Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Assisted Circulation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources
PubMed1978

[Heart operations on young children under deep hypothermia].

The authors discuss their clinical experience in the use of deep hypothermia in combination with auxiliary extracorporeal circulation. Operations were performed on 124 children (total mortality 23.4%). Lowest mortality was noted in correction of ventricular septal defect; 12 out of 82 patients died, which accounts for approximately 14.6%. A follow-up of the remote results shows that the method has no harmful effect on the central nervous system.

Assisted Circulation↗
PubMed1993

Update on skeletal muscle ventricles as aortic diastolic counterpulsators.

Skeletal muscle ventricles are constructed from canine latissimus dorsi muscle. These skeletal muscle ventricles can be placed subcutaneously on the chest wall or inside the chest cavity. Skeletal muscle ventricles are connected to the descending thoracic aorta and activated to pump blood as aortic diastolic counterpulsators. The skeletal muscle ventricle in 1 animal pumped blood in the circulation for 27 months. Skeletal muscle ventricles can also function effectively under the condition of low cardiac output. Although thrombus has been detected in some skeletal muscle ventricles, thromboembolism to distal organs has been detected only rarely during the past few years. This research appears promising; however, skeletal muscle ventricle rupture remains a problem and currently accounts for about 30% of the mortality in the long-term experiments. It occurs at the site between the skeletal muscle ventricle outlet and the Dacron sewing ring that is necessary to connect conduits from the skeletal muscle ventricle to the animal's circulation. We believe that skeletal muscle ventricle rupture is likely to be a solvable problem. Once a solution has been found, skeletal muscle ventricles may be ready for clinical use in patients with chronic congestive heart failure.

Animals↗
PubMed1983

[Experimental and clinical use of artificial heart ventricles].

The paper sums up experience with the development of a domestic system for auxiliary circulation and a module-type artificial ventricle, and presents the results of their experimental trial and first-ever clinical use in patients with severe heart failure following open-heart surgery. Good operational characteristics and high efficiency of this equipment in clinical as well as experimental terms are demonstrated.

Adult↗
PubMed1981

[Venoarterial perfusion without oxygenation as a means of mechanical aid to the heart in acute failure].

The efficacy of veno-arterial perfusion without oxygenation was established in experiments on dogs with a model of acute cardiac insufficiency. The overall index of circulation and the percentage of the heart participation in it is an important criterion of the effectiveness of shunting of the left ventricle. This criterion made it possible to determine the therapeutic role of veno-arterial perfusion without oxygenation in aiding the diseased ventricle even when the size of the shunt did not exceed 1/3 of the initial cardiac ejection.

Acute Disease↗
PubMed1976

Transapical left ventricular bypass (TALVB) without an auxiliary ventricle.

A simple transapical left ventricular bypass system employing a roller pump, transapical LV withdrawal catheter, and outflow filter for continuous blood filtration, has been developed and evaluated in unanesthetized sheep for periods beyond 2 wks. The system provides continuous partial LV bypass and is capable of totally maintaining the circulation in the presence of a vasodilator or when total bypass is desired. Blood damage is minimal and blood transfusions have not been required. The transapical withdrawal catheter has been left in the LV apex beyond 4 mos and demonstrates thrombus formation and myocardial histological changes which suggest this catheter should be removed after pumping or long-term anticoagulation provided.

Animals↗
PubMed2006

[Influence of extracorporeal circuits surface on hemostasis system during off-pump surgeries].

It is demonstrated that special surface of extracorporeal circuit promotes reduction of artificial circulation negative influence on hemostasis system. During artificial circulation coating "duraflo" gradually loses its protective characteristics due to washout of heparin molecules from the surface of extracorporeal circuit, whereas chemical link between heparin and protein in "safe-line" coating is more stable. The results of the study demonstrate no advantages of heparin coating of extracorporeal circuits over protein one. Finally, all the advantages of extracorporeal circuits with "safe-line" coating lead to a decrease of postoperative blood loss.

Assisted Circulation↗
PubMedDate not supplied

Skeletal muscle ventricles with a single-limb conduit: the importance of hemodynamic design.

