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At least 433 records · Page 24Linked to original sources
PubMed1979

[The efficacy of the intra-aortic balloon pump for patients with heart failure complicating acute myocardial infarction (author's transl)].

Assisted circulation was carried out with the help of an intra-aortic balloon pump in 22 patients with acute transmural myocardial infarction and heart failure (despite medication). Two patients died in hospital. The combination of the balloon pump and nitrates proved to be particularly effective. The follow-up examination of the survivors showed a distinct pulmonary arterial pressure during ergometry. All of the examined patients revealed extensive akinetic and diskinetic areas, significant stenosis being detectable either in the proximal area of the Ramus descendens anterior or in two or three blood vessels.

Adult↗
PubMed2006

Study on mechanical circulatory support and currently available supporting parts in China.

The research and development on extracorporeal and assisted circulation in China have been painstaking. On one hand, China has the largest population of 1.3 [corrected] billion in the world, and the demands for supporting equipment are huge. On the other hand, as a developing country, China is not wealthy. It is urgent to design and fabricate affordable circulatory support parts, machines, and artificial hearts for Chinese market. In this regard, we have made our own heart-lung machine, mechanical and tissue valves, oxygenators, and artificial hearts and their improved versions. The cost of these parts is much lower as compared with those in the Western market. Although the results of clinical application are good so far, the quality of these lifesaving parts needs to be continuously improved.

Assisted Circulation↗
PubMed1982

[Counterpulsation in clinical practice].

A. N. Bakulev Institute of Cardiovascular Surgery, Academy of Medical Sciences of the USSR has 10 years of experience with counterpulsation in 209 patients with acute cardiac insufficiency. The main indications for assisted circulation were cardiogenic shock in 102 patients, myocardial infarction complicated by cardiac insufficiency in 43, cardiac insufficiency developing during or after cardiosurgical operations in 60 cases, prophylaxis of complications in high risk patients during intracardiac methods of investigation in 4 cases. The use of counterpulsation in 102 patients with post-infarction cardiogenic shock enabled the authors to liquidate the shock in half of the cases and to discharge 20% of the number from hospital. The study of peculiarities of shock enabled the authors to trace measures for decreasing mortality rate: use of counterpulsation as early as possible during transportation to hospital (29 cases), extension of indications for urgent surgery on the heart.

Assisted Circulation↗
PubMed1977

[Value of intra-aortic counterpressure as circulatory support in cardiac surgery. Apropos of 60 cases].

Assisted circulation (AC) by intra-aortic counterpressure (IACP) has been used in 60 patients either pre- and postoperatively after a complication of acute myocardial infarction (25 patients: group A), or for a low-output syndrome after extracorporeal circulation (ECC) occurring in the operating theatre (20 patients: group B), or secondarily (15 patients: group C). In group A cases, the IACP stabilised a the myocardial ischaemia, and permitted coronary arteriography and subsequent surgery with little risk. Out of the 8 patients in this group who had cardiogenic shock only 4 survived, whereas out of the 17 patients without shock, only one died. Of the group B and C patients, 58% responded favourably to IACP, and 75% of group B cases survived as against 33% of group C. The postoperative low-output syndrome is related not to the ECC itself but to ischaemia of the subendocardial vasculature during surgery. The incidence of this syndrome can be reduced by the use of improved techniques of myocardial protection. AC by means of IACP becomes an effective therapeutic weapon if it is used early, or even systematically when the ejection fraction is below 0.03 and/or the EVR is less than 0.80.

Adult↗
PubMed1993

Circulatory assist techniques in cardiogenic shock: metabolic aspects.

Assisted circulation in severe cardiogenic shock was evaluated using a reservoir and a single pump without an oxygenator in 88 dogs. Study groups included: no treatment, substrates only (cysteine, ribose), nitroprusside, left ventricular (LV) + right atrial (RA) bypass + substrates, LV + RA bypass, left atrial (LA) + RA bypass, LA bypass, LV bypass, LV + RA + fluosol. Metabolic studies of O2 consumption, acid and alkaline phosphatase, lactate, creatine phosphokinase (CPK), myocardial depressant factor (MDF), and tissue adenosine triphosphate (ATP) were done in the course of 4-hour treatment periods followed by 2-hour observation periods. Best survival at 4-hour and 6-hour levels were achieved in LV + RA bypass. Cysteine and ribose reduced survival when added to the pump supported (LV + RA bypass) group. Cysteine/ribose improved survival over the no treatment group. O2 consumption increased significantly in the groups with best survival but remained unchanged from control or shock levels when cysteine/ribose were added. Unusually high levels of CPK, acid and alkaline phosphatase, and MDF occurred in both groups receiving cysteine/ribose, indicating significant organ damage correlating with poor survival. Lactate levels were less predictive. Heart tissue ATP levels were higher in groups with good survival. Liver ATP levels were lower in high survival groups. Lung ATP did not differ between groups.

