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At least 73 records · Page 4Linked to original sources
PubMed1977

[Massive mitral insufficiency due to spontaneous and isolated rupture of a posterior papillary muscle. Echocardiographic study, treatment by assisted circulation and prosthetic valve replacement].

The authors report a case of a patient of 72 years of age in whom the sudden onset of severe left ventricular failure led to the discovery of massive mitral incompetence. The diagnosis of rupture of the posterior papillary muscle of the mitral valve, which was suggested on clinical and echocardiographic grounds, was confirmed at operation. This was carried out after 72 hours of assisted circulation by counter-pressure, and consisted of a replacement by a prosthetic valve. The authors emphasise, in the light of this case, the importance of echocardiography by ultrasound in the early diagnosis of this type of acute mitral incompetence, clarify the signs, and emphasise the part played by assisted circulation with an intra-aortic balloon in the treatment of this condition.

Aged↗
PubMed1981

[Heart replacement (biventricular assisted circulation) with the ellipsoid heart (E-BVAD) (author's transl)].

At the present time mechanical assisted circulation is indicated in patients with cardiac failure after open heart operations. The results after clinical implantation of the left ventricular assist devices are not encouraging. However, most of these patients suffer from irreversible cardiac failure and no restitution is to be expected. In patients with postoperative cardiac failure, a distinction must be made between isolated left heart failure and total heart failure. In patients with total heart failure - for example with diffuse, marked coronary sclerosis - both left and right ventricle failure exists. In these patients, no left ventricular assist device per se can bring the desired effect, since due to the right heart failure syndrome, the left system does not work adequately. With the biventricular bypass it is possible to maintain complete circulation in cases of cardiac insufficiency. The cannulation concept is biventricular transatrial to the aorta or to the pulmonary artery. The technique is simple and can be carried out very quickly. In cases of clinical emergency this device can be recommended due to the satisfactory haemodynamic effects achieved and the small degree of traumatic haemolysis. It represents an easy and quick implantable system for total functional heart replacement.

Animals↗
PubMedDate not supplied

[Certain technical aspects of assisted circulation].

The paper treats of issues concerned with the control, designing of the drive and operating mechanisms of the equipment for assisted circulation, working on the principle of an oriented presure change in the cardio-vascular system. Problems relating to the cardiosynchronization of the therapeutic action, constructing a drive based on the use of a linear direct current motor and to the demands placed on the actuating mechanisms are discussed.

Assisted Circulation↗
PubMed1994

Assisted circulation in postcardiotomy heart failure: experience with the Bio-Medicus centrifugal pump in ten patients.

Between January 1990 and September 1992, ten patients required assisted circulation for postcardiotomy heart failure which was unresponsive to inotropic drugs and aortic counterpulsation. All patients were supported by a Bio-Medicus centrifugal pump (biventricular assist in five, left ventricular in three, right ventricular in two); six had ischaemic heart disease, two a congenital ventricular septal defect, one an acute mitral valve incompetence and one an aortic type 'A' dissection. The mean duration of circulatory support was 5.1 days (range 2 hours to 8 days). Six patients were weaned from the device and four were discharged; the perioperative deaths among the patients weaned from support were the result of cerebral haemorrhage and multiorgan failure respectively. No late deaths occurred at a mean follow-up of 15 months. Common complications were bleeding (40%), acute renal failure (30%) and sepsis (30%). All patients who developed renal failure died. The high incidence of haemorrhagic complications makes the use of pre-heparinized circuits desirable as these patients do not then require additional anticoagulation.

Acute Kidney Injury↗
PubMedDate not supplied

Platelet glycoprotein IIb/IIIa inhibitor attenuates complement activation during in vitro ventricular assist circulation.

