Biomedical subjects

R Hetzer

Publications and source records attributed to R Hetzer.

At least 451 records · Page 25Linked to original sources

PubMedDate not supplied

The relationship between the mitral annulus and left ventricular outflow tract.

Mitral annular inflexibility due to rigid prostheses (ring or valve) has long been considered to contribute to the mechanism of dynamic left ventricular outflow tract (LVOT) obstruction after mitral repair or replacement. In clarifying the geometric relationship between LVOT orifice and mitral valve annulus (MVA) in eight normal subjects, the authors have endeavored to show how that a rigid mitral prosthesis might obstruct the LVOT based on the assumption that any rigid prosthesis necessarily follows the motion of the posterior half of the MVA (MVApost) in the course of every heart beat. During systole, the relationship between the MVApost and the approximated plane of the LVOT orifice was constant. However, with the respect to the relationship between the LVOT orifice and the approximated plane of the MVApost (PI-MVApost), the intersection between the two shifted toward the apex during systole. Assuming the prosthesis is aligned on the MVApost with the same orientation as the PI-MvApost, this shift implies a reduction in the effective size of the LVOT orifice due to the prosthesis. The calculated obstruction rate was 24.9% (0 ms), 30.9% (100 ms), 35.5% (200 ms), and 45.4% (300 ms). These results indicate the importance of maintaining the flexibility of the MVA after mitral valve surgery.

Adult↗

PubMedDate not supplied

Complement activation in patients undergoing mechanical circulatory support.

Contact of blood with artificial surfaces activates pro-inflammatory responses and the complement cascade. This may have broad implications on the post implantation fate of patients needing mechanical circulatory support. Therefore, we investigated the course and prognostic value of complement factors C3a and C5a in 66 patients supported with pulsatile ventricular assist devices. All patients were in severe cardiogenic shock, i.e., catecholamine dependent and in the intensive care unit, before implementation of mechanical circulatory support. Isolated left ventricular support (Novacor [Oakland, CA] or Thermo Cardiosystems, Inc. [TCI; Woburn, MA]) was used in 28 patients, and biventricular support (Berlin Heart [Mediport, Berlin, Germany]) in 38 patients. Before initiation of mechanical circulatory support, no statistically significant differences in C3a or C5a between surviving and nonsurviving patients with left ventricular assist devices (LVADs) were found. Patients with biventricular assist devices (BVADs) had significantly higher C3a (804 +/- 364 ng/L) levels than patients with LVADs (536 +/- 204 ng/L, p = 0.02) before mechanical circulatory support. Only C5a, only in the BVAD group, was able to predict patients' post implantation course before implantation of a ventricular assist device (p = 0.02). Three weeks after initiation of mechanical circulatory support, complement factors remained increased in all groups. There was no difference, however, in complement activation between patients with LVADs and those with BVADs. Patients not reaching transplantation had significantly higher C3a levels at this point than those successfully supported (p = 0.007). The degree of complement activation mainly depends on the severity of cardiogenic shock before initiation of mechanical circulatory support, and not on the device used. Patients with extremely high levels of complement activation before implantation of the device could be saved with BVAD rather than LVAD support. Patients who continued to have highly elevated complement levels 3 weeks after initiation of mechanical circulatory support had unfavorable prognoses. Complement activation indicates the severity of cardiogenic shock before implementation of mechanical circulatory support and the degree of recovery from secondary organ dysfunction while on the device. It is fairly independent of the system used for mechanical circulatory support, and therefore can be applied to predict patients' post implantation course and outcome.

Adolescent↗

PubMedDate not supplied

Prevalence and persistence of heparin/platelet factor 4 antibodies in patients with heparin coated and noncoated ventricular assist devices.

