PubMed Health⌕ Search

Biomedical subjects

B Heublein

Publications and source records attributed to B Heublein.

At least 19 recordsLinked to original sources
PubMed1992

Changes in cardiac beta 1- and beta 2-adrenoceptor densities after human cardiac transplantation: relation to transplant coronary vasculopathy and pretransplantation disease.

In 100 patients 12 to 60 months after cardiac transplantation, the influence of transplant coronary vasculopathy and of the pretransplantation disease (end-stage heart failure caused by coronary artery disease or dilated cardiomyopathy) on the beta-adrenergic receptor (AR) numbers and beta 1/beta 2-AR ratio of right ventricular biopsies was determined. Patients with coronary vasculopathy (CVP) after cardiac transplantation had lower absolute numbers of beta 1-AR compared with patients without CVP. Since patients with CVP had increased left ventricular (LV) end-diastolic pressure and LV muscle mass, it is suggested that decreased beta 1-AR may be the result of an altered hemodynamic situation of the transplanted heart after development of CVP. Patients with dilated cardiomyopathy (DCM) before cardiac transplantation showed a decrease in total beta-AR and of the beta 1/beta 2-AR ratio as a result of an increase in beta 2-AR and a decrease in beta 1-AR numbers. The decreased beta 1/beta 2-AR ratio in patients with previous DCM may indicate that the beta-AR system of the transplanted heart might be influenced (at least in part) by pathophysiologic factors that are characteristic of the pretransplantation disease ultimately leading to cardiac transplantation and persisting after cardiac transplantation.

Adult↗
PubMed1992

Systemic recombinant tissue plasminogen activator lysis for left atrial thrombus formation after single-lung retransplantation.

This report describes a recipient of single-lung transplantation surviving extraordinary complications: (1) early graft failure mandating retransplantation; (2) left atrial thrombus formation, which resolved by recombinant tissue plasminogen activator lysis; (3) and development of a "locked-in-syndrome." Possible underlying mechanisms are discussed.

Extracorporeal Membrane Oxygenation↗
PubMed1992

Decrease in beta 1- and increase in beta 2-adrenoceptors in long-term follow-up after orthotopic cardiac transplantation.

Total beta 1- and beta 2- subtype distribution were examined in right ventricular biopsies taken from 100 patients 1-60 months after orthotopic cardiac transplantation and from eight prospective transplant donor hearts serving as controls. The patients were classified into eight groups depending on the time after transplantation that the biopsies were taken: 1-3 (n = 15), 4-7 (n = 15), 8-11 (n = 6), 12 (n = 15), 24 (n = 15), 36 (n = 12), 48 (n = 12) and 60 months (n = 10). The non-selective beta-adrenoceptor antagonist (-)-[125I]-iodocyanopindolol (ICYP) was used as a radioligand to assess total beta-adrenoceptor density. The beta 1- and beta 2-subtype distribution was determined with a beta 1-adrenoceptor saturating concentration of the selective beta 1-adrenoceptor antagonist CGP 20712A (300 nmol/l). In transplant donor hearts the total beta-adrenoceptor density was found to be 70.8 +/- 7.1 fmol/mg protein including a beta 1:beta 2-adrenoceptor ratio of about 80:20%. Until 36 months after cardiac transplantation the total number of beta-adrenoceptors showed no significant change. A slight but insignificant decrease was observed after 48 (16.2%) and 60 (21.2%) months. In contrast, from 12 to 60 months after cardiac transplantation the beta 1:beta 2-adrenoceptor ratio was shifted significantly (66:33% to 61:39%) as compared with transplant donor hearts which was due to an increase in beta 2- and a decrease in beta 1-adrenoceptor number. Thus, the surgically denervated, transplanted human heart exhibits a beta 2-adrenoceptor up-regulation during long-term follow-up. It is suggested that this up-regulation of the beta 2-adrenoceptor subtype could be owing to an increased importance of circulating catecholamines in modulating positive chronotropic and inotropic effects.

Adult↗
PubMed1992

Enoximone, a post-operative inodilator in patients following mitral valve operation: a prospective and controlled study.

