Peculiarities of the Development of the Myocardial Infarction in ISIAH Rats.

We studied peculiarities of the development of myocardial infarction in rats with inherited stress-induced arterial hypertension (ISIAH rats). The control group consisted of Wistar rats. Occlusion of the left coronary artery (30 min) followed by reperfusion (120 min) was performed. The infarct size was determined relative to the risk zone by staining with 1% triphenyltetrazolium. BP, blood filling, and blood flow in the caudal vessels were measured. The infarct size was 31.5±3.0% of the risk zone in Wistar rats and 47.9±4.4% in ISIAH rats (p=0.026). No correlations of infarction size and BP or HR were found at the study stages. In ISIAH rats, local 30-min ischemia followed by 120-min reperfusion caused greater myocardial infarction that did not depend on BP or HR.

[Myocardial Infarction and Natural Defense Mechanisms: The Role of Norepinephrine Reuptake].

PURPOSE: to study effect of norepinephrine reuptake blockade in reperfusion period on size of infarct caused by local ischemia with and without ischemic pre- and postconditioning. MATERIAL AND METHODS: Wistar rats (n=46) were randomly divided into 6 groups. Group (gr) I (n=7) - 30 min occlusion of left coronary artery followed by 120 reperfusion; gr II (n=2) as in gr I +desipramine (0.8 mg/kg intravenously [i.v.]) at the start of reperfusion; gr III (n=6) - ischemic preconditioning before coronary artery occlusion; gr IV (n=7).

Myocardial serotonin during ischemia under conditions of ischemic preconditioning.

We studied the dynamics of interstitial serotonin during local myocardial ischemia under conditions of ischemic preconditioning in Wistar rats. Ischemic preconditioning increased serotonin content in the dialysate (p=0.003). During 30-min ischemia, ischemic preconditioning delayed serotonin increase just before the 20th min of ischemia. Ischemic preconditioning promoted short-term increase in the serotonin level in the myocardial interstitium but followed by prolonged ischemia, it delayed the accumulation of serotonin in the myocardial interstitium.

Ischemic postconditioning and size of myocardial infarction during inhibition of norepinephrine reuptake.

We studied the effect of inhibition of norepinephrine reuptake during the reperfusion period on the size of infarction zone after focal myocardial ischemia and under conditions of ischemic postconditioning. In groups 1 and 2, 30-min occlusion of the left coronary artery followed by 120-min reperfusion was performed. In groups 3 and 4, ischemia was followed by ischemic postconditioning (six 10-sec occlusions alternating with 10-sec reperfusions). Ringer solution (1 ml, groups 1 and 3) and desipramine (0.8 mg/kg, groups 2 and 4) were injected intravenously at the beginning of reperfusion. The area of myocardial infarction in group 1 was 32.0±3.1% of the area of the risk zone; in groups 2, 3, and 4 the corresponding value was 46.1±3.4% (p=0.006), 22.2±2.6% (p=0.028), and 50.3±3.1% (p=0.018), respectively. It was shown that inhibition of norepinephrine reuptake in the early reperfusion period after ischemia increased myocardial injury and abolished the protective effect of ischemic postconditioning.

Inhibition of norepinephrine reuptake and size of myocardial infarction during focal ischemia and after preconditioning.

Experiments on rats showed that blockade of norepinephrine reuptake in the early reperfusion period after focal myocardial ischemia aggravates myocardial injury and abolishes the protective effect of ischemic preconditioning.

[Ischemic preconditioning and metabolism of myocardial adrenaline].

We implanted under urethane narcosis microdialysis probes into myocardium of Wistar rats. In experimental group we used ischemic preconditioning. After this left descending coronary artery was occluded for 60 minutes and then reperfused for 60 min. In control group prolonged occlusion was preceded by 30 min of rest. Significant elevation of noradrenaline concentration in myocardial interstitium was noted at 20th and 10th minutes of testing ischemia in experimental and control groups respectively. From 20th minute to the termination of occlusion noradrenaline concentration in myocardial in animals of control group was significantly higher than that in preconditioned animals. Concentration of dihydroxyphenylglycol in interstitium reflecting noradrenaline metabolism in axoplasm fell during ischemia and rose when reperfusion was started. Elevation of dihydroxyphenylglycol was statistically significant compared with both baseline level and control (p<0.005) practically at all stages of reperfusion. Thus ischemic preconditioning inhibits effectively noradrenaline accumulation in myocardial interstitium during prolonged ischemia. After ischemic preconditioning normal mechanism of noradrenaline reuptake functions longer however because of impaired storage in vesicles substantial part of noradrenaline remains in free state in axoplasm to be subjected to deamination with participation of monoamine oxidase.

