Nonpharmacologic management of cardiac arrest and cardiogenic shock.
Explore the source record for details and available documents.
Cardiac Surgical Procedures↗
SEARCH · PubMed Health
Results for “Heart-Assist Devices”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
[Heart transplantation--indications and results].
Heart transplantation has become a standard procedure in the treatment for irreversible heart failure. Criteria for both recipients and donors have been extended. One year survival now reaches 81%. In the immediate postoperative course patients are endangered by infection. In the long-term course coronary artery disease of the transplanted heart becomes the most serious problem. Alteration of liver and kidney function due to chronic medication as well as malignancies and hypertension also occur. In case of chronic transplant failure retransplantation may be indicated. Acute cardiac failure before transplantation nowerdays can be treated by mechanical circulatory assist devices.
Follow-Up Studies↗
[Schemes for implanting shovel pumps for assisted circulation].
The authors propose a design of an axial shovel pump for extracorporeal circulation. They show how to introduce it into various cardiovascular segments and make a comparative assessment of its efficacy in relation to the type and severity of heart failure, surgical access, and treatment policy.
Assisted Circulation↗
New approaches for cardiac assists: "back to the future".
The treatment of the modern epidemic of coronary artery disease requires the availability of various cardiac assist devices. A review and future implications of the use of retrograde coronary venous perfusion, the intraaortic balloon, a new ascending aortic pump, variable atrial septal defect, and novel energy sources are discussed.
Aged↗
The relationship between organ perfusion pressure and multiple organ failure during mechanical left ventricular assist.
The purpose of this study was to analyze the relationship between hemodynamics, especially the organ perfusion pressure (OPP = mean aortic pressure-mean right atrial pressure) and multiple organ failure (MOF) in cardiac patients receiving left ventricular mechanical assists (LVA). The subjects were 33 patients who had undergone left ventricular mechanical assists in the Department of Cardiovascular Surgery, Fukushima Medical College Hospital, from March 1985 through March 1990. OPP significantly correlated with the levels of GOT, total-bililubin (TB), BUN and serum-creatinin (s-Cr), oxygenation index (OI) and respiratory index (RI). The cardiac index and left and right ventricular stroke work indices, in comparison with OPP, did not significantly correlate with any of the above laboratory tests. These results indicate that OPP is a simple and reliable index to recognize, and also to prevent MOF during LVA. It was also found that OPP should be maintained at a level higher than 65mmHg to protect the liver, kidneys and lungs.
Adult↗
[High incidence of left ventricular thrombosis and systemic embolism in patients with left ventricular assist system].
The purpose of this study was to determine the incidence of left ventricular (LV) thrombosis and systemic embolism in 14 patients with LV assist systems. Echocardiography was used to detect LV wall motion abnormalities, intracavitary smoke-like echoes and thrombosis, and the effect of anticoagulant therapy was serially examined. During full assist of the circulation, the aortic valve did not open in any patient. Smoke-like echoes were observed in 9 patients (64%) and thrombi in 8 (57%). The thrombus developed within the first 3 assist days. Systemic anticoagulant therapy decreased the thrombus size in only 3 patients, but there was a possibility of intracranial or mediastinal bleeding in other 3 patients. Systemic embolism was noted in 7 of 11 autopsy patients (64%). The characteristic finding was that there were multiple embolized organs, such as the brain, kidneys, spleen and liver, in all patients. Development of a thrombus is a serious complication in all patients with LV assist systems. However, the problem does not lie in the assist system but in the left ventricle of the patient's own heart. It is also noteworthy that systemic anticoagulation is not effective for an LV thrombus. A new method of assisting the failing heart, or a new anticoagulant delivery technique for the LV cavity to prevent LV thrombus development is needed.
Adult↗
Mechanical circulatory support in the 1990s.
The current experience in bridging patients to weaning (more than 965 implants) and to transplantation (more than 544 implants) has shown the feasibility of mechanical circulatory support in patients with major cardiac dysfunction, who are unresponsive to optimal medical management. The complications are mostly related to the patient's initial condition at the time of implantation. The rehabilitation of the patient is related to both the extent of recovery from organ dysfunction and the type of device. This analysis proposes some new orientations for research. Firstly, in clinical research, definition of precise indices of the patient condition, not exclusively related to the haemodynamic situation, should allow better patient and device selection. Secondly, in technological research, precise definition of the actual clinical objectives should help in the development of various systems: for resuscitation, for bridging purposes and for long-term or permanent implantation.
Assisted Circulation↗
Management of the patient awaiting cardiac transplantation.