BACKGROUND: Skeletal muscle ventricles (SMVs) connected to the descending thoracic aorta have the potential for providing long-term diastolic augmentation. A successful existing design employs a bifurcated conduit, but aortic constriction between the limbs of the conduit is required to ensure obligatory flow-through. Here we evaluate an alternative approach in which connection to the aorta is made by a single-limb conduit. METHODS: In two groups of dogs SMVs were constructed from the left latissimus dorsi muscle and connected to the circulation via a single-limb conduit of length 110-120 mm (Group 1, n = 5) or 70 mm (Group 2, n = 5). The animals were followed over 10 weeks. RESULTS: Although all animals showed significant augmentation of diastolic aortic pressure at the outset, substantial thrombus developed in the SMVs of both groups. The results were analyzed by reference to design criteria for a single-limb conduit SMV, developed from empirical, in-vitro flow studies and formulated mathematically. CONCLUSION: The SMVs constructed in this experiment appeared to meet the criteria for adequate mixing of blood within the ventricle. They did not, however, achieve adequate exchange of blood with the circulation. Thrombosis was therefore attributable to excessive residence time of blood in the SMV and conduit. Both the experimental study and the mathematical analysis point to the need for SMVs of this configuration to be constructed closer to the aorta. Preliminary results are reported for such an experiment in the pig, in which the SMV was thrombus-free when terminated electively after 1 week.

Animals↗
PubMed1976

The artificial heart - progress, problems, and further development.

The state of the art in the development of artificial heart research based on more than 100 own animal experiments and information from the other groups working in the same field is laid out. Consideration is given to a variety of special problems. The use of biomaterials (blood compatibility and mechanical strength and durability), the flow pattern in the pumps (clot formation), and special hemodynamical effects are discussed as well as different driving systems and percutane energy transmission (avoidance of infection). Respective measurements show the hemodynamics in the systemic and pulmonary circulation, especially the difficulties of the venous inflow and the regulation of the pumps. The effect of an active artificial atrium and new ways of computerized regulation using noninvasively measured parameters are described. Other pathophysiologic findings (lung, kidney, acid-base metabolism, gastrointestinal tract, blood) are dealt with according to their importance. The miniaturization of the driving system and new methods of energy supply necessary for a totally implantable artificial heart system, envisaged for the future, are also pointed out.

Adaptation, Physiological↗
PubMedDate not supplied

Acute phase responses of vasoactive hormones to non pulsatile systemic circulation.

Acute phase responses of vasoactive hormones to the rapid conversion of a systemic flow pattern from pulsatile or non pulsatile mode to the reverse were assessed in 20 goats weighing 45-69 kg. A total left heart bypass was instituted under general anesthesia, with pulsatile and non pulsatile pumps interposed in the circuit in parallel, and the systemic flow mode was rapidly and bidirectionally converted from the pulsatile mode or non pulsatile mode to the reverse. Vasoactive hormone levels and hemodynamics were evaluated before and after 5 min of conversion. No significant difference was observed between the modes either in blood flow or systemic vascular resistance, while the mean aortic pressure was significantly higher in the non pulsatile mode than the pulsatile mode (106.7 +/- 2.4 versus 99.9 +/- 3.5 mmHg). Among various vasoactive hormone levels evaluated, only norepinephrine showed a significant difference between the modes, where concentration in the non pulsatile mode was significantly higher than the pulsatile mode (391.0 +/- 60.7 versus 309.4 +/- 42.5 pg/ml). No correlation was found between the absolute values of mean aortic pressure and norepinephrine level, whereas a significant reciprocal correlation was detected between the magnitude of inter-mode differences in these two parameters. In conclusion, a non pulsatile systemic circulation does not exert significant influence on vasoactive hormone levels, except for slight increase in norepinephrine with a reciprocally correlated increase in mean aortic pressure. It is deduced that activity of the sympathetic nervous system represented by norepinephrine level is higher in the non pulsatile mode than the pulsatile mode, and the baroreceptor reflex functions in an acute phase after flow mode conversion.

Acute-Phase Reaction↗
PubMed1976

[Use of intra-aortic balloon in cardiac surgery].