[Role of norepinephrine in myocardial ischemia and ischemic preconditioning].

A brief preceding ischemia-reperfusion can reduce infarct size; this is known as ischemic preconditioning. During myocardial ischemia, massive norepinephrine is released from the cardiac sympathetic nerve terminals, reflecting the sympathetic nerve injury, and producing myocardial damage. However norepinephrine participates in myocardial protection during ischemia since its depletion in nerve terminals prevents ischemic preconditioning, and exogenous norepinephrine mimics ischemic preconditioning. Multiple-valued role of norepinephrine in myocardial ischemia, and ischemic preconditioning is discussed in review.

[Effects of the parameters of washing in Haemonetics Cell Saver 5 on the quality of the obtained erythrocyte mass at different rates of centrifuge rotation].

The aim of the investigation was to study effectiveness of washing autoblood by Cell Saver 5 (Haemonetics ) device in using different rates of washing and centrifuging. Autoblood was washed with 1000 ml 0.9% NaCl with different rates (500, 800 and 1000 ml/min) at different rates of centrifuge (5650 r/min and 4350 r/min). It was shown that Haemonetics Cell Saver 5 secured the optimum composition of the end product when using high rates of washing (800 and 1000 ml/min) and standard rate of the centrifuge rotation (5650 r/min).

[The cardiac performance recovery pattern and central hemodynamics in patients with coronary heart disease during coronary bypass surgery under extracorporeal circulation].

Central hemodynamic parameters were retrospectively studied in 284 patients. After aortic declamping, sinus rhythm spontaneously restored in 179 patients (Group 1), ventricular fibrillation occurred in 105 (Group 2). The preoperative parameters were similar in both groups. The number of grafts and the time of aortic clamping and cardiopulmonary bypass (CPB) were higher in Group 1. In the groups, the volume of cardioplegic solution and the average dose of phenylephrine and nitroglycerin per perfusion did not differ. After CPB, the values of cardiac output (CO) and cardiac index (CI) were significantly higher in Group 1 than in Group 2. At the end of an operation and 3 hours after its termination, there were no differences between two groups. Twelve hours after surgery, cardiac output and systolic blood pressure were significantly higher in Group 1. Following 24 hours of surgery, heart rate was significantly greater in Group 1 than in Group 2 After surgery, all hemodynamic parameters were within normal physiological values. The mean duration and the degree of inotropic support did not differ in the groups. The incidence of atrial fibrillation, perioperative myocardial infarction, and low cardiac output syndrome were comparable in both groups. Thus, various modes of cardiac performance recovery affect perioperative hemodynamics; however, this impact is insignificant and does not make management policy be changed in such patients. After aortic declamping, ventricular fibrillation requiring for defibrillation is not a clinical sensitive factor that negatively affects the intra- and postoperative period.

[Characteristic features of allogenic transfusions in elderly patients with ischemic heart disease in operations under conditions of extracorporeal circulation and using cell saver].

It was shown that in spite of using different methods of saving the autologous patient's blood, cell saver included, in elderly patients operated upon under conditions of extracorporeal circulation the frequency and volume of allogenic transfusions was higher as compared with the younger patients, in elderly women the allogenic transfusions being necessary more frequently.

[The oxygen-transport function of blood in reconstructive operations on the aorto-femoral segment and application of high molecular hydroxyethyl starch].

The prospective randomized investigation included 71 patients with obliterating atherosclerosis of the lower extremities with chronic ischemia. Planned operations of aorto-bifemoral shunts were made. Patients of the first group (n=43) were treated by infusion therapy including solutions of colloids and crystalloids. In the second group a solution of high molecular hydroxyethyl starch was used in addition to colloids and crystalloids. Transfusion of the allogenic components of blood was made in the both groups according to the indications. The parameters of the oxygen-transport function of blood were studied before initial narcosis, under conditions of general anesthesia before the beginning of operation, in 60 minutes of reperfusion after finishing the aorto-femoral shunting, and in a day after operation. It was shown that using the solution of high molecular hydroxyethyl starch promoted the elevated level of the delivery and consumption of oxygen as compared with the standard infusion-transfusion therapy which is explained by the predominantly hemodynamic component of the oxygen transport.