Complement activity and platelet glycoprotein (GP) IIb/IIIa dysfunction have been demonstrated during in vitro ventricular assist device circulation. Platelets contain C1 serine protease inhibitor (C1 INH) in secretory granules, which normally regulates complement. Complement activity may result from a loss of platelet regulation on complement during ventricular assist device circulation as platelets lose viability. The purpose of this study was to assess the ability of a platelet GP IIb/IIIa receptor inhibitor to attenuate ventricular assist device associated complement activation during in vitro ventricular assisted circulation. Eight in vitro nonpulsatile centrifugal ventricular assist device circuits were simulated for 4 days using 450 ml fresh human whole blood. Cardiac index, temperature, pH, PO2, PCO2, Ca, glucose, and activated clotting time were maintained at physiologic levels. Levels of C1 INH and C3a were measured with and without a reversible glycoprotein IIb/IIIa inhibitor (MK-383). Concentrations of C1 INH increase on exposure to ventricular assist device, and decrease to a plateau within 12 hr. The decrease in circulating unbound C1 INH was attenuated with pre treatment with MK-383. Concentrations of C3a increase 34 fold within 4 hr of exposure to a ventricular assist device with and 22 fold without pre treatment with MK-383. These findings suggest that protection of the platelet GP IIb/IIIa complex delays complement activation during in vitro ventricular assist device circulation.

Complement Activation↗
PubMed1981

Infection in remnant of left ventricular assist device after successful separation from assisted circulation.

There have been two long-term and two short-term survivors among 10 patients in our hospital in whom the left ventricular assist device (LVAD) was implanted for cardiogenic shock after cardiac operations. Two of these four patients developed graft infection in the LVAD remnants left attached to the ascending aorta and left ventricle; one died of sepsis and the other required repeat operations for a chronic draining sinus and hemorrhage from a left ventricular--cutaneous fistula. This experience with infection and demonstration of the feasibility of total removal of both limbs of the LVAD without cardiopulmonary bypass lead us to recommend complete removal of the LVAD conduits in patients weaned from assisted circulation.

Aorta↗
PubMed1992

Recent advances in assisted circulation using centrifugal pump in surgical and non-surgical patients with acute heart failure or related conditions.

During the last 3 years, left or bi-ventricular support using a centrifugal pump as a ventricular assistance device was performed in 10 patients after open heart surgery. The basic lesions were coronary heart disease in 8 and valvular disease in 2 patients. Bypass support ranged in time from 33 to 240 h (average 114 h), and 3 patients received biventricular support. Six patients have survived in this group. Other supportive methods, in the form of emergency or elective use of portable cardiopulmonary bypass support, were used in 8 patients; 4 with cardiogenic shock and 4 for supported percutaneous coronary angioplasty. These assisted circulations appear to be useful and promising in the management of the critical cardiac patient.

Adolescent↗
PubMedDate not supplied

[The sinus VK experimental apparatus for assisted circulation].

Presented in the paper is the unit for cardiosynchronized extra- and intracorporal control in the course of the intensive therapy of patients with acute cardiac failure. It provides several methods of the assisted circulation and can be used in clinical cardiology, surgery and reanimation departments. Main specifications, the structure and the principle of functioning are given. The prototype testing has shown that "CHHyc B K" can be used to advantage in clinical practice and should be introduced for the full - scale production.

Assisted Circulation↗
PubMedDate not supplied

Split-circulation assist device facilitates heart failure management and increases effects of intra-aortic balloon pumping.

The split-circulation assist device (SCAD) comprises an intra-aortic balloon pump (IABP), percutaneous cardiopulmonary support (PCPS) equipment, and two occlusion balloons that occlude the descending thoracic aorta by alternate inflation. With the SCAD, the failing heart, assisted by IABP, maintains only the upper 25-30% of the entire circulation without any interference by bypass flow from PCPS. An animal experiment indicated that a given rise in cardiac output caused an increase in aortic pressure in the SCAD group about three times greater than that in the control group (an ordinary combination of IABP and PCPS). Thus, by causing greater increases in arterial pressure, the SCAD may make possible detection of subtle increases in cardiac output, and therefore early detection of cardiac recovery. Multiple regression analysis from the pressure and flow data obtained in another experiment indicated that the SCAD facilitated the prediction of cardiac outputs and loads by preventing the bypass flow rate from influencing the aortic pressure. In addition, the SCAD may enhance cardiac assistance by increasing the effects of IABP. Therefore, the SCAD is a useful and potent new circulatory assist device that can facilitate both timely weaning from PCPS and heart failure management.

Animals↗
PubMedDate not supplied

[Computer monitoring of hemodynamics during assisted circulation and extracorporeal detoxication in abdominal surgery].