Thromboembolism is a major complication in patients with ventricular assist devices (VAD). Anticoagulation with heparin, coumarin, and anti-platelet agents, particularly the development of biocompatible surfaces such as inner pseudo-endothelial layers or a coating with heparin, are intended to reduce these complications. However, the administration of heparin can lead to heparin induced thrombocytopenia type II (HIT II). Predominantly heparin/platelet factor 4 (HPF4) antibodies are responsible for the development of HIT II. The goal of the present investigation was to assess the prevalence of these antibodies in patients with heparin coated and noncoated VADs. Fifty-five patients were enrolled in the investigation. A heparin coated system was implanted in 30 patients, and a noncoated system was implanted in 25 patients. Antibodies were evaluated before, on days 7 and 14, and 3 months after implantation. Testing was performed with the Heparin/Platelet factor 4 enzyme-linked immunosorbent assay (ELISA) (Stago, France). In 40 of the 55 patients, the formation of HPF4 antibodies was observed (73%). In 35 of these patients (88%), HPF4 antibodies were present before surgery. There were no differences between the groups. In 11 patients (equal from both groups), the antibodies disappeared after termination of systemic heparinization. We conclude that in a rather high percentage of patients with VADs HPF4 antibodies are found. This finding may be explained by the repetitive and prolonged exposure of these patients to heparin. Immobilized heparin, as presently used in the carmeda coating, seems not to influence the formation and persistence of HPF4 antibodies. Further studies will have to prove whether HPF4 antibodies contribute to thromboembolic complications in these patients.

Adult↗

PubMedDate not supplied

Outcome of patients with ventricular assist devices and acute renal failure requiring renal replacement therapy.

The significance of acute renal failure (ARF) for patients treated with a ventricular assist device (VAD) is uncertain. There is little information on the outcome of patients who require renal replacement therapy during treatment with a VAD. A retrospective review was undertaken to evaluate the impact of renal failure requiring renal replacement therapy on such patients. Studied were 227 patients who were supplied with a VAD at the German Heart Institute Berlin. Fifty-five patients required renal replacement therapy during treatment with a VAD. These were compared with patients not needing renal replacement therapy (ARF and non-ARF groups). Significant differences for the end points of survival, heart transplantation, and discharge from hospital were observed in patients with ARF (p < 0.01). Survival was then analyzed according to indications for treatment with a VAD (bridge to transplantation or cardiac recovery after cardiotomy, transplantation, myocardial infarction, myocarditis, and endocarditis). Survival for bridge-to-transplantation patients was clearly influenced in a negative way by ARF (p < 0.01). For cardiac recovery patients, only a small difference in survival was observed (p = 0.05). We conclude that ARF is a negative predictor for bridge-to-transplantation patients. For cardiac recovery patients the impact of ARF on survival is marginally significant.

Acute Kidney Injury↗

PubMedDate not supplied

Effects of prosthetic valve placement on mitral annular dynamics and the left ventricular base.

Insertion of a rigid mitral prosthesis impairs the function of the mitral annulus and induces systolic narrowing of the left ventricular outflow tract (LVOT). To study this mechanism, we investigated dynamic changes in the left ventricular (LV) base, which consists of the mitral annulus and LVOT orifice. In seven patients with mechanical mitral valve prostheses and eight normal subjects, the image of the LV base was reconstructed three-dimensionally and its dynamic change during systole was studied. In the patients, the rigid prosthetic valve (=mitral annulus) tilted toward the left ventricle with a hinge point at the posterior mitral annulus during systole. The left ventricular base exhibited contraction, but the size of the prosthetic valve was constant. As a consequence, the prosthetic valve occupied more of the left ventricular base, which resulted in narrowing of the LVOT. In the normal subjects, the mitral annulus did not interfere with the region of the LVOT orifice during systole as the mitral annulus underwent both dorsiflexion and contraction. Thus, fixation of the mitral annulus induces an anti-physiologic motion of the annulus. Conscious preservation of annular flexibility in mitral valve surgery is important in avoiding potential dynamic LVOT obstruction.

Adult↗

PubMedDate not supplied

Transcranial detection of microembolic signals in patients with a novel nonpulsatile implantable LVAD.

Mechanical ventricular assist devices (VAD) have become an accepted therapy for the support of patients in severe heart failure. With the devices presently available, the incidence of thromboembolic complications is high. Since November 1998, we have used the DeBakey VAD (MicroMed, Inc., Woodlands, TX). To detect the effect of this VAD on the appearance of microthrombi or bubbles from cavitation, we measured Microembolic Signals (MES) with transcranial Doppler in patients after the implantation of the DeBakey VAD. Transcranial Doppler studies were performed with the MULTI-DOP X4 device with two 2 MHz probes (for the left and right middle cranial arteries [MCA]) in five patients preoperatively and during 10 weeks after VAD implantation. Both MCAs were monitored simultaneously for 60 minutes in 10 sessions in each patient. The detection and analysis of MES was performed in accordance with the technique and criteria described by the international consensus group. No MES were noted during the study period in four patients. In one patient with preoperatively noted MES the prevalence of MES postoperatively was 50%. The high speed rotating impeller of the DeBakey VAD did not produce any detectable microthrombi or bubbles from cavitation effects.