[Low doses of aprotinin in reducing blood loss and allogenic transfusions in operation under conditions of extracorporeal circulation with using cell saver].

A blind prospective randomized investigation included 109 patients with ischemic heart disease undergoing operations of coronary shunting under conditions of extracorporeal circulation. It was shown that aprotinin in the dose of 3 ppm KIU in operations of coronary shunting under conditions of reserving autoblood, extracorporeal circulation and using cell saver facilitates reducing postoperative blood loss, but does not lead to less frequent allogenic transfusions.

Corticosteroid and immune responses to cardiac surgery.

Serum corticosteroid-binding globulin (CBG) and cortisol levels as well as subsets of circulating immunocompetent cells (ICCs) were measured during cardiac surgery. Closed heart surgery (closed mitral commissurotomy) resulted in an elevation of cortisol levels (up to 32 +/- 5 micrograms/dL by the end of the surgery) with no changes in CBG and ICC levels observed. Open heart surgery (open reconstruction of the mitral valve) in surface-induced hypothermia (without extracorporeal bypass) caused a dramatic drop in CBG activity (from 250 +/- 17 microM before the beginning of anesthesia to 198 +/- 15 microM by the end of cooling (just before cardiac arrest) and 158 +/- 13 microM after 30 min of reperfusion), whereas cortisol levels were only slightly elevated by the end of cooling, and a significant increase (up to 17 +/- 2 micrograms/dL) was observed only at the end of the surgery (60 min of reperfusion and warming). Similar to CBG, a significant decline in circulating ICC contents occurred in response to cooling and circulatory arrest.

[Emergency craniocerebral hypothermia in the management of open mitral commissurotomy]. / Ekstrennaia kraniotserebral'naia gipotermiia v obespechenii otkrytoi mitral'noi komissurotomii.

Craniocerebral hypothermia was used during open-heart surgery in 69 patients with mitral stenosis (hospital mortality rate 2.9%). Indications for open-heart surgery (left atrial thrombosis, mitral valve calcinosis, onset of traumatic mitral insufficiency) were determined intraoperatively during closed mitral commissurotomy. Some pathophysiological peculiarities of craniocerebral hypothermia were studied. A decrease in brain temperature and total oxygen consumption (up to 27.7% of the basic metabolism level) has been observed. Prolongation (up to 25 min) of major vessel occlusion had no negative effect on the patients' condition, postoperative complications and lethality. Craniocerebral hypothermia is considered to be a safe and effective technique indicated in case of emergency for open-heart surgery.

[Effects of intraoperative reservation and reinfusion of autologous blood on the function of lungs in patients with ischemic heart disease]. / Vliianie intraoperatsionnogo reservirovaniia i reinfuzii autokrovi na funktsii legkikh u bol'nykh ishemicheskoi bolezn'iu serdtsa.

A retrospective examination of 127 patients has been performed who underwent operations of coronary bypass under conditions of hypothermic extracorporeal circulation. It was shown that both the reservation of autoblood (volume about 10% of circulating blood) and the following reinfusion failed to result in a substantial change of the lung functions. The reservation-reinfusion of autoblood in IHD patients operated on by direct revascularization of the myocardium under conditions of extracorporeal circulation did not influence the indices of ventilation (the volume of functional dead space), pulmonary blood flow (fraction of venoarterial intrapulmonary shunt, mean pressure in the pulmonary artery), diffuse capacity of the lungs (the arterial/alveolar ratio).

[The low cardiac output syndrome after valve-conserving operations under hypothermia without perfusion]. / Sindrom nizkogo serdechnogo vybrosa posle klapanosokhraniaiushchikh operatsii v usloviiakh besperfuzionnoi gipotermii.

Under study were the frequency of occurrence and causes of development of the syndrome of low cardiac output after the saving correction of mitral defects under conditions of cranio-cerebral (1st group-80 patients), general moderate (2nd group-130 patients) and deep hypothermia (open mitral commissurotomy-3rd group of 134 patients and reconstructive operations on the mitral valve-4th group of 104 patients). Frequency of development of the complication was reliably higher in groups with deep hypothermia (1.25% of patients in the 1st group, 9.2% in the 2nd group, 27.6% in the 3rd group, 25% in the 4th group). Factors influencing the development of the low cardiac output syndrome in patients of the 2nd group was duration of the disease, in the 3rd group patients-the class according to the classification of the New York cardiological association and age of the patient, in operated patients of the 4th group it was the value of the cardio-pulmonary coefficient. Pharmaco-ice-chip cardioplegia used in patients of the 3rd and 4th groups failed to decrease frequency of the development of the low cardiac output syndrome in the postoperative period.