Acid Phosphatase↗
PubMed2000

Extracorporeal circulation in ewe's foetus: towards a reliable foetal cardiac surgery protocol. A comparison of two cases.

UNLABELLED: Foetal cardiac surgery is the ultimate goal in the treatment of congenital cardiac malformations. The aim of our research is to elucidate some of the features of the necessarily invasive experimental protocol to be used in an animal model of foetal cardiac surgery. In particular, we assessed the foetal placental reactivity to prolonged cardiac bypass in steady-flow conditions. METHODS: Two cases were selected to show the outcome of prolonged (> 30 minutes) extracorporeal circulation (ECC) instituted without oxygenator under steady-flow assistance. Following the instrumentation of the animal (placement of pressure, flow and myocardial fiber length transducers) and the baseline recordings, a 60-minute bypass period was established with an axial turbopump (Hemopump 14 Fr), after systemic heparinisation and artero-venous cannulation. At the end of the circulatory assistance, the cannulae were removed and a 90 minute observation period followed. The cardiac function was assessed by means of indirectly obtained P-V loops. RESULTS: Case A showed a marked reduction in the end-systolic pressure-volume relationship (ESPVR) during ECC, corresponding to a rightward shift of the P-V loop, with a gradual recovery after the assisted circulation. On the contrary, case B was subjected to progressive placental dysfunction, as evidenced by haemogasanalytical data. Consequently, the haemodynamic data also outlined a negative outcome, with high ESPVR values after bypass. CONCLUSIONS: The present study, while confirming the possibility of cardiac intervention in the foetus, underlines the critical role of minimally invasive protocol to limit both foetal stress and placental dysfunction.

Animals↗
PubMed1982

[Sterilization of the artificial blood circulation apparatus with ozone].

Presented in this paper is the sterilization method of the assisted circulation unit. The method has been approved by stand testing and then applied for sterilizing the unit Ae, yeK-5 m when experimental implanting artificial heart. According to the method, ozone in concentration of 5 x 10(-3) moles/1 and with flow rate of 0,5 1/min is passed through an internal circuit of the unit during I h and 15 min. Control wash-out samples from lines have demonstrated complete sterility of the internal circuit. The method makes the sterilization process of such units much easier and may be recommended for clinical application.

Heart, Artificial↗
PubMed1993

[Surgery for thoracic aortic aneurysm by retrograde total body perfusion and deep hypothermia].

We performed retrograde total body perfusion and deep hypothermia for DeBakey III aortic dissection and aneurysm of the distal arch. We could operate with only posterolateral skin incision using a long venous cannula, which is originally a part of percutaneous cardiopulmonary support (PCPS). The duration of retrograde total body perfusion was 31-101 minutes, the perfusion volume 0.6-1.4 L/min, the central venous pressure 5-16 mmHg. All five cases were successfully operated. As a postoperative cerebral accident, one case showed transient dysfunction. There was no postoperative liver and renal dysfunction. The perfusion volume was maintained in 2.5-3.0 L/min during ventricular fibrillation, which is occurred in cooling and rewarming process. So, this long venous cannula worked well to assist circulation. We think retrograde total body perfusion is a useful assisting device for DeBakey III aortic dissection and aneurysm of the distal arch.

Aged↗
PubMed1990

Computer simulation of the mechanically-assisted failing canine circulation.

A model of the cardiovascular system is presented. The model includes representations of the left and right ventricles, a nonlinear multielement model of the aorta and its main branches, and lumped models of the systemic veins and the pulmonary circulation. A simulation of the intra-aortic balloon pump and representations of physiological compensatory mechanisms are also incorporated in the model. Parameters of the left ventricular model were set to simulate either the normal or failing canine circulation. Pressure and flow waveforms throughout the circulation as well as ventricular pressure and volume were calculated for the normal, failing, and assisted failing circulation. Cardiac oxygen supply and consumption were calculated from the model. They were used as direct indices of cardiac energy supply and utilization to assess the effects of cardiac assistance.

