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PubMedDate not supplied

Acute right ventricular failure following heart transplantation: improvement with prostaglandin E1 and right ventricular assist.

Development of significant pulmonary hypertension following orthotopic heart transplantation can result in death caused by irreversible right ventricular failure. Despite determination of acceptable preoperative pulmonary vascular resistance, this complication may still occur. This report illustrates the technique of right ventricular assist and concomitant infusion of intrapulmonary prostaglandin E1 for the treatment of postoperative right ventricular failure resulting from pulmonary hypertension.

Acute Disease↗
PubMedDate not supplied

Temporary ventricular support. Current indications and results.

Current data indicate that temporary ventricular support in patients who cannot be weaned from cardiopulmonary bypass is a reasonable and therapeutic treatment to extend life. Ventricular recovery and quality of life are satisfactory in long-term hospital survivors, and noncardiac disability is rare. Although the role of temporary ventricular support for acute myocardial infarction and cardiogenic shock is undefined, the expansion of indications to include these patients is reasonable and future clinical trials are warranted. Additionally, there is sufficient evidence to indicate that temporary mechanical support is useful as a bridge to heart transplantation. The superiority of one support system over another in any given clinical instance can only be settled after the results of continued and carefully controlled clinical experiences have been reported.

Adult↗
PubMed1987

Percutaneous cardiopulmonary bypass with a synchronous pulsatile pump combines effective unloading with ease of application.

Percutaneous total cardiopulmonary bypass offers the advantage of rapid, simple implementation without the need for thoracic incision and provides the ability to support both left and right ventricular failure as well as pulmonary insufficiency. Previous studies using roller pump percutaneous bypass were only partially successful because of the inability to effectively unload the left ventricle. In the present experiment we attempted to determine in a normal canine model whether use of synchronous pulsatile pumping for percutaneous bypass could overcome this problem. Fourteen dogs were placed on percutaneous bypass for 1 hour. A roller pump was used in seven and a synchronous pulsatile pump with an electrocardiogram triggering mechanism in the other seven. All animals were maintained on percutaneous bypass for 1 hour. In the pulsatile pump group there was a significantly greater percent decrease from baseline in tension-time index (-56.3% versus -19.1%, p less than 0.01) and in myocardial oxygen consumption (-45.8% versus +2.1%, p less than 0.05) and a significantly greater percent increase in the endocardial/epicardial blood flow ratio (27.6% versus -6.5%, p less than 0.01) than in the roller pump group. These results show that superior unloading can be achieved by percutaneous pulsatile bypass compared with percutaneous roller pump bypass. The findings suggest that percutaneous total cardiopulmonary bypass with a synchronous pulsatile pump offers a relatively simple but effective method for providing appropriate patients with temporary hemodynamic stability before cardiac catheterization or medical or surgical revascularization.

Animals↗
PubMed1985

Experimental evaluation of complete electrically powered ventricular assist system.

The LVAS utilizing an intrathoracic blood pump and a parathoracic, electrohydraulic energy converter has a number of promising features. These include: transcutaneous energy transmission and an implanted variable volume device which eliminate the need for percutaneous access; utilization of an intrathoracic blood pump and variable volume device which allow the diaphragm and abdominal cavity to remain intact; parathoracic or subcutaneous location of the transformer secondary, energy converter, internal battery and interconnecting elements allowing replacement with a minor surgical procedure; employment of the "biolized" continuous blood contacting surface which has the potential of long-term use without anticoagulants and utilization of an electrohydraulic energy converter which provides synchronization without requiring transducers and associated electronics and which provides lubrication of mechanical components. The development effort, which began separately in 1977 and has been conducted jointly by Nimbus and the Cleveland Clinic since 1980, has demonstrated that the above features can be incorporated in a reliable LVAS. In particular, the system in vivo test series have demonstrated the soundness of the basic concepts and led to refinements which were demonstrated in the 6-1/2 mo test. All elements of the system have been utilized during the in vivo test program. Component tests of significance include: LVAS and total heart blood pump in vivo experiments of up to 7 mos duration which demonstrate the blood compatibility of the biolized surface without the use of long-term anticoagulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Current strategy of circulatory support for profound heart failure.