Adult↗

PubMedDate not supplied

Inflammatory response after implantation of a left ventricular assist device: comparison between the axial flow MicroMed DeBakey VAD and the pulsatile Novacor device.

The implantation of a ventricular assist device (VAD) is associated with a stimulation of the inflammatory system. We compared changes in the inflammatory response after implantation of a pulsatile Novacor left (L) VAD and the axial flow MicroMed DeBakey VAD. Six consecutive patients after implantation of a Novacor LVAD (NC) and six patients after implantation of a MicroMed DeBakey VAD (MD) were included in the investigation. Patients received LVADs for medically non treatable end-stage heart failure. Tumor necrosis factor alpha (TNF), C3a, C5a, interleukin 6 (IL-6), and neutrophil elastase were measured twice a week over a period of 3 months after implantation of the device. All tests were performed with an enzyme-linked immunosorbent assay. There was no significant difference in the clinical course of the two groups. All inflammatory parameters were elevated in both groups during the entire period of the investigation. There was no difference in TNF, polynuclear leukocyte elastase, or C3a levels between the two groups; however, IL-6 (NC: 23.6+/-37.6 pg/ml vs. MD: 63+/-114 pg/ml, p < 0.001) and C5a (NC: 708+/-352 microg/L vs. MD: 1,745+/-1,305 microg/L, p < 0.001) were increased significantly more in patients following implantation of the axial flow MicroMed DeBakey VAD. Compared with the pulsatile Novacor device, the implantation of the axial flow MicroMed DeBakey LVAD seems to be associated with an increased stimulation of one part of the inflammatory system. Further investigations are necessary for evaluation of the pathophysiologic mechanism and clinical implications of these findings.

Adult↗

PubMedDate not supplied

Autologous plasma and platelet sequestration at the beginning of cardiopulmonary bypass: a pilot investigation in five patients undergoing extended vascular surgery in deep hypothermia.

Platelet dysfunction and loss of procoagulants and platelets leads to impaired hemostasis after cardiopulmonary bypass (CPB). Preoperative platelet sequestration delays surgery, and the large volume shifts, necessary to harvest therapeutically effective components, may be associated with hemodynamic instability. We performed platelet and plasma sequestration after the initiation of CPB during the cooling period in patients undergoing surgery in deep hypothermic cardiac arrest. Five patients who underwent major vascular surgery in deep hypothermia were enrolled in this pilot study. Platelet and plasma sequestration was performed during cooling with the CATS cell saver using the plasma sequestration set. Before processing, 2 x 1,000 ml of blood were concentrated by means of hemofiltration to reduce dilution effects of CPB. The autologous platelet concentrates were rotated at 24 degrees C, and the plasma was stored at room temperature. The harvested plasma and platelets were re-transfused during modified ultrafiltration after CPB. Platelet count, 20 mmol/L ADP stimulated platelet aggregation, and fibrinogen levels were measured preoperatively in the harvested material and in patient blood before and after transfusion. A heparinase thromboelastogram (TEG) was performed preoperatively before and after re-transfusion. There was a significant increase in the ADP stimulated platelet aggregation, platelet count, fibrinogen level, and maximum amplitude of the TEG after re-transfusion of the harvested material. No patient needed transfusion of fresh frozen plasma or random donor platelet concentrates. No patient needed re-exploration due to hemorrhage. The data presented provide evidence that autologous plasma and platelet sequestration during CPB initiation is effective. The harvested material reveals a high platelet count and fibrinogen level and preserves functional integrity.

Aged↗

PubMedDate not supplied

Regional distribution of beta-adrenoceptors in the human heart: coexistence of functional beta 1- and beta 2-adrenoceptors in both atria and ventricles in severe congestive cardiomyopathy.