The spectacular clinical success of heart transplantation (HTTX) in the cyclosporine era has engendered challenging new clinical problems that include long-term management of patients with severely compromised systolic function, preparation of potential HTTX recipients for major surgery followed by immunosuppression, and ethical and rational distribution of limited numbers of donated organs. The magnitude of these challenges may seem overwhelming. Fortunately, clinicians have the luxury of dealing with the issues involved one patient, and one step, at a time. The continued efforts of clinical investigators have clarified important management principles. There is a growing appreciation of the pivotal importance of mitral valve function in determining the response to medical therapy and long-term prognosis in this patient population. Enthusiasm for pharmacologic control of asymptomatic ventricular ectopy has waned; instead, the restoration and maintenance of normal atrial function has clearly taken precedence. In preparation for surgery, new endoscopic techniques offer great advantages. The use of high-technology support devices as "bridges to transplantation" has been re-examined in view of the relatively poorer short- and long-term prognosis of patients managed with these devices. Increasingly, the optimal scenario for HTTX entails transplantation of a severely compromised but medically stable patient. As specific therapy, HTTX today has relatively limited application to the vast majority of patients with heart failure (HF). Seventeen hundred heart transplants will do little to directly affect the 400,000 patients in the United States who each year develop symptomatic HF.(ABSTRACT TRUNCATED AT 250 WORDS)
Anticoagulants↗
Electromechanical artificial heart with a new gear type and angled pump chambers.
The intrathoracic anatomical situation after explantation of the natural heart defines the maximum available space for the design of the housing as well as of the inlet- and outlet connectors of a fully implantable electromechanical artificial heart. Based on computer-assisted anatomical studies, a total artificial heart housing is designed which facilitates an oblique orientation of the pumping chambers for a better fluidmechanical and anatomical arrangement of the in- and outlet connectors. The pumping chamber geometry is based on modifications of an existing cardiac assist-system. Subsequently a mechanical gear which conforms to this anatomically adapted housing is developed.
Heart, Artificial↗
Dynamic pumping performance of the Hemopump--a small intraventricular blood pump.
We studied the pumping characteristics of the Hemopump, a commercially available miniature intraventricular blood pump for temporary support of failing hearts. The Hemopump is an axial flow pump of which the characteristics can be described by turbomachine theory. Experiments with water and a mock circulation verified that the pumping characteristics of the Hemopump in terms of both pressure head and flow as a function of rotational speed, very well can be described by a first order differential equation. The influence of blood with its non-Newtonian character is being investigated.
Heart-Assist Devices↗
[A case of acute right ventricular infarction and life-saving right ventricular assistance following emergency coronary revascularization and resection of a left ventricular aneurysm--discussion of indication and proper assist flow volume].
Right ventricular assistance (RVA) using centrifugal pump in combination with IABP was used to treat a patient who was difficult to wean from a cardiopulmonary bypass following emergency coronary revascularization and resection of a ventricular aneurysm performed to treat acute right ventricular infarction due to a PTCA complication. After 131 hours of RVA at 3.2 to 4.8 l/min, it was possible to remove the pump. No heparin was administered during this time, changing the pump head twice, was used for 64 and 50 hour period, no thrombi were detected either time. After being weaned from RVA, the patient developed severe respiratory dysfunction, but on the 10th postoperative day (POD) IABP was weaned, and on the 13th POD the artificial respirator was withdrawn. The results of the postoperative cardiac catheterization were favorable, the patient was discharged on the 57th POD, and has returned to society at the present time. The indications for RVA include a central venous pressure > 20 mmHg and a cardiac index < 1.8 l/min/m2, and tissue perfusion pressure and general preoperative condition should severe as guides. The higher the assisted flow volume the more efficacious in relieving ventricular load, but, since there is a limit to how much the left ventricle and lungs can withstand, it should not exceed levels which ensure the maintainance of cardiac output and tissue perfusion pressure.
Angioplasty, Balloon, Coronary↗
The HeartMate: a left ventricular assist device as a bridge to cardiac transplantation.
Explore the source record for details and available documents.
Animals↗
Mechanical circulatory support: a necessary adjunct to a cardiac transplantation service.
Explore the source record for details and available documents.
Follow-Up Studies↗
Cardiopulmonary transplantation service establishment in the 1990s: Australia--a developing country?
1. A National Transplantation Service has been established at the Alfred Hospital performing more than 50 transplants per year. 2. Increased access to transplantation technology has facilitated an improvement in national population servicing from 2.7 to 6.2 transplants per million population per year. National funding of A$4.062 million per year has been secured. 3. Basic research into organ preservation has facilitated transcontinental organ procurement. 4. An active lung transplantation program has been established synchronous with the cardiac transplant service activities. 5. MCS program establishment has paralleled clinical transplantation activities. 6. Budget management and cost containment has been achieved through rationalisation of management protocols.
Australia↗
[Place of the autologous myoneoventricle in the evolution of the methods of assisted and replacement blood circulation in critical conditions of the pumping function of the heart].