[Blood oxygen transport function during ftorotan application in patients with ischemic heart disease and low cardiac output]. / Kislorodotransportnaia funktsiia krovi pri primenenii ftorotana u bol'nykh ishemicheskoi bolezn'iu serdtsa so snizhennym serdechnym vybrosom.

A total of 41 patients with ischemic heart disease (IHD) were retrospectively examined after coronary bypass grafting under the conditions of extracorporeal artificial blood circulation and with a combined anesthesia involving ftorotan. The patients were divided into two groups: group 1--11 patients with an initial cardiac index below 33 l x min-1 x m-2 (3.8 +/- 0.27 l x min-1 x m-2. Group 2--30 patients with an initial cardiac index below 2 l x min-1 x m-2 (1.7 +/- 0.04 l x min-1 x m-2, p < 0.01 as compared to group 1). As for group 1, there were reduced parameters, noted at the examination stages, in the oxygen-transport blood function, while they were found to be increased in group 2. Combined anesthesia with ftorotan was not found, in IHD patients with an initial low-output cardiac state, to disrupt essentially the oxygen transport during the pre-perfusion stage. The dynamic changes of the oxygen-transport parameters were shown to be related, in pre-perfusion stage, mainly with peculiarities of hemodynamic changes, in the early operative stage, in patients with different initial cardiac output states.

[Components of anesthesiological provision and central hemodynamics in hypothermia without perfusion]. / Komponenty anesteziologicheskogo obespecheniia i tsentral'naia gemodinamika pri besperfuzionnoi gipotermii.

Central hemodynamics was studied by thermodilution in 16 patients with acquired mitral defect during surgery under conditions of hypothermia without perfusion. Cooling and surgical correction were carried out under superficial ether anesthesia with morphine and droperidol. A 28% decrease of the minute circulation volume is observed as early as under general anesthesia and at the very beginning of cooling (10.8% more); this decrease is caused by rarer heart contractions and increase of the total peripheral vascular resistance as a result of body response to cool exposure. An almost 10 degrees C drop of body temperature (to 27.2 +/- 0.2 degrees C) involves a just 13% decrease of the cardiac index in comparison with the value at the beginning of cooling. Injection of droperidol before cooling blocks the increase of the total peripheral resistance in a dose-dependent mode (about 0.13 mg/kg of droperidol is needed for sufficiently complete prevention of the increase of total peripheral resistance), and thus maintains the stroke and cardiac indexes at a sufficiently high level. Morphine (in doses of up to 2.3 mg/kg) did not bring about such an effect.

[A case of long-term occlusion in craniocerebral hypothermia]. / Sluchai dlitel'noi okkliuzii v usloviiakh kraniotserebral'noi gipotermii.

A case of urgent application of craniocerebral hypothermia (CCH) during correction of traumatic mitral insufficiency developing in the course of closed mitral commissurotomy is described. The occlusion duration was 46.5 min, with the temperature in the esophagus 30.2 degrees C. No postoperative neurological disturbances have been observed. Three years after surgery the patient was in a satisfactory condition. It is demonstrated that CCH is associated with a more marked antihypoxic effect, than it has been earlier believed, and that it is possible to use intravenous ketamine anesthesia during CCH in patients with low cardiac output syndrome.

[Methods to decrease the blood loss during operations under hypothermia without perfusion]. / Sposoby snizheniia krovopoteri pri operatsiiakh v usloviiakh besperfuzionnoi gipotermii.

The work analyzes causes of high blood loss in operations under conditions of nonperfusion deep hypothermia. It was found to be related with the division of massive adhesions in the preocclusive period and with the presence of prolonged heparinemia after occlusion. A combination of a minimal trauma of adhesions, reliable surgical hemostasis, early suturing the wound of the chest and early neutralization of activity of heparin allowed the operation blood loss to be 2.4 times less and the postoperative blood loss--2.7 times less.