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R Hetzer

Publications and source records attributed to R Hetzer.

At least 361 records · Page 20Linked to original sources
PubMed1989

[Postoperative results and follow-up of thoracic aortic diseases using magnetic resonance tomography].

Operations of the thoracic aorta for aneurysms, dissections, or congenital malformations may lead to early or late complications. Therefore, postoperative control for documentation of the surgical results, for exclusion of early changes and for comparison with later controls is mandatory. To demonstrate that magnetic resonance imaging (MRI), which we already had used with good results for preoperative studies is also able to detect postoperative abnormalities, we examined 30 patients with thoracic aortic disease (20 male, 10 female, mean age 53 +/- 13.7 years) with this diagnostic tool. There were 19 arteriosclerotic aneurysms, 10 dissections, and one aortic tumor. With MRI it was possible in all patients to visualize the results of the surgical treatment postoperatively. Early postoperative complications could be excluded, or demonstrated in one case of a retrograde aortic dissection or a hematopericardium. These pathological findings could also be shown by arterial digital subtraction angiography or echocardiography. Using MRI for follow-up of aortic dissections, the development of an aneurysm of the aortic root in a Marfan-patient could be detected. In all these patients, it was possible to differentiate true and false lumen and to detect the origin of major side branches. The diagnostic advantages of MRI, which we compared with other imaging methods, as echocardiography, computed tomography or angiography are that postoperative complications of thoracic aortic aneurysm surgery can be reliably detected and visualized in 3 different planes. Non-invasiveness, the omission of ionizing radiation and no risk of contrast media application underline that magnetical resonance imaging is an ideal method for follow-up after operation of the thoracic aorta.

Aortic Dissection↗
PubMed1989

Valve selection and choice in surgery of endocarditis.

The experience of the German Heart Center with valve selection and choice of size of prostheses for aortic root endocarditis is hereby reported. This experience includes 37 cases of aortic root endocarditis between 1986 and 1989. Mechanical, bioprosthetic, and homograft valves were used depending on the size, annular pathology, and general conditions related to the patient's medical history. Operative techniques are presented. Regardless of the type of valve replacement device, extensive annular destruction indicates a difficult and complex operation with long-term early and late results inferior to those in patients without annular abscess.

Adult↗
PubMed1989

Heart transplantation in Berlin.

Since July 1983, our group experience with heart transplantation as a routine procedure now includes 346 patients. Predominant diagnosis was dilated cardiomyopathy (64%). The age range was 3 months to 68 years (mean 44.3 years). Immunosuppression has followed several evolving protocols and now emphasizes preoperative administration of cyclosporine A and quadruple immunosuppression with additional azathioprine, cortisone medication, and early postoperative cytolytic prophylaxis with rabbit ATG. We have accepted donor organs up to 55 years without coronary angiography and with very satisfying functional and late results. The diagnosis of rejection by endomyocardial biopsy has been supplemented by routine use of telemetric intramyocardial electrogram monitoring and M-mode echocardiography. Routine use of these methods has distinctly increased diagnostic safety. Eleven children between the ages of 3 months and 18 years have been transplanted with a 72% overall survival rate. Four children younger than age 8 have been followed with noninvasive methods for rejection diagnosis exclusively. A bridge to transplantation program was initiated in July 1987; 31 patients were bridged, 18 of whom could be transplanted. Thirteen patients were discharged after a mean posttransplant period of 31 days. Future development issues will include extension of donor heart criteria, noninvasive diagnosis of rejection, and increasing experience with mechanical bridging.

Adolescent↗
PubMed1989

[Use of a noninvasive parameter of early diastolic ventricle function for the detection of graft rejection following heart transplantation].

Since changes in left ventricular early diastolic time intervals can be expected as one of the first detectable functional alterations indicating acute rejection in cardiac transplant patients, time-constant Te, a parameter derived from digitized M-mode echocardiogram, was proved as a marker of acute rejection. Echo results of 30 transplant patients (5-63 yrs) were correlated with myocardial biopsy results (48 rejection negative, 16 rejection positive) of the same day. In transplant patients the M-mode echo parameter Te is prolonged even in phases without rejection (79.0 +/- 12.5 ms vs 64.0 +/- 7.9 ms of healthy controls; p less than 0.0001). Te of transplant patients during rejection were significantly longer than Te of patients without rejection (97.8 +/- 17.9 ms vs 79.0 +/- 12.5 ms; p less than 0.0001). Individual courses demonstrate that rejection is associated with further prolongation of Te and that Te returns to individual basic value in response to treatment. So, Te may prove as a useful noninvasive marker of acute cardiac rejection.

Adolescent↗
PubMed1989

[Myocardial catecholamine content in heart failure--I: Regional distribution in explanted hearts. Comparison between dilated cardiomyopathy and coronary heart disease].

To quantify the myocardial catecholamine content in heart failure patients and to assess the regional distribution of catecholamines, we investigated norepinephrine and dopamine concentrations in explanted hearts from 34 patients in end-stage heart failure. 28 patients with cardiomyopathy were compared with six patients with coronary artery disease. In comparison with the right atria of a control group without heart failure, reduced myocardial norepinephrine contents (in pg/micrograms non-collagen protein (NCP] were found in all areas of the explanted hearts: controls: right atrium 17.6 +/- 6.6; cardiomyopathy: right atrium 7.1 +/- 7.9, right ventricle 4.4 +/- 2.7, septum 3.8 +/- 1.5, left ventricle 3.5 +/- 1.4. Coronary artery disease: right atrium 7.0 +/- 6.9, right ventricle 4.2 +/- 2.6, septum 3.6 +/- 1.4, left ventricle 3.4 +/- 1.4. Highest norepinephrine levels were measured in the right atrium. Right ventricle, septum, base and midventricular portion of the left ventricle had lower concentrations and were not different from each other. In contrast to reduced norepinephrine (NE) levels in all patients, dopamine (Dop) was inhomogenously elevated (only in a subgroup of 44%). Catecholamine contents in any two arbitrarily selected areas correlated significantly (NA: r = 0.53-0.77; Dop: r = 0.81-0.93, p less than 0.05 in all cases). The patients with heart failure due to dilated cardiomyopathy and to coronary artery disease did not differ in myocardial catecholamine levels or distribution. In end-stage heart failure a significant loss of myocardial norepinephrine independent from the underlying disease is found. It affects all areas of the hearts but does not equalize catecholamine content in ventricles and atria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Heart transplantation in childhood].

