The Use of Ketamine as Therapy for Depression

Depressive disorder is still a significant problem in several developed countriesand is morbidity caused by mental disorders. With the development of science,now discovered the unique pharmacodynamic properties of ketamine, which isused as an antidepressant. As we know in clinical practice, ketamine is used foranaesthesia, analgesia, sedation, and chronic pain management. Rapid-onsetantidepressants resulted from increased levels of BDNF in the hippocampus.Extracellular glutamate agents are not new for the treatment of depression.According to the neurobiology view, depression is a monoaminergic phenomenon,so this is the impetus for discovering a new generation of antidepressants.Ketamine can be given intravenously in subanesthetic doses. Still, monitoringmust be carrying in therapy administration because of the possible side effectssuch as hypersalivation, tachycardia, increased systemic arterial pressure, andintracranial pressure.

PSYCHOPHYSIOLOGICAL ASSESSMENT OF THE LABOR OF MEDICAL WORKERS IN ORGANIZATIONS WITH COVID-19

Introduction. High neuro-emotional stress among medical workers in organizations with the leading harmfulness of Covid-19 contributes to the formation of an unfavorable functional state, increases the risks of health disorders. The study of the characteristics of the psychophysiological reactions of the body will allow to substantiate the timing of work in a pandemic, which is quite relevant at the present time. The purpose of the research was, on the basis of comprehensive psychophysiological studies, to study the features of the formation of a functional state in medical personnel working in organizations with COVID-19 under the influence of stress factors of the labor process. Materials and methods. A physiological and hygienic assessment of the intensity of the labor process was carried out, psychophysiological changes were studied during 3 months of work in the «dangerous» zone. Statistical processing of the obtained data was carried out using the statistical programs Statistika 10, Microsoft Excel 2010. Results. The formation of neuropsychic stress in medical workers is reflected in changes in ECG indicators (prolongation of the QT interval, decrease in the voltage of the P and T waves) and systemic arterial pressure, an increase in the endurance coefficient (an indicator of detraining of the cardiovascular system), positive values of the Kerdo autonomic index (predominance of sympathetic influences) after 3 months of work in medical organizations with Covid-19. Conclusions. Nervous and emotional tension at work is the leading professional factor among nurses and doctors working in medical institutions with Covid-19 (hazard class 3, grade 3). Indicators of the cardiovascular system, reflecting the degree of adaptation of the body of medical workers to production activities, can be used to justify different periods of work in organizations with Covid-19.

The Use of Ketamine as Therapy for Depression

Depressive disorder is still a significant problem in several developed countries and is morbidity caused by mental disorders. With the development of science, now discovered the unique pharmacodynamic properties of ketamine, which is used as an antidepressant. As we know in clinical practice, ketamine is used for anaesthesia, analgesia, sedation, and chronic pain management. Rapid-onset antidepressants resulted from increased levels of BDNF in the hippocampus. Extracellular glutamate agents are not new for the treatment of depression. According to the neurobiology view, depression is a monoaminergic phenomenon, so this is the impetus for discovering a new generation of antidepressants. Ketamine can be given intravenously in subanesthetic doses. Still, monitoring must be carrying in therapy administration because of the possible side effects such as hypersalivation, tachycardia, increased systemic arterial pressure, and intracranial pressure.

Postsystolic thickening is a potential new clinical sign of injured myocardium in marfan syndrome

The mechanisms leading to cardiac remodeling in Marfan syndrome (MFS) are a matter of debate since it could be either due to structural dysfunction of the myocardial extracellular matrix or to increased afterload caused by the dilated aorta. We aim to characterize the presence of abnormal myocardial function in MFS and to investigate its potential association with increased afterload. Aorta, left ventricle (LV) and the postsystolic thickening (PST) were analyzed in echocardiography in Fbn1C1039G/+ mice and in patients with MFS in comparison with wild type (WT) mice and healthy humans. PST was more frequent in MFS than in WT mice (p < 0.05). MFS mice with PST showed larger aorta than those without PST. Patients with MFS showed larger aorta, poorer LV function and a higher prevalence of PST (56%) than did the healthy controls (23%); p = 0.003. Blood pressure was similar. The higher prevalence of PST in an experimental murine model and in MFS patients, regardless of systemic arterial pressure, suggests an increased afterload on the LV myocardium. This finding supports the use of PST as an indicator of myocardial damage and encourage searching for novel early preventive therapy.