Inotropic support is often required for post-operative management of patients following mitral valve operation. The use of positive inotropes is limited by tolerance development and increase in myocardial oxygen demand. We have compared i.v. enoximone (E) (group E, n = 13), a recently developed phosphodiesterase (PDE) inhibitor, to the conventional i.v. therapeutics dopamine (D) and glyceroltrinitrate (G) in patients following mitral valve operation. The two groups were comparable in terms of physical and pre-operative haemodynamic data. Haemodynamic measurements including cardiac index (CI) determinations were recorded for the first 18 h post surgery in both groups. Group E received a bolus of 1 mg.kg-1 E followed by 4-20 micrograms.kg-1.min-1 (mean = 5 +/- 2 micrograms.kg-1.min-1) for 14 h according to therapeutic requirements, while group D received dopamine (4-10 micrograms.kg-1.min-1, mean = 3.8 +/- 1.9 micrograms.kg-1.min-1) and glyceroltrinitrate (0.5-5 micrograms.kg-1.min-1; mean = 4 +/- 2 micrograms.kg-1.min-1). Adrenaline was added if the MAP was below 60 mmHg or the CI was below 2.5 in both groups (range 50-500 ng.kg-1.min-1; mean E = 0.7 +/- 2 ng.kg-1.min-1; mean D = 2 +/- 2.8 ng.kg-1.min-1). Bolus injection of E resulted in a rise in CI from 2.6 to 3.21.min-1.m-2 (P less than 0.05) within 30 min, followed by a further rise to a maximum of 3.51.min-1.m-2 6 h post bolus. Termination of the E drip resulted in a drop of CI to baseline values (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Comparison of enoximone and piroximone in patients after mitral valve operation: a prospective and controlled clinical study.

Phosphodiesterase III (PDEII) inhibitors as so-called inodilators have previously proven a valuable alternative to positive inotropes in patients with cardiac insufficiency. In this study we compared patients receiving piroximone (P, n = 14, 0.5-mg/kg bolus in 30 min and then 3-6 micrograms/kg/min) with enoximone patients (E, n = 13, 1-mg/kg bolus and then 4-20 micrograms/kg/min) and with a third group (D, n = 14) receiving a combination of dopamine (4-10 micrograms/kg/min) and glyceroltrinitrate (0.5-5 micrograms/kg/min) for hemodynamic support. All three groups were comparable in terms of age, body surface area, and preoperative cardiac function [cardiac index (CI) less than or equal to 2.5 L/min/m2, LAP greater than 15 mm Hg]. Hemodynamic measurements (10) and Holter monitoring were performed until 18 h post MVR. In all groups, epinephrine was used for additional inotropic therapy if mean arterial pressure (MAP) was less than 60 mm Hg and/or CI was less than 2.5 L/min/m2. There was no early or late postoperative mortality in either group. Continuous support with epinephrine was necessary in 8 patients in group D, whereas initially 8 patients in group E and 6 patients in group P required epinephrine support. After PDE III inhibitor infusion, 2 patients in group E and 2 patients in group P remained epinephrine dependent (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Imaging of pulmonary artery and vein anastomoses by transesophageal echocardiography after lung transplantation.

BACKGROUND: In patients after isolated lung transplantation, the postoperative course may be complicated by dysfunction of the pulmonary artery and vein anastomoses. METHODS AND RESULTS: Pulmonary artery and vein anastomoses in 11 transplanted lungs (four left, four right, and three bilateral lungs) in 10 patients were studied 1 day to 11 months after operation by transesophageal echocardiography (TEE). All 14 pulmonary vein anastomoses, all seven right (100%) and five of seven (71%) left pulmonary artery anastomoses could be visualized by TEE. Thrombosis of a left pulmonary vein anastomosis could be identified by TEE and successfully treated by thrombolysis. TEE detected a significant stenosis in one right and one left pulmonary artery anastomosis; anastomoses dysfunction were confirmed by cardiac catheterization and pulmonary angiography and successfully treated by surgical correction in both cases. CONCLUSIONS: Function and morphology of pulmonary artery and vein anastomoses in patients after isolated lung transplantation can reliably be assessed by TEE. In patients with suspected dysfunction of an anastomosis, TEE may be considered the diagnostic technique of choice.

Adult↗
PubMed1992

[Modulation of vascular tone of normal and arteriosclerotic arteries by leukocytes].

Leukocytes, in particular mononuclear cells, play a central role in the pathogenesis of arteriosclerosis. The arteriosclerotic vessel wall is chemotactic for circulating leukocytes. Activated leukocytes are known to release a variety of vasoactive substances. Thus, activation of leukocytes in diseased arteries is not only an epiphenomenon of an inflammatory process, but instead may contribute to arteriosclerosis-associated complications such as vasoconstriction/vasospasm and thrombotic vessel occlusion. Influence of leukocytes on vascular tone appears to be complex and may be modulated by the presence of intact endothelium and additional blood constituents such as platelets. In vitro, mononuclear and polymorphonuclear leukocytes both relax and contract isolated arteries according to experimental conditions and leukocyte isolation protocols. In vivo, activation of leukocytes by chemotactic peptides f-met-leu-phe or complement C5a produces pronounced vasoconstriction. Mediators of these leukocyte-induced vascular responses are partially characterized and consist of nitric oxide (or EDRF-like factor), superoxide anions, thromboxane A2, peptidoleukotrienes, and an unknown contractile factor. In addition, leukocytes may indirectly modulate vascular tone by cleavage of angiotensin II from angiotensinogen or angiotensin I, and by inhibiting or stimulating platelet aggregation. Thus, leukocytes and their products may have several pathways to modulate vascular tone. Abnormal interactions between endothelium-platelet-leukocytes with vascular tone may play an important role in the pathogenesis of vascular complications in patients with coronary artery disease.