We evaluated the amount of beta 1- and beta 2-adrenoceptors in human right and left atrium as well as in right and left ventricular wall obtained from heart transplant recipients who suffered from end-stage congestive cardiomyopathy. The total number of myocardial beta-adrenoceptors was assessed with the nonsubtype selective beta-adrenoceptor radioligand (-)[125I]iodocyanopindolol (ICYP); concomitantly, the number of beta 1-adrenoceptors was determined with the selective beta 1-adrenoceptor radioligand (-)[3H]bisoprolol. The number of beta 2-adrenoceptors was calculated by subtracting (-)[3H]bisoprolol binding sites from ICYP binding sites. With this technique, a beta 1/beta 2-ratio of approximately 65/35% for both atria and of approximately 75/25% for both ventricles was found. Identical results were obtained when the beta 1/beta 2-ratio was calculated indirectly by nonlinear regression analysis of competition curves of the selective beta 1-adrenoceptor antagonist bisoprolol and the selective beta 2-adrenoceptor antagonist ICI 118,551 with ICYP binding. In addition, on atria and on ventricles, adenylate cyclase was activated by norepinephrine (presumably by beta 1- and beta 2-adrenoceptor stimulation) and by procaterol (by beta 2-adrenoceptor stimulation). It is concluded that in the human heart functional beta 1- and beta 2-adrenoceptors coexist on both atria and both ventricles. In end-stage congestive cardiomyopathy, there appears to be a selective down-regulation of cardiac beta 1-adrenoceptors, whereas beta 2-adrenoceptors are obviously not affected. This may explain the beneficial effects of beta 2-adrenoceptor agonists in severe heart failure.

Adenylyl Cyclases↗

PubMedDate not supplied

Fungal infections following heart transplantation.

Following heart transplantation (HTx), patients often suffer from mycoses due to the necessary immunosuppressive treatment to prevent rejection episodes. Oropharyngeal Candida infections which mostly occur after HTx under high-dose immunosuppressive therapy can be avoided and treated successfully by prophylactic medication to be started immediately after transplantation, either by using azoles (e.g. fluconazole) or amphotericin B suspension. Contrary to this, invasive aspergillosis, beginning in the upper respiratory tract and the lung and mostly followed by hematogenous dissemination into various organs, is always a serious disease with high mortality. To avoid this infection, specimens from the respiratory tract, serum and urine should be examined mycologically prior to HTx. After HTx, apart from prophylactic avoidance of exposure to airborne fungal spores, close mycological control is mandatory to detect colonizations by aspergilli early. Timely administration of amphotericin B and 5-flucytosine, i.e. as soon as invasive growth is suspected, enables curative treatment of the often lethal course of this disease, even under immunosuppressive therapy.

Aspergillosis↗

PubMedDate not supplied

Obstructive bronchial aspergillosis after heart transplantation.

Obstructive bronchial aspergillosis is a rarely observed consequence of Aspergillus infection. It occurs not only in patients with the acquired immunodeficiency syndrome (AIDS), but also after heart transplantation (HTx) if T cells are reduced markedly by the application of antithymocyte globulin (ATG) in addition to immunosuppression with corticosteroids. In contrast to invasive aspergillosis or Aspergillus tracheobronchitis, the course of this form of Aspergillus infection may not be accompanied by symptoms, because bronchial inflammation with pseudomembranes, ulcers or destruction of mucosa and intrapulmonary infiltrates are absent. To prevent invasive aspergillosis following HTx, intensive antifungal therapy is necessary in cases of bronchial obstructive aspergillosis, because this form of Aspergillus infection seems to represent a stage before recognizable invasive disease, as in other immunocompromised patients.

Aspergillosis↗

PubMedDate not supplied

Pressure controlled preparation of the saphenous vein with papaverine for aortocoronary venous bypass.

BACKGROUND AND METHODS: In 21 patients intraoperatively receiving coronary revascularization, segments of the saphenous vein were prepared for aortocoronary bypass. Postoperatively, the endothelial intima was subjected to electron microscopy. Venous segments in which an intraluminal mean pressure of 263 mmHg +/- 52 mmHg had been measured during preparation were compared with venous segments that had been explanted with the aid of a venous protection bulldog and with pharmacological treatment through papaverine. RESULTS: Those segments of high-pressure distension that had not been protected showed intimal damage with erythrocytes and thrombocytes. On the other hand, venous segments with low-pressure distension that had been protected in the described way during harvesting appeared similar to native veins. CONCLUSION: We conclude that during the preparation of the saphenous vein for aortocoronary bypass surgery, the application of papaverine and the use of the venous protection bulldog clamp is effective in preventing pressure damage during preparation of the vein.

