.91±0.4 Pa and does not significantly differ. The wall thickness in the common femoral artery in patients with the initial form of atherosclerosis was 0.9–1.1 mm, and in healthy patients 0.8–0.9 mm. The correlation between the parameters was evaluated by nonparametric analysis of Kendall’s Taub. It was revealed that there is no correlation between WSSmean and blood flow velocity (Vs) in both healthy and patients with the initial form of atherosclerosis.

Objective. Study and comparison of the diagnostic performance of various ultrasound elastometry methods in detecting liver fibrosis in patients with heart failure.

Materials and methods. The study was conducted from June 2022 to January 2024. 57 patients with heart failure and metabolic syndrome were examined, divided into three groups depending on the stage of the disease: stage I (n = 21), stage II (n = 24), stage III (n = 11), each of which was divided into subgroups depending on the severity of liver fibrosis (F0–F4). Standard parameters of sensitivity, specificity, and accuracy were used to compare the performance of transient elastometry, vibration-controlled transient elastometry, point elastometry, and two-dimensional shear wave elastometry. A complex of multislice computed tomography with color assessment of the liver structure, a biochemical blood test with the de Ritis coefficient and the FIB‑4 scale were used as a reference method.

Results. In stage I heart failure, all four methods showed similar sensitivity, specificity and accuracy. At stage II, using transient elastometry, sensitivity was 59.4%, specificity — 68.2%, accuracy — 62.4%; visual transient elastometry — 72.8%, 87.2%, 79.4%, respectively; point elastometry — 68.6%, 83.7%, 77.4%, respectively; two-dimensional shear wave elastometry — 89.6%, 94.3%, 91.6%. At stage III, transient elastometry turned out to be uninformative; visual transient elastometry showed a sensitivity of 61.2%, specificity of 70.4%, accuracy of 64.6%; point elastometry — 48.6%, 60.1%, 52.3%, respectively; while two-dimensional shear wave elastometry showed a sensitivity of 85.6%, specificity of 92.5%, accuracy of 88.8%.

Conclusions. For patients with stage I heart failure, the choice of a specific elastometry method is not of fundamental importance, since the indicators do not differ. However, in stages II and III, shear wave elastometry is the preferred method, especially in stage III, where it demonstrates higher diagnostic performance compared to point elastometry. Visual transient elastometry can be used additionally with the method of two-dimensional shear wave elastometry or in the case where two-dimensional shear wave elastometry is not possible. 

Patients with severe brain damage often develop pressure ulcers (PU). The phases of the wound process significantly extend in time due to the underlying disease, severity of the condition and metabolic changes. Medical thermal imaging can be used to assess the level of PU microcirculation.

Aims: to study the possibility of using medical thermal imaging to predict the course of PU in patients after severe brain damage.

Methods: 38 ICU patients after brain injury and stage III–IV PU (25 men, 13 women, mean age 59±17 years). The series of thermograms (native image, after the “cold test” and 3 minutes after) were recorded before treatment and after 21 days. We used an NEC ThermoTracer TH 9100 thermal imager.

Results. We assessed the minimum/maximum overall temperatures and in the 1st–4th quartiles. With a positive outcome, the temperatures Q3-Q4 were higher (35.1 C–37.6 C versus 34.8 C–36.7 C for a negative outcome) and the lower thresholds of all quartiles. We hypothesized that a sign of PU healing is a narrowing of the range of temperature points on the surface of the wound. We used a point system for assessing the dynamics of temperature parameters, then checked the model using ROC analysis: the AUC was 0.932 (0.81–1.0), which indicates the high quality. The best ratio of sensitivity and specificity (0.81; 0.83) corresponds to a cut-off point of 9.5.

Conclusion. The use of medical thermal imaging makes it possible to objectively assess the level of blood supply to the PU in patients after severe brain damage, as well as the prognosis of further wound healing.