Animals↗
PubMed1991

First clinical implantation of the BCM 3.5 ventricular assist device (VAD).

We report on the first human implantation of the BCM 3.5 ventricular assist device in a 46-year-old man suffering from terminal stage cardiomyopathy. The circulatory support was used as a bridge to heart transplantation. The patient was in cardiogenic shock and was on assisted circulation for 18 days after which he underwent cardiac transplantation. While receiving support from the ventricular assist device, the patient's condition improved remarkably and 50 days after transplantation he was discharged from hospital. We give a detailed description of the surgical technique, with special emphasis on the procedures for air extraction. We describe the evolution of the hemodynamic status before and after implantation. Final inspection of the device and cannulae after removal showed no thrombi and only small fibrin deposits in the membrane-wall junction.

Cardiomyopathy, Dilated↗
PubMed1996

Effect of pulsatile and nonpulsatile assist on heart and kidney microcirculation with cardiogenic shock.

To estimate microcirculation of the heart and kidney in pulsatile and nonpulsatile-assisted circulation, a comparison study was done using a swine model. Acute myocardial infarction was made by ligation of the left coronary artery branches. After cardiogenic shock, animals were divided into 3 groups as follows: Group C (n = 6), no assist provided; Group NP (n = 6), assisted by a nonpulsatile pump (Bio-Medicus BP-80); Group P (n = 6), supported by a pulsatile pump (Nippon Zeon). left coronary artery flow, endocardial and epicardial regional flows, and renal cortex and medulla tissue blood flows were measured. Left coronary artery flow and endocardial and epicardial tissue blood flows decreased in cardiogenic shock, and they recovered to the control level soon after support in both Group N and Group P. Renal medulla and cortex tissue blood flows decreased in cardiogenic shock, and these flows did not recover in either Group N or P. However, cortex blood flow in Group P did improve, but it did not improve in Group N. These results suggested that pulsatile assist was more effective than nonpulsatile assist for microcirculation after cardiogenic shock to avoid deterioration of major organ functions.

Animals↗
PubMed1987

[Middle molecule compounds of the plasma in heart surgery patients in operations with artificial circulation and blood ultrafiltration].

Venous plasma middle molecule compounds (MMC) were determined in 63 cardiosurgical patients, operated on for acquired heart diseases or coronary disease, with assisted circulation (AC) and with or without blood ultrafiltration (BUF). Intraoperative MMC level was superior to that of normal donors, and tended to decrease during AC, while BUF had basically no effect on MMC content, in spite of the latter's withdrawal with the ultrafiltrate.

Adolescent↗
PubMed2004

Weaning of rotary blood pump recipients after myocardial recovery: a computer study of changes in cardiac energetics.

BACKGROUND: Weaning of patients from mechanical cardiac support after myocardial recovery has always involved multiple, interacting factors, particularly the training of the myocardium during reduction of pump flow. Rotary pumps offer training advantages when support flow is reduced, even to nearly zero. We report a computer analysis that evaluates the work required of the heart during partial unloading and removal of rotary pumps. METHODS AND RESULTS: A computer model of the assisted circulation, previously implemented in MATLAB (The MathWorks Inc, Natick, Mass), has been augmented with a model of the MicroMed DeBakey ventricular assist device (MicroMed Technology, Inc, Houston, Tex). Flow, pressure patterns, and external work (pressure-volume area, calculated as the area of the ventricular pressure-volume loop [external work] plus potential energy) were calculated for nonassisted and various continuously assisted patients. Under low-flow conditions, the heart imposes an oscillating forward-backward flow through the non-occlusive rotary pump, causing an increase in ventricular work. Thus, an assist flow of 1 to 1.5 L/min requires work equivalent to that of the unsupported heart. At 60% contractility, the nonassisted pressure-volume area is 1.10 Ws/beat, and the potential energy is 0.38 Ws/beat. At a Qpump of 1 L/min, the pressure-volume area is 1.21 Ws/beat, and the potential energy is 0.37 Ws/beat. At a Qpump of 3 L/min, the pressure-volume area is 0.93 Ws/beat, and the potential energy is 0.29 Ws/beat. These conditions cannot be achieved with pulsatile systems. CONCLUSION: During weaning and retraining, an implanted rotary pump can provide a workload to the heart like that in the nonassisted situation, thus increasing the predictability of weaning and reducing the risk of reiterating heart failure.