The Effect of Mesenchymal Stem Cells Transplantation on Cardiac Functioning and Contractility in Experimental Myocardial Infarction

Introduction. Heart failure as a result of ischemic myocardial remodeling is one of the most severe diseases with poor prognosis. Drug therapy alone with surgical or percutaneous revascularization of damaged myocardium often fails to achieve optimum effect in the treatment of the mentioned syndrome. Cell cardiomyoplasty using autologous bone marrow derived mesenchymal stem cells (BM-MSCs) has already proved to be promising alternative to both these treatment methods, as it’s aimed directly at restoration of normally functioning myocard. The aim. To study the effects of different techniques of cardiomyoplasty with BM-MSCs on morphometrical and functional indices of post-infarctional left ventricular remodeling in experiment. Materials and methods. An experimental model of myocardial infarction in laboratory rats was used for the research. The survived animals were equally divided into 5 groups; the animals of 3 groups underwent BM-MSC transplantation. A certain technique of cardiomyoplasty was used in each of the 3 groups: direct injection into necrotic myocardium, intravenous injection and injection inside left ventricular cavity (which imitates intracoronalintroduction). Other 2 groups were comparison groups where the animals did not achieve BM-MSCs after infarction. There was also control group with intact animals with normal values of all the studied indices. The following invasive and noninvasive measurements of functional heart indices have been done in all research groups: left ventricular weight and its relation to body weight, end-systolic and end-diastolic left ventricular internal dimensions, fractional shortening, ejection fraction, stroke volume, heart rate, systemic arterial pressure and left ventricular inner pressure, both systolic and diastolic. The follow-up period was 1 and 3 months after the experiment. Finally, all animals were euthanized and autopsied, and the results of macroscopic examination of their hearts have been matched with aforecited functional indices in each group. Results and discussion. The analysis of all measured parameters and their comparison between groups have revealed that BM-MSC transplantation (irrespective of technique) conduces to reliably significant retention of functioning myocardium volume, reliably significant improvement of contractility parameters, particularly, reduced end-systolic and end-diastolic internal dimensions, increased ejection fraction, fractional shortening and stroke volume; it also contributes to maximal inalterability of such hemodynamic parameters as heart rate, systemic arterial pressure, left ventricular inner pressure. In addition, in all 3 groups of cell therapy the indices of contractility and pump function of the left ventricle were very close to normal rates. But the optimal results have been obtained in the group of direct intramyocardial injections. Conclusion. Cell cardiomyoplasty with BM-MSCs tends to prevent ischemic myocardial remodeling and, as a result, to improve myocardial contractility and neutralize manifestations of severe heart failure in short-term follow-up of 1 and 3 months.

Impact of Systemic Arterial Pressure, Collateral Vascular Resistance and Degree of Carotid Stenosis on Cerebral Blood Flow, Reserve Blood Flow, Critical Carotid Stenosis, Cerebral Ischemia and Carotid Hemodynamics