Use of the intra-aortic balloon in the treatment of circulatory failure after cardiac surgery has resulted in the long-term survival of 7 patients out of 20. The failures occured when the myocardium is severely compromised so that any treatment is likely to fait (8/13), and where there is the ultimate complication of renal or hepatic failure (4/13), irreversible ventricular failure or secondary haemorrhage. In urgent coronary bypass surgery (4/13) it would appear that the use of the balloon preoperatively would have avoided or at least slowed the progress toward the anatomical changes of massive infarction. As the use of the balloon has often been associated with a reduction in the number of circulating platelets and a pathological increase in the breakdow products of fibrin, heparin is now used systematically in an attempt to prevent the development of a true intravascular coagulation syndrome. The use of lidocaine is also recommended to prevent fatal or dangerous ventricular arrhythmias when the balloon is functioning well. A combination of the intra-aortic balloon with the infusion of small doses of adrenaline would seem to be an interesting therapeutic combination, especially at the onset of counterpressure.

Arrhythmias, Cardiac↗
PubMedDate not supplied

Current status of circulatory support with an intra-aortic balloon pump.

Although the initial clinical application of IABP was for the purpose of support of circulation in cardiogenic shock, its indications have expanded and include prophylactic use, especially in patients with ischemic heart disease. Controversy exists regarding the efficacy of this device in these conditions. Prolonged balloon support for periods of more than 5 days is presently employed in patients with chronic heart failure undergoing cardiac surgery, without concern for so-called "balloon dependence." In recent years, the incidence of use of IABP has declined markedly mainly because of comparable effects obtained by hemodynamic treatment with various drugs aimed at altering a specific parameter of cardiac function. Percutaneous application of an intra-aortic balloon catheter, although associated with a higher complication rate, has brought to clinical practice a rapid method for utilization of this device under fluoroscopic control. Because of an appreciable number of complications, however, balloon assist should be used for very specific clinical conditions.

Arrhythmias, Cardiac↗
PubMed2000

[A simultaneous operation on coronary artery disease and abdominal aortic aneurysm during extracorporeal circulation in patient with impaired left ventricular function].

A 74-year-old man had an previous antero-septal and inferior myocardial infarction and an abdominal aortic aneurysm (AAA) 48 mm in diameter. Coronary angiography showed obstruction of the left anterior descending artery and of the right coronary artery, and 95% stenosis of the circumflex artery. The value of an ejection fraction of the left ventricle was 33%, measured by left venticulography. CABG and replacement of the aneurysm were performed simultaneously, because of the necessity of an intra-aortic balloon pumping (IABP) due to the impaired left ventricular function. First, CABG was performed under cardiac arrest. After declamping the ascending aorta, subsequently, replacement of AAA was performed while extracorporeal circulation (ECC) assisted heart beating. Weaning from ECC was smooth, and the operation was successful without using IABP. The patient was discharged 32 days after the operation. Consequently, cardiopulmonary bypass during AAA operation could decrease heart loads when hemodynamic states change in aortic clamping or after declamping. A simultaneous operation of CABG and AAA using ECC is safe and effective for impaired left ventricular function.

Aged↗
PubMedDate not supplied

[Changes in indicators of brain metabolism in heart surgery patients under normal and hypothermic perfusion].

Metabolism of the brain was studied in 82 cardiosurgical patients operated on under conditions of hypothermal and normothermal artificial circulation (AC). The principal differences in the pattern of changes of cerebral metabolism were observed at the stage of heart connection to the bloodflow, corresponding to the period of warming during hypothermal AC. The detected reduction of oxygen extraction and arteriovenous glucose difference in the normothermal group may be a result of cerebral bloodflow shunting, and more pronounced stimulation of free-radical processes be indicative of the possible injury to cerebral structures in the absence of protective effect of hypothermia.

Adult↗
PubMed1993

Coronary and circulatory support strategies for percutaneous transluminal coronary angioplasty in high-risk patients.