Animals↗
PubMed1991

Intraoperative echocardiography to detect and prevent tricuspid valve regurgitation after heart transplantation.

Tricuspid valve regurgitation (TVR) is frequently observed following orthotopic heart transplantation. The etiology of this phenomenon remains unclear. In a prospective study, we tried to identify pre-, intra- and postoperative factors possibly related to the occurrence of TVR in 15 patients (14 male, 1 female). Epicardial echocardiography was used during the transplant procedure and transthoracic echocardiography was performed at weekly intervals thereafter, TVR was graded semiquantitatively (grade 0-4). If TVR grade greater than 1 was detected after discontinuation of cardiopulmonary bypass, pericardial reduction plasty was performed (group R). If no or mild TVR (less than grade 1) was present, simple closure of the pericardium was carried out (control group). In group R the mean grade of TVR was 1.6 +/- 0.3 (SEM) before and 0.6 +/- 0.07 after pericardial closure (p less than 0.05). Following moderate elevation during the first 5 weeks, the degree of TVR reached levels slightly above the initial levels after 8 weeks. In the control group, a moderate increase of TVR developed during the first 8 weeks after surgery and remained at a significantly higher level than in group R (p less than 0.05). No preoperative risk factors for TVR, such as underlying disease or hemodynamic status of the recipients, was identified. Estimation of differences in heart volume between recipient and donor organs, by contrast, showed a significant discrepancy in group R but not in the controls. We therefore conclude that TVR in recipients of orthotopic heart transplants may be due to a size mismatch of donor heart and recipient pericardial cavity, resulting in distortion of the tricuspid valve ring.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Hyperacute rejection in heart allografts. Case studies.

Hyperacute rejection in orthotopic heart allografts is a rare event. In our material from a total collective of 524 heart-transplanted patients, we have observed two cases of hyperacute rejection, which are presented in this case report. Histopathologically, this entity is characterized above all by the following triad: pronounced edema, hemorrhages, and regressive changes up to necroses of myocytes. Besides the well-known risk factors, our report draws attention to two further factors possibly associated with an increased risk of hyperacute rejection: 1) repeated cardiac surgery prior to the transplantation, and 2) presence of identical viral genomes in recipient's and donor's heart.

Adult↗
PubMed1991

Acute haemodynamic profile of celiprolol in patients with coronary heart disease and hypertension: a double-blind comparison with metoprolol.

Celiprolol is a 'third generation' beta-blocking agent which is claimed to avoid problems associated with simpler beta-blockers, such as vasoconstriction, bronchoconstriction and myocardial depression. A double-blind randomized study was undertaken in 30 patients with coronary artery disease and hypertension to compare the haemodynamic effects of single intravenous doses of 0.15 mg kg-1 celiprolol (N = 16) and metoprolol (N = 14). Following celiprolol administration, the tendency was for myocardial function to improve or remain unchanged; left ventricular end-systolic volume and ejection fraction improved significantly (P less than 0.05). However, following metoprolol administration, the tendency was for myocardial function to deteriorate, with significant falls in cardiac output (P less than 0.05), ejection fraction (P less than 0.05) and velocity of circumferential shortening (P less than 0.01). There was a tendency for peripheral resistance to fall slightly with celiprolol but to rise markedly with metoprolol (pNS). Left ventricular pressure-volume loops showed improved performance with celiprolol and deterioration with metoprolol. Both drugs resulted in increases in coronary flow and myocardial oxygen consumption (P less than 0.05). Metoprolol, but not celiprolol, resulted in some deterioration in regional left ventricular wall motion (P less than 0.05). Celiprolol appears to be haemodynamically advantageous compared to metoprolol in patients with coronary artery disease and hypertension.

Adrenergic beta-Antagonists↗
PubMed1991

[Value of diagnostic procedures in heart failure].

Strategy for the diagnosis of heart insufficiency is directed to the accomplishment of distinct therapeutic aims. Main factors for diagnostic approaches are pathophysiology and progression of qualitatively and quantitatively different disturbances in cardiac performance. Anamnesis and clinical investigations are irremissible for the evaluation of congestive heart failure. For the detection of noncongestive cardiac insufficiency investigations during exercise are often necessary. Ventriculography ist the standard reference technique for measurement of the systolic and diastolic ventricular functions. For exercise and follow-up investigations non-invasive methods are widely used. Accepted methods are two dimensional and Doppler-echocardiography, quantitative radiocardiography with single-pass bolus technique, and radionuclid-ventriculography. We found a good correlation for the measurement of stroke volume when comparing impedance cardiography with uniplane ventriculography at rest. M-mode echocardiography did not yield sufficiently reliable volumetric data. The new imaging methods, positron emission tomography, magnetic resonance technique, and cine computed tomography are future tools for cardiac output measurements.

Coronary Disease↗