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Biomedical subjects

A A Efremov

Publications and source records attributed to A A Efremov.

8 recordsLinked to original sources
PubMedDate not supplied

[The system of neurohumoral regulation during bypass surgery without extracorporeal blood circulation].

The activity of sympathyco-adrenal, and of serotonin-hystain-cholinergic systems was studied in 34 patients operated for the ischemic heart disease without extracorporeal blood circulation. A moderate increase of parameters characterizing the condition of sympathyco-adrenal, and of serotonin-hystain-cholinergic systems was noted in patients in the perioperative period. The activity of the studied systems reduced due to a total anesthetization. At the same time, the activation of the factors of the neurohumoral system was limited by the adaptation norms with sufficient reserves being preserved.

Acetylcholinesterase↗
PubMedDate not supplied

[Risk factors of atrial fibrillation after aortocoronary bypass surgery with extracorporeal blood circulation].

Fibrillation of the atriums is registered in 20-40% of cases after the surgery of direct revascularization of the myocardium and runs alongside with impairments that are life-menacing. Seventy-six (76) patients were examined after direct revascularization of the myocardium, including 20 subjects with paroxysms of atrium fibrillation. The arrhythmia-related risk was shown to be increasing in persons (older than 60) with an impaired left column of the left coronary artery, in unstable angina pectoris diagnosed before surgery, malfunction of the left ventricle and in case of a rapid warming-up of a patient after the artificial blood circulation with cold cardioplegia is over.

Atrial Fibrillation↗
PubMedDate not supplied

[Cardiac arrhythmias during coronary bypass surgery without extracorporeal circulation].

Ventricular arrhythmias are recorded in most patients at coronary bypass surgery without extracorporeal circulation. The stages, such as the pulling of the sternal edges apart, the opening of the pericardium, the revision and dislocation of the heart, and revascularization of coronary arteries, are most dangerous due to the fact that they may lead to the development of arrhythmias. The major proarrhythmogenic factors at coronary bypass surgery without extracorporeal circulation are mechanical irritation of reflexogenic areas and myocardial ischemia, the mechanical factors playing the leading role in the development of ventricular arrhythmias.

Arrhythmias, Cardiac↗
PubMedDate not supplied

[Parameters of thermoelectric cooling devices in conditions of variable temperatures of the heat-exchange media].

New method for optimized computing thermoelectric coolers is proposed for the case of variable temperatures within heat-transfer media. The operation of the device is analyzed when the temperature of the cooled medium is greater than the temperature of the heated one, i. e. under conditions of the negative temperature difference. The comparative analysis of the computed and experimental data in values of the cooling and electric power demonstrates fully satisfactory results.

Refrigeration↗
PubMedDate not supplied

[Feasibility of constructing thermoelectric thermoregulatory units for artificial circulation devices].

The prospects for the use of thermoelectric systems to regulate the blood temperature in extracorporeal circulation apparatus are outlined. The temperature and electric conditions in the thermoelectric thermoregulating system were optimized, which enabled extremal values of their basic parameters to be obtained. A conclusion is drawn on the expediency of using these systems for the purpose in view.

Blood↗
PubMedDate not supplied

[Thermoregulating devices for artificial circulation apparatus with thermoelectric elements].

The increase of the absolute capacity of temperature control devices used in extracorporeal blood circulation apparatus has necessitated the intensification of heat exchange and, as a consequence, the work of heat exchangers under anisothermal conditions. This concerns mainly thermoelectric temperature control devices. Calculations in the process of their design and, to a greater extent, the optimization of their parameters under the conditions of anisothermality in the soldered joints become far more complicated. The numerical analysis of such thermoelectric device with anisothermal soldered joints has demonstrated the possibility of its analytical optimization by assuming it to be a thermoelectric device working under the average effective values of temperature and the coefficients of electrical characteristics. The results thus obtained allow to considerably decrease labor consumption in designing the above-mentioned devices.

Body Temperature Regulation↗