IntroductionCarotid artery stenosis related stroke is a major health care concern. Current risk management strategies for patients with asymptomatic carotid stenosis include ultrasound surveillance and occasionally an estimate of cerebral blood flow reserve. Other patient specific hemodynamic variables may be predictive of ischemic stroke risk. This study, based on a cerebral blood flow hemodynamic model, aims to investigate the impact of systemic arterial pressure, collateral vascular resistance and degree of carotid stenosis on cerebral ischemic risk, cerebrovascular blood flow reserve, critical carotid artery stenosis, carotid artery blood flow and carotid stenosis hemodynamics.MethodsThis study uses a three-component (carotid, collateral, brain) energy conservation cerebrovascular fluid mechanics model in combination with the Lassen cerebral blood flow autoregulation model that predicts cerebral blood flow in patients with carotid stenosis. It is a two-phase model, zone A when regional cerebral blood flow is autoregulated at normal values and zone B when cerebral blood flow is below normal and dependent on collateral perfusion pressure. The model solution with carotid artery occlusion defines collateral vascular resistance, with patient specific values calculated from clinical pressure measurements. In addition to cerebral blood flow the model predicts critical stenosis values and carotid and collateral blood flows as a function of systemic arterial pressure and percent diameter stenosis. Carotid stenosis blood flow velocities and energy dissipation are predicted from carotid blood flow solutions.ResultsThe model defines patient specific collateral vascular resistance, cerebral vascular resistance and critical carotid stenosis. It predicts carotid vascular resistance to be non-linearly proportional to area carotid stenosis. Solutions include reserve cerebral blood flow, the carotid and collateral components of cerebral blood flow, criteria for cerebral ischemia and carotid stenosis hemodynamics. Critical carotid stenosis is determined by mean systemic arterial pressure and the Lassen autoregulation threshold cerebral perfusion pressure. Critical stenosis values range from 61% to 76% diameter stenosis when mean systemic arterial pressures are 80mmHg to 120mmHg and the cerebral autoregulation pressure threshold is 50mmHg. When carotid stenosis is less than critical, cerebral blood flow is maintained normal and the ratios of carotid blood flow to collateral blood flow are inversely proportional to the carotid to collateral vascular resistance ratios. At stenosis greater than the critical, carotid blood flow is not adequate to maintain normal cerebral blood flow, cerebral blood flow is primarily collateral flow, all reserve blood flow is collateral and prevention of cerebral ischemia requires adequate collateral flow. Patient specific collateral vascular resistance values less than 1.0 predict normal cerebral blood flow at moderate to severe stenosis. Values greater than 1.0 predicts cerebral ischemia to be dependent on the magnitude of collateral vascular resistance. Systemic arterial pressure is a major determinant of carotid stenosis hemodynamics. Carotid blood flow velocities increase with carotid stenosis and have progressively higher variance depending on collateral blood flow as predicted by collateral vascular resistance. Turbulent flow energy dissipation intensity is similarly inversely proportional to collateral vascular resistance at severe carotid stenosis.ConclusionsCerebral, collateral and carotid blood flow solutions are determined by systemic arterial pressure, collateral vascular resistance and degree of stenosis. Critical carotid stenosis, systemic arterial pressure and collateral vascular resistance are primary determinants of cerebral ischemic risk in patients with significant carotid stenosis.

Does left atrial appendage occlusion influence left atrial hemodynamics? Pilot results of invasive intra-cardiac measurements

Introduction Although left atrial appendage (LAA) obliteration is the cornerstone of stroke prevention in surgical treatment of atrial fibrillation (AF), little is known about its direct impact on hemodynamics. In the current pilot study, we evaluated the hemodynamic effect of LAA closure by clipping in patients undergoing hybrid AF ablation. Methods Seven patients with paroxysmal or persistent AF were included. Hemodynamic and intracardiac pressure measurements such as systemic, pulmonary artery (PA), central venous and LA pressure, cardiac output and indexed left ventricular stroke volume (LVSVi) were measured directly before (T0) and after (T1), and 10 minutes after (T2) LAA closure. Results Of the 7 patients (median 66 yrs), 5 were in AF at the time of incision. There were no differences between T0 and T1, T1 and T2 and T0 and T2 for LA pressure, mean PA pressure, LVSVi and other hemodynamic parameters such as central venous oxygenation and pressure, or systemic arterial pressure. Conclusion In this pilot study, the direct hemodynamic effect of LAA closure is evaluated for the first time. Clipping of the LAA is safe and does not directly affect hemodynamic and intracardiac pressures.

Determinants of Cerebrovascular Reserve in Patients with Significant Carotid Stenosis