PTCA is now applied to patients with unstable acute ischemic syndromes, severe multivessel coronary artery disease, and impaired left ventricular function. To minimize the risk during angioplasty, several coronary and systemic circulation support approaches have been developed as adjuncts to high-risk angioplasty. Local coronary support techniques include the perfusion balloon catheter, the coronary stent, directional coronary atherectomy, laser balloon angioplasty, perfluorocarbon coronary perfusion, coronary sinus retroperfusion, and distal coronary hemoperfusion. Systemic circulatory support includes intraaortic balloon counterpulsation, cardiopulmonary support, the hemopump, and left heart partial bypass. These support devices, while associated with significant complications, may ultimately improve the safety of coronary angioplasty and allow its application to those who would otherwise not be candidates for revascularization.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

[Evaluation of the safety of auxiliary venous drainage in the surgical treatment of patients with acquired cardiac diseases].

The present study has comparatively analyzed two procedures of auxiliary venous drainage: 1) that by means of vacuum (VaVD), 2) that using an additional roller pump (ARP) and the conventional extracorporeal circulation (EC) with gravitation venous drainage (GVD). The material for the study was the number of microembolic signals (MES) in the middle cerebral artery bed and neurological disorders in patients operated on for cardiac valvular diseases. According to the venous drainage procedure, the patients (n = 90) were divided into 3 groups: 1) those (n = 30) with traditional GVD; 2) those (n = 30) with VaVD; 3) those (n = 30) with ARP. The study revealed the impact of different venous drainage procedures on the number of MES and the patients' neurological status.

Adolescent↗
PubMed2001

A mathematical model of the fetal cardiovascular system based on genetic algorithms as identification technique.

The development of fetal cardiac surgery, considered the ultimate goal in the treatment of congenital cardiac malformations, needs to be supported by detailed knowledge of the blood circulation in the fetal cardiovascular system. The hemodynamic behavior in distal territories is usually inferred from vessel resistance indices, which give limited physiological information. This study presents a mathematical model of the human fetal global cardiovascular system, developed to clarify the relationships and differences existing between upper and lower body circulation. We modelled the heart with two time-varying capacitances, each representing the respective ventricle's pressure-volume relationship. The fetal vascular system was represented using two six-element Windkessel models, for the upper and lower body respectively. We obtained the identification of the set of circuital and elastance function parameters of the model using Genetic Algorithms (GAs), which follow the laws of evolutionary theory. We compared the results of our numerical study on the model identified with data collected from measurements and literature, to validate the proposed global cardiovascular system model of the human fetus. This model is intended as an instrument to investigate the differences in blood distribution between the different vascular districts in the upper and lower fetal body and the role of the aortic isthmus, the small tract of vessel connecting upper and lower fetal vascular beds; it may also represent a useful tool in the assessment of dynamic balance during mechanical assistance of circulation.

Algorithms↗
PubMed1985

[Experimental studies on the problem of improving the myocardial blood circulation in an intraoperatively resuscitated heart].

A pumping system for supporting an intraoperatively failured heart is presented. This system consists of a bell-shaped receptacle for the heart and a pump with a working volume of 49 ml and a working pressure of 220 Torr. The pumping power is transmitted to the heart by means of an external pneumatic pressure line. The efficacy of the pump in the high pressure system amounted to 20-30 per cent. An effective coronary perfusion in case of a cardiac failure is guaranteed by a venous underpressure pump of this pumping system. A favourable influence was also observed in case of the low pressure system.

Animals↗
PubMed1975

[Experimental studies on the circulation of the vascular area of the subdiaphragm using a newly developed pulse-wave pump].

A new developed partial artificial heart system is presented, which allows pulsatile perfusion of vital organs. The results presented reveal the possibility to duplicate pressure curves and peak systolic pressure in the perfused area-similar to physiological preoperative measurements. The kidney function remains intact. Angiographically there is no damage of the kidney vessels evident. The results are compared with datas of other investigators. Especially there opinion about the disturbance of renal flow and function under nonpulsatile conditions are critically evaluated. A possible connnection between the postoperative renal failure after cardio-pulmonary bypass and non-pulsatile perfusion and other pathophysiological mechanisms are discussed.

Abdomen↗