Blood Platelets↗

PubMedDate not supplied

Histological findings after transmyocardial laser revascularization.

In recent time, it has become more and more probable that patients with severe diffuse coronary artery disease, who are not candidates for aortocoronary bypass surgery or percutaneous transluminal coronary angioplasty procedures, can benefit from transmyocardial laser revascularization (TMR). But the underlying principle of TMR still remains unclear. This study reports on a histological analysis of eight patients, in whom a total of 250 channels had been created, who died after TMR. The TMR channels were created by a CO2 laser surrounded by a zone of necrosis with an extent of about 500 microns. In the hearts of patients who died in the early postoperative period (1 to 7 days postoperative), almost all channels were closed by fibrin clots, erythrocytes, and macrophages. There were no obvious connections between the channels and the ventricular cavity. In specimens from patients, who died 2 or more weeks after the procedure, a granular tissue with high macrophage and monocyte activity was observable. Within this tissue, we observed a developing network of capillaries. Otherwise, the tissue filling the channels did not substantially differ from scar tissue. We failed to observe connections between the ventricular cavity and the new capillaries. Whether these vessels within the closed channels have any impact on myocardial perfusion remains unclear, but it seems unlikely that the clinical effects of TMR are based on the principle of the amphibian heart.

Aged↗

PubMedDate not supplied

Mitral valve reconstruction and mitral valve replacement for ischemic mitral insufficiency.

BACKGROUND: Patients with ischemic mitral incompetence have a high operative risk whether the valve is repaired or replaced. The advantage of repair over replacement is unclear in this group of patients. METHODS: Between April 1986 and December 1994, 232 patients underwent surgery for ischemic mitral valve insufficiency; mitral valve replacement was performed in 98 of them. Operative mortality was 13.3%. The actuarial survival rate after 5 years was 73.3%. The surgical risk in patients whose left ventricular ejection fraction (LVEF) was 10%-30% (operative mortality 50.0%) was higher than in those whose LVEF was greater than 30%. Valve reconstruction was performed in 102 patients. Operative mortality in this patient group was 14.7%. The surgical risk in patients whose LVEF was < or = 30% was higher (operative mortality 42.9%). RESULTS: The total actuarial survival rate of all patients was 64.4% after 5 years. Mortality during follow-up was higher in patients with residual mitral valve insufficiency greater than grade I after mitral valve reconstruction. Twenty-four patients with severely impaired left ventricular function underwent heart transplantation. Operative mortality in this group was 12.5%. Eight patients received left ventricular aneurysmectomy in addition to valve surgery, three of them died early. CONCLUSIONS: We conclude that patients with highly impaired left ventricular function and ischemic mitral insufficiency are at too great a risk for either valve reconstruction or replacement. Cardiac transplantation should be considered for this patient group. However, patients with ischemic mitral insufficiency and moderately impaired left ventricular function can undergo valve reconstruction or replacement with an acceptable prognosis. The goal of mitral valve reconstruction should be reducing mitral valve insufficiency to at least grade I. If this is not achieved, the prognosis after repair is worse than after valve replacement, therefore, the surgeon should replace the valve without delay.

Aged↗

PubMedDate not supplied

Mitral annular flexibility.

An analysis of three-dimensional movement of the mitral valve annulus (MVA) may address the question of geometrical change after mitral valve repair to preserve mitral annular function. Conventionally, annular contraction has been studied for this purpose. We investigated this geometrical change occurring in the anterior half of the MVA and discuss its clinical significance. Three-dimensional images of the MVA during systole were reconstructed from magnetic resonance images of eight normal subjects. The posterior half of the MVA exhibited translational motion. We assume that this portion, exhibiting translational motion as well as contraction, purely follows the motion of the left ventricular contraction. Compensating for the discrepancy between the motion of the aortic root and that of the posterior half of the MVA, the anterior half exhibited a flexible change in shape during systole, thus maintaining a sufficient left ventricular outflow tract (LVOT). The increase in the extent of displacement of the anterior MVA from the posterior half of the MVA during systole, which was 3.6 +/- 1.0 mm (mean +/- SD), indicates the annular flexibility. The preservation of annular flexibility may prevent LVOT obstruction. Further geometrical analysis of patients after mitral repair will clarify annular function as presented in this article.