IntroductionIn patients with 70% to 99% diameter carotid artery stenosis cerebral blood flow reserve may be protective of future ischemic cerebral events. Reserve cerebral blood flow is created by brain auto-regulation. Both cerebral blood flow reserve and cerebrovascular reactivity can be measured non-invasively. However, the factors and variables that determine the availability and magnitude and of reserve blood flow remain poorly understood. The availability of reserve cerebral blood flow is a predictor of stroke risk. The aim of this study is to employ a hemodynamic model to predict the variables and functional relationships that determine cerebral blood flow reserve in patients with significant carotid stenosis.MethodsA basic one-dimensional, three-unit (carotid, collateral and brain) energy conservation fluid mechanics blood flow model is employed. It has two distinct but adjacent blood flow components with normal cerebral blood flow at the interface. In the brain auto-regulated blood flow component cerebral blood flow is maintained normal by reserve flow. In the brain pressure dependent blood flow component cerebral blood flow is below normal because cerebral perfusion pressure is below the lower threshold value for auto-regulation. Patient specific values of collateral vascular resistance are determined from a model solution using clinically measured systemic and carotid arterial stump pressures. Collateral vascular resistance curves illustrate the model solutions for reserve and actual cerebral blood flow as a function of percent diameter carotid artery stenosis and mean systemic arterial pressure. The threshold cerebral perfusion pressure value for auto-regulation is assumed to be 50 mmHg. Normal auto-regulated regional cerebral blood flow is assumed to be 50 ml/min/100g. Cerebral blood flow and reserve blood flow solutions are given for systemic arterial pressures of 80, 90, 100, 110 and 120 mmHg and for three patient specific collateral vascular resistance values, Rw = 1.0 (mean patient value), Rw = 0.5 (lower 1 SD) and Rd = 3.0 (upper 1 SD).ResultsReserve cerebral blood flow is only available when a patients cerebral perfusion pressure is in the normal auto-regulatory range. Both actual and reserve cerebral blood flows are primarily from the carotid circulation when carotid stenosis is less than 60% diameter. Between 60% and 75% stenosis the remaining carotid blood flow reserve is utilized and at higher degrees of stenosis all reserve flow is from the collateral circulation. The primary independent variables that determine actual and reserve cerebral blood flow are mean systemic arterial pressure, degree of carotid stenosis and patient specific collateral vascular resistance. Approximate 16% of patients have collateral vascular resistance greater than 5.0 and are predicted to be at high risk of cerebral ischemia or infarction with progression to severe carotid stenosis or occlusion. The approximate 50% of patients with a collateral vascular resistance less than 1.0 are predicted to have adequate cerebral blood flow with progression to carotid occlusion, and most maintain some reserve. Clinically measured values of cerebral blood flow reserve or cerebrovascular reactivity are predicted to be unreliable without consideration of systemic arterial pressure and degree of carotid stenosis. Reserve cerebral blood flow values measured in patients with only moderate 60% to 70% carotid stenosis are in general too high and variable to be of clinical value, but are most reliable when measured near 80% diameter stenosis and considered as percent of the maximum reserve blood flow. Patient specific measured reserve blood flow values can be inserted into the model to calculate the collateral vascular resistance.ConclusionsPredicting cerebral blood flow reserve in patients with significant carotid stenosis is complex and multifactorial. A simple cerebrovascular model predicts that patient specific collateral vascular resistance is an excellent predictor of reserve cerebral blood flow in patients with significant carotid stenosis. Cerebral blood flow reserve measurements are of limited value without accounting for systemic pressure and actual percent carotid stenosis. Asymptomatic patients with severe carotid artery stenosis and a collateral vascular resistance greater than 1.0 are at increased risk of cerebral ischemia and may benefit from carotid endarterectomy.

Prognostic value of pulmonary-systemic pressure ratio and fibrosis-4 index in patients admitted for acute decompensated heart failure

Background Concomitant presence of pulmonary hypertension in heart failure (HF) is associated with increased adverse events and may be related to interventricular uncoupling and impaired cardiac efficiency. An increased mean pulmonary artery pressure to mean systemic arterial pressure ratio (MPS ratio), a marker of interventricular coupling and efficiency, is reported to be associated with worse clinical outcomes in patients with advanced HF. On the other hand, cardiohepatic interactions have been a focus of attention in HF, and liver dysfunction in HF patients is caused by liver congestion, which is related to liver stiffness. It has been recently shown that liver stiffness assessed by non-invasive fibrosis marker such as Fibrosis-4 (FIB4) index predicts the mortality in HF patients. However, there is no information available on the prognostic value of the combination of MPS ratio and FIB4 index in patients with acute decompensated heart failure (ADHF). Methods and results We studied 238 patients admitted for ADHF, who underwent right heart catheterization at the admission and were discharged with survival. MPS ratio was obtained at the admission. FIB4 index was calculated by the formula: age (yrs) × AST [U/L] / (platelets [103/μL] × √(ALT[U/L])). FIB4 index &gt;2.67 was defined as abnormal, as previously reported. During a follow up period of 5.2±4.4 yrs, 93 patients died. At multivariate Cox analysis, MPS ratio (p=0.01) and FIB4 index (p=0.01) were significantly associated with the total mortality, independently of creatinine level and prior heart failure hospitalization, after the adjustment with hemoglobin, albumin levels and body mass index. The patients with both MPS ratio ≥0.388 (determined by ROC analysis; AUC 0.613 [0.541–0.687]) and abnormal FIB4 index had a significantly increased risk of the total mortality than those with either greater MPS or abnormal FIB4 index and none of them (52% vs 40% vs 28%, p=0.0068, respectively). Conclusion The combination of MPS ratio and FIB4 index might be useful for stratifying ADHF patients at higher risk for the total mortality. Funding Acknowledgement Type of funding source: None