Basic central and regional hemodynamic parameters have been studied using a computer monitoring system in 57 patients with acute abdominal surgical diseases during special extracorporeal procedures. Indications for regional assisted circulation (RAC) as well as regularities in hemodynamic changes during and after procedures have been established. The data of monitoring have shown that RAC and RAC in combination with hemosorption have in most cases a marked favourable effect on abdominal hemodynamics: mesenteric and portal blood flow is increased and consequently total hepatic flow is activated. The flow of portal blood leads to an increase in central venous pressure. Unfavourable tendencies have been established in changes of central hemodynamics during the procedures. They are: calculated intervals of the rates of central venous pressure increment and cardiac output decrement. This made it possible to optimize the use of extracorporeal procedures in patients with such diseases.

Abdomen↗
PubMed1981

Assisted circulation by phasic external lower body compression.

Assistance to the systemic venous circulation after experimental acute bypass of the right heart was provided by phasic external compression of the body. Pressure to 60 mm Hg administered to the body below the costal margin at 6--8 cycles/min augmented the circulation by translocation of blood volume from the peripheral to the central circulation, which increased right atrial pressure by 44%, mean cardiac index (61 to 74 m/kg/min) and mean arterial pressure (79 to 100 mm Hg) by 21%. The experimental study was followed by clinical trial of this method of circulatory support after anastomosis of the right atrium to the pulmonary artery (Fontan operations) in nine patients. One-minute cycles of phasic external compression of 45--50 mm Hg for 45 seconds followed by decompression for 15 seconds in patients increased right atrial pressure by 44% (mean increase 7 mm Hg) and systolic arterial pressure by 30% (average 20 mm Hg, range 13--28 mm Hg). Only two patients required inotropic medications; the others received either no medications or nitroprusside during the first 24 hours after surgery. Phasic external compression of the lower body is a simple and effective means of assisting the circulation after the Fontan operation.

Adolescent↗
PubMedDate not supplied

Mechanisms of red blood cell trauma in assisted circulation. Rheologic similarities of red blood cell transformations due to natural aging and mechanical stress.

Clinical experience with circulatory support devices has typically shown alteration of patient blood rheology exhibited through increasing blood viscosity and decreasing erythrocyte deformability. Our hemorheologic studies have additionally shown a remarkable increase in red blood cell (RBC) aggregation in the blood of artificial heart patients as compared to healthy donors. These hemorheologic changes may be caused by mechanical trauma to RBCs. The authors hypothesize that the mechanical trauma process, from a rheologic point of view, could be analogous to an "accelerated" RBC aging process. The hypothesis was examined through in vivo and in vitro experiments on RBCs, age-separated on the basis of density, specifically to identify the rheologic similarities between aged and mechanically traumatized RBCs. Older RBCs demonstrated an increased mechanical fragility, a decreased deformability, and a increased ability to aggregate as compared to younger RBCs. RBCs exposed to mechanical stress demonstrated similar alterations in the same rheologic parameters. Our experiments have also shown that mechanical stress decreases the negative surface charge of RBCs as is known to occur in aged RBCs. Similarities found between the processes of RBC mechanical trauma and senescence enhance our understanding of mechanisms of subhemolytic trauma incurred in assisted circulation. This may improve the design and evaluation of future heart assist devices through minimizing shear induced blood trauma.

Animals↗
PubMedDate not supplied

A new method of assessing left ventricular function under assisted circulation using a conductance catheter.

A new method of assessing left ventricular (LV) systolic function without terminating assisted circulation (AC) was investigated using a LV volume catheter (conductance catheter) in canine cardiopulmonary bypass (CPB) (Group 1, n = 7) and left heart bypass (LHB) (Group 2, n = 5) models. The hearts were subjected to either 20 min of global ischemia (IS), with a subsequent 80 min of reperfusion under CPB, or regional IS under LHB. Instantaneous LV pressure-volume data acquisitions were repeated during transient (15 sec) acute volume loading without terminating bypass. The relationship between the stroke work (SW), determined as the area of the pressure-volume loop, and the end-diastolic volume (EDV), were highly linear at every study point (mean: r = 0.956-0.986 in Group 1, r = 0.974-0.987 in Group 2). The slopes of SW and EDV (preload recruitable stroke work: PRSW) significantly decreased after IS, in both Group 1 and Group 2. In conclusion, measurement of PRSW without terminating bypass seemed to be useful in evaluating LV systolic function in patients under AC.

Animals↗