Cardiovascular System↗
PubMed1987

A compact centrifugal blood pump for extracorporeal circulation: design and performance.

A new compact centrifugal blood pump driven by a miniature DC servomotor has been designed for use for short-term extra corporeal and cardiac-assisted circulation. The impeller of the pump was connected directly to the motor by using a simple-gear coupling. The shaft for the impeller was sealed from blood by both a V-ring and a seal bearing. Either pulsatile or nonpusatile flow was produced by controlling the current supply to the motor. The pump characteristics and the degree of hemolysis were evaluated with regard to the configuration of the impeller with a 38-mm outer diameter in vitro tests; the impeller having the blade angles at the inlet of 20 deg and at the outlet of 50 deg was the most appropriate as a blood pump. The performance in an operation, hemolysis and thrombus formation in the pump were assessed by a left ventricular bypass experiment in dogs. It was suggested by this study that this prototype pump appears promising for use not only in animal experiments but also in clinical application.

Animals↗
PubMed1966

Survey of mechanical assistance of the circulation and the present status of left-heart bypass.

The various types of mechanical circulatory assistance which recently have been developed are described. The techniques which appear to be most promising for clinical application are: veno-arterial bypass with oxygenation, synchronous arterial assistance, and closed-chest left-heart bypass.The effects of a left ventricular bypass on central hemodynamics and the oxygen requirements of the left ventricle are described. A bypass of 90% of the left ventricular output brings about a 30% reduction in the left ventricular myocardial oxygen requirement. Left atrial pressure is reduced. The central aortic mean pressure, the pulmonary artery pressure, and the right atrial pressure are not changed.

Animals↗
PubMed1997

Pre-clinical evaluation of a novel, pneumatic, ventricular assist device (Medos HIA-VAD) under pathophysiological conditions.

To evaluate a new cardiac assist system, the Medos HIA-VAD, we studied the effects of mechanical unloading on regional and global myocardial dysfunction. As a model for the regional temporary contractile dysfunction we chose an anesthetized, open chest preparation in sheep. We occluded the diagonal coronary artery for 15 minutes and reperfused for 90 minutes. Hemodynamic parameters and wall thickening were monitored. Unloading with the 60-ml Medos HIA-VAD was performed either during ischemia (group II) or during reperfusion (group III). The recovery of non-uniformity indicated by post-ejection wall thickening was significantly faster (p < 0.05) in both groups if compared to the non-assisted group (group I) (all groups n = 4). Recovery of systolic wall thickening in the postischemic region in group I was only 76 +/- 12%, while it was 103 +/- 11% and 92 +/- 11% in groups II and III, respectively (p < 0.05). In a canine model of global left ventricular failure, we occluded the left anterior descending coronary artery for 20 min, and after 5 minutes of reperfusion, the circumflex artery for 45 min (group I, n = 5). After 5 min of CX occlusion in group II we performed assisted circulation for 90 min with the 10-ml (n = 5) and the 25-ml (n = 5) Medos HIA-VAD. In group I, no dog survived, in group II, all survived 4 hours of reperfusion (n = 10). Lactate at the end of the experiment was 1.1 +/- 0.9 mmol/L (10-ml, and 1.1 +/- 0.2 mmol/L (25-ml) (p > 0.05 vs. base line). We conclude that the Medos HIA-VAD is a reliable assist device that enhances myocardial recovery and allows sufficient peripheral circulation in the case of cardiogenic shock.

Animals↗
PubMedDate not supplied

[Liver circulation during acute cardiac insufficiency and the use of intra-aortic balloon counterpulsation].

Liver hemodynamics was experimentally studied in a model of acute heart failure caused by successive ligation of coronary artery branches and the following cardiogenic shock and during assisted circulation using intraaortic balloon contrapulsation. It has been established that intraaortic balloon contrapulsation promotes to the elimination of hemodynamic liver disturbances, however no final recovery of the organ hemodynamics was observed after 2 hours of contrapulsation. The method of intraaortic balloon contrapulsation is recommended at early stages of acute heart failure prior to the onset of profound ischemic changes in the liver.

Acute Disease↗