Adult↗

PubMedDate not supplied

Predictors of survival 1 hour after implantation of an intra-aortic balloon pump in cardiac surgery.

From July 1996 to March 2000, 391 patients with intraoperative cardiac low-output syndrome who underwent surgery with heart-lung bypass and had an intra-aortic balloon pump (IABP) implanted were analyzed in a prospective study. Of these 391 patients, 153 (39%) were operated on in an emergency situation, and 238 (61%) patients had elective surgeries. The perioperative mortality was 34% (133 patients). Clinical parameters were analyzed 1 hour after IABP support began. Statistical multivariate analysis showed that patients with an adrenaline requirement higher than 0.5 microg/kg/min, a left atrial pressure higher than 15 mmHg, output of less than 100 mL/hour, and mixed venous saturation (SvQ2) of less than 60% had poor outcomes. Using this data, we developed an IABP score to predict survival early after IABP implantation in cardiac surgery. We conclude that the success or failure of perioperative IABP support can be predicted early after implantation of the balloon pump. In patients with low-output syndrome despite IABP support, implantation of a ventricular assist system should be considered.

Aged↗

PubMedDate not supplied

CT of heart transplant recipients: spectrum of disease.

The emergence of heart transplantation as the ultimate treatment for end-stage heart failure has been accompanied by new diagnostic challenges. Computed tomography (CT) has emerged as an important diagnostic tool in the evaluation of heart transplant recipients because many infectious, ischemic-hemorrhagic, and neoplastic complications are amenable to early detection with this modality. In the early postoperative period, CT is mostly indicated in the evaluation of infectious complications or cerebral symptoms. Later, CT is mostly performed for staging of infectious or neoplastic disease. Infectious complications include mediastinitis, soft-tissue inflammation, abscess formation, cerebral infarction, and aspergillosis. Complications related to ischemia or hemorrhage include allograft rejection and coronary allograft vasculopathy, the latter being the leading long-term cause of death in heart transplant recipients. CT is also indicated in malignant disease (eg, lymphoma, visceral carcinoma, skin tumors), which is the second most important long-term cause of death. Moreover, CT is helpful in identifying disease caused by immunosuppressive therapy (eg, leukoencephalopathy, osteoporosis, thoracic lipomatosis). CT has proved superior to both ultrasound and magnetic resonance imaging in the evaluation of heart transplant recipients. It has become the diagnostic modality of choice for many transplant-related complications and may help improve postoperative treatment of affected patients.

Diagnosis, Differential↗

PubMedDate not supplied

Effects of the Berlin Heart biventricular assist device on microvascular responses in pre-transplant patients.

Microcirculatory forearm cutaneous blood flow was monitored continuously and noninvasively by laser doppler flow-metry (LDF) in 15 patients treated with the Berlin Heart biventricular assist device system (BVAD) for end-stage heart failure under stable hemodynamic states (BVAD pts, n = 10) and norepinephrine therapy (BVAD nor pts, n = 5). Ten healthy human subjects served as controls (C). Cutaneous blood flow was measured before, during, and after external brachial artery occlusion to evaluate the post-occlusive reactive hyperemia (PORH) as a standardized response. To examine microvascular responses to macrohemodynamic changes, the cardiac output (CO) was decreased by a 20% reduction in BVAD pump rate. No significant differences in baseline LDF measurements (in millivolts) were observed among the three groups (C, 470.7 mV +/- 177.3; BVAD pts, 328.0 mV +/- 122.7; BVAD nor pts, 360.0 mV +/- 160.0). After cuff pressure release (1 min later), a significant (p < 0.004) three-fold to four-fold blood flow increase (PORH) occurred in each group (C, 1113.6 mV +/- 469.2; BVAD pts, 813.0 mV +/- 190.1; BVAD nor pts, 498.0 mV +/- 191.8). The difference in PORH between the BVAD pts and BVAD nor pts was significant (p < 0.01), and the time to peak PORH values was different (p < 0.05) among the three groups (C, 22.2 s +/- 10.7; BVAD pts, 11.3 s +/- 12.5; BVAD nor pts, 7.0 s +/- 5.8). A markedly delayed return to baseline occurred in the BVAD pts. The 20% reduction in BVAD pump rate decreased CO significantly (p < 0.05) and increased (p < 0.01) systemic vascular resistance (SVR).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