In nine patients between the ages of 3 months and 18 years with endstage heart failure, orthotopic heart transplantation was performed. Seven of these patients suffered from dilative cardiomyopathy. Additional diagnoses were tricuspid atresia in one case, and hypoplastic left-heart syndrome in another case. Seven of these children (77.7%) were catecholamine-dependent before the operation. The postoperative immunosuppressive treatment consisted of a combination therapy of cyclosporine A, azathioprine, and prednisolone, similar to the treatment in adults. Diagnosis of rejection was based on both invasive (endomyocardial biopsy) as well as noninvasive methods (intramyocardial electrogram, echocardiography, cytoimmunological monitoring). Out of nine transplanted children and adolescents, seven are presently alive and well after a mean follow-up period of 29 months. Two patients died of graft failure. One case with irreversible renal failure, secondary to chronic cyclosporine A toxicity required kidney transplantation 2 1/2 years following heart transplantation, this being the only significant late complication up to now. Our results indicate that heart transplantation allows for survival of seriously ill children and adolescents at a similar rate as that of older patient groups. Physical and social rehabilitation has been quite favorable and has been encouraging for further pursuit of this concept.

Adolescent↗
PubMed1989

Extended donor age in cardiac transplantation.

Approximately one third of brain-dead organ donors are above the age of 35 years. These donors have been used routinely for heart transplantation because the risks of compromised early graft function and potentially accelerated graft atherosclerosis remained nuclear. The increasing length of the waiting list and a 30% death rate of those on the waiting list for donor organs in our heart transplant program led to acceptance of donor hearts up to 54 years of age. Of a total number of 233 donor hearts, 74 were between 36 and 54 years old (group 2). These hearts were compared for early and chronic graft function with a group of 159 patients who received hearts from donors aged 1-35 years (group 1). All but three group 2 hearts were accepted without coronary angiography. Early postoperative graft function was sufficient in all 72 group 2 patients, whereas in group 1, early graft failure in nine (5.7%) patients led to death or required retransplantation. Forty-one patients in group 2 and 79 patients in group 1 were restudied at annual intervals between 1 and 4 years postoperatively by complete cardiac angiography. Mean late postoperative left and right ventricular ejection fractions were normal in both groups. Graft atherosclerosis was found in seven (8.9%) patients in group 1 and in four (9.8%) patients in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[The role of surgery in the treatment of acute myocardial infarct].

The surgeon's role in the treatment of acute myocardial infarcts is limited to selected cases in which emergency revascularization can be performed with reasonable expectation for salvage of an ischemic, however, still viable myocardium. This goal can be achieved under optimal logistic conditions. At present the result of emergency revascularization can not be predicted with certainty due to the lack of diagnostic methods which would allow for instantaneous differentiation between ischemic and necrotic myocardium. Surgical techniques are established for infarct sequelae such as ventricular rupture, papillary muscle necrosis, and ventricular septal defect, however, the outcome of emergency operations in these instances is primarily determined by the duration and intensity of preoperative circulatory failure. Cardiac transplantation with or without temporary mechanical support or replacement appears to be the future treatment of choice in acute irreversible congestive heart failure and global ventricular impairment following myocardial infarction.

Coronary Artery Bypass↗
PubMed1987

[Carnitine metabolism--changes in the end stage of dilated cardiomyopathy and ischemic heart muscle disease].

Biochemical analyses from endomyocardial biopsies indicate that cardiac energy metabolism is altered in patients with end-stage cardiac failure. Myocardial energy production is predominantly based on fatty acid oxidation. Carnitine, a naturally occurring compound, plays an essential role in fatty acid oxidation by carrying long-chain fatty acids into the mitochondrial matrix where they undergo beta-oxidation. In experimental animals, myocardial carnitine deficiency may cause cardiomyopathies which are reversible with carnitine substitution. Rare human diseases, as systemic carnitine deficiency, are associated with impaired cardiac function. We therefore investigated carnitine metabolism in patients with cardiac failure. Plasma and myocardial carnitine levels were measured in 55 patients undergoing cardiac transplantation because of end-stage cardiac failure based on dilated cardiomyopathy (DC, n = 30) or coronary artery disease (CAD, n = 22). Elevated plasma carnitine levels (controls: 49 +/- 12 microM; DC: 82 +/- 38 microM; p less than 0.001, CAD: 86.9 +/- 21.6 microM; p less than 0.05) were found in both patient groups (Fig. 1). Plasma carnitine did not correlate with creatinine (Fig. 2). Compared to controls, myocardial carnitine levels were significantly reduced: DC: 5.9 +/- 1.45 nmol/mg NCP; CAD: 5.84 +/- 1.84 nmol/mg NCP; controls: 15.6 +/- 5.4 nmol/mg NCP (Fig. 3). No correlation between myocardial and plasma levels was found (Fig. 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Dilated↗