Explore the source record for details and available documents.
Critical Care↗
A new skeletal muscle linear-pull energy convertor as a power source for prosthetic circulatory support devices [corrected].
Previous studies show that stimulated skeletal muscle wrapped around the heart or a blood pumping pouch can provide partial circulatory assistance. However, skeletal muscle is accustomed to pulling in direct tension, and power obtained from using the muscle in wraparound configurations is very inefficient. Therefore we have developed a new skeletal muscle-powered, linear-pull energy convertor for powering a wide range of implanted devices, including circulatory support blood pumps such as counterpulsation devices or complete prosthetic ventricles. This energy convertor system is powered by a skeletal muscle such as the latissimus dorsi, which is stimulated with a pulse generator. With the muscle left intact and in situ as much as possible, its insertion at the humerus is removed and reattached to a small-cylinder hydraulic energy convertor that is firmly attached to the ribs. Mechanical force in direct tension from the muscle is converted to high-pressure, low displacement; hydraulic energy (at approximately 200 psi). The output of this hydraulic energy convertor is connected by a small-diameter tube to a hydraulic actuator to drive the pusher plate of an implantable ventricular assist device located in the thoracic cavity or abdomen or another suitable blood pump. Preliminary in vitro tests from an engineering model of the Thoratec muscle-powered ventricular assist device show flow outputs of 5.2 L/min at a mean arterial pressure of 99 mm Hg. The muscle-powered ventricular assist device is a specific application designed to provide completely implantable circulatory support as an alternative to heart transplantation. It will enable patients to experience a quality of life free from batteries and the electrical power-conditioning hardware required with electromechanical systems.
Bioelectric Energy Sources↗
Fundamental rhythm of sympathetic nerve discharges in animals with total artificial hearts.
To evaluate the effect of total artificial heart replacement on the autonomic nervous system, sympathetic neurograms were analyzed by power spectrum and coherence function. Two pneumatically driven, sac type ventricular assist devices were implanted as biventricular bypasses (BVB) in adult, mongrel dogs. After initiation of BVB pumping, the natural heart was electrically fibrillated to form a BVB TAH model. Renal sympathetic nerve activity (RSNA) was recorded using a bipolar electrode attached to the left renal sympathetic nerve. RSNA was amplified and integrated by use of an R-C integrator. Power spectra of the RSNA and values of squared coherence between the arterial pressure wave form and the RSNA were calculated by computer. In animals with total artificial hearts (TAHs), coherence at the cardiac rhythm frequency was decreased, and coherence at the TAH pumping rhythm frequency was increased. These results indicate that the arterial pulse wave observed in TAH animals contributed to the sympathetic neurogram.
Animals↗
[A cardiodynamic study on cardio-assistive effect of the assist device: evaluation on left ventricular dehematizing system].
Of late years, assist artificial heart device has been more and more investigated with subsequent reports being made of its clinical application. Dehematization of left ventricular assist device (LVAD) is divided into two systems, i.e., left atrial dehematization and left ventricular dehematization according to the location of the canula's tip. At present in our country, the former system is being adopted for the majority of LVADs and is generally regarded as preferably acceptable. However, because of low survival rate of LVAD in spite of its comparatively good rate of break-away, not a few cases appear to exist beyond the limit of the former system's effects. Then, compared with the left atrial dehematizing system, LVAD according to the left ventricular dehematizing system was examined for its cardio-assistive effect both blood circulatorily and cardiodynamically. A pneumatically-driven diaphragm type pump was implanted between the left ventricular apex and the descending aorta of a dog and was driven by ECG-synchronous counterpulsation method with heart rate versus pump beating number ratios of 1:1, 2:1 and 4:1 and fixed beating number method with beating number of 60 and 80 beats/min (bpm). In order to measure the left ventricular diameter and myocardial length, 7 pairs of ultrasonic sonomicrometers were embedded intra-left ventriculomurally. Ischemia was prepared by ligating the left anterior descending coronary artery (LAD). Bulk mechanical work and regional mechanical work were calculated from these dimensions and the left ventricular pressure. The following results were obtained: 1) In all driving modes but that of 4:1, compared with non-driven pumping, heart rate, peak left ventricular pressure, mean left atrial pressure and total peripheral resistance showed low values, and mean aortic pressure and total blood flow showed high values. Moreover, in the above driving modes, total bypass was obtained. 2) In the above driving modes, bulk and regional mechanical works were practically null with a de-loading effect of 100% or so being obtained. 3) Compared with the left atrial dehematizing system, peak left ventricular pressure showed remarkably low value with increases in mean aortic pressure and total blood flow, and with remarkable decreases in bulk and regional mechanical works. 4) In driving modes of 2:1, 1:1, I60 and I80, little difference in the effect according to the driving mode was noted.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