The purpose of this study is to assess the current strategy of mechanical circulatory support for profound heart failure. In the last 10 years, 37 patients with profound heart failure underwent mechanical circulatory support after open heart surgery and 9 patients with non-cardiotomy cardiogenic shock received emergency circulatory support. All patients showed severe cardiac failure and/or fatal ventricular arrhythmia and required circulatory support as a life-saving measure. After cardiovascular surgery, 12 of those patients underwent venoarterial bypass (VAB), 13 had biventricular bypass (BVB), 8 had left ventricular bypass (LVB) and the remaining 4 patients received left ventricular assist device (LVAD). And 9 patients with non-cardiotomy cardiogenic shock received percutaneous cardiopulmonary support (or PCPS) as an emergency assist system. Weaning and discharge rates of the patients by the type of circulatory supports were 41.7% and 25.0% with VAB, 69.3% and 46.2% with BVB, 87.5% and 37.5% with LVB, 75.0% and 50.0% with LVAD, and 44.4% and 11.1% with PCPS, respectively. Clinical results of post-cardiotomy circulatory support (64.9% of weaning and 37.8% of discharge) were acceptable, but the patients with non-cardiotomy cardiac failure needed early application of more advanced circulatory support.

Adult↗
PubMed1994

Implantation technique for the Novacor left ventricular assist system.

The Novacor left ventricular assist system (Baxter Healthcare Corp., Novacor Div., Oakland, Calif.) is currently undergoing clinical investigation as a bridge to cardiac transplantation. The original animal and clinical protocols recommended placement of the pump/energy converter within the peritoneal space. During preclinical cadaver fitting trials, we determined that it might be difficult to place this device in the peritoneal cavity of tall, slender patients, patients having a small muscular abdomen, and many women. We were also concerned that peritoneal placement would increase the risk and severity of infection and that abdominal organs might be injured by direct contact with the pump. In studies in cadavers, we therefore developed a technique using preperitoneal placement of the pump/energy converter. This technique has now been used successfully in more than 200 patients. A detailed description of this insertion technique is presented to facilitate its current use for the implantation of temporary devices and to plan for the implantation of permanent systems.

Assisted Circulation↗
PubMedDate not supplied

Portable cardiopulmonary support system as a bridge to left ventricular assist system implantation. A new strategy for the treatment of end stage cardiac disease.

The key to the successful implantation of a left ventricular assist system (LVAS) for patients with end stage cardiac disease is whether the functions of other vital organs are irreversibly damaged or not. The portable cardiopulmonary support system (PCPS) is not only as convenient as, but is more powerful than, the intra-aortic balloon pump (IABP) in resuscitating impaired end organ function. To investigate the efficacy of PCPS in end stage cardiac disease, end organ function before and after the application of PCPS was retrospectively analyzed for end stage cardiac disease. From 1992 to 1996, five cardiomyopathy patients with deterioration in end organ function, despite application of IABP, underwent PCPS support before implantation of LVAS. Urine volume and levels of liver enzymes (sAST and sALT) and serum creatinine were determined before and after institution of PCPS. After the start of PCPS, the urine output increased significantly (1,840 +/- 450-4,340 +/- 470 ml/day, p < 0.01), and levels of sAST, sALT, and serum creatinine decreased significantly (630 +/- 220-150 +/- 50 IU/L, 630 +/- 260-260 +/- 130 IU/L, and 2.9 +/- 0.5-1.2 +/- 0.1 mg/dl, respectively; p < 0.05). All five patients were successfully bridged to LVAS implantation, and none died of multiple organ failure caused by pre-existing cardiac failure. These results indicate that PCPS before LVAS implantation is useful in resuscitating impaired end organ function and improving the survival rate with LVAS implantation for end stage cardiac disease.

Adult↗
PubMed2004

Physiologic-insensitive left ventricular assist predisposes right-sided circulatory failure: a pilot simulation and validation study.

Right-sided circulatory failure (RSCF) is a serious complication in 15-30% of patients receiving a left ventricular assist device (LVAD). It is hypothesized that left ventricular support which lacks physiologic properties predisposes to RSCF. An integral computer simulation and experimental validation protocol was performed. The results suggest that with conventional insensitive left ventricular support right-sided circulatory function is compromised, which may form a substrate for the onset or progress of RSCF. Feedback control of the LVAD could provide a means to counter this problem. A control concept for the LVAD which aims to preserve right-sided circulatory function, while supporting peripheral perfusion, is proposed

Assisted Circulation↗