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Biomedical subjects

B Hesse

Publications and source records attributed to B Hesse.

At least 37 records · Page 2Linked to original sources
PubMed1999

Human bronchial artery blood flow after lung Tx with direct bronchial artery revascularization.

The inaccuracy of measuring human bronchial artery blood flow has previously been considerable. En bloc double-lung transplantation with bronchial artery revascularization (BAR) using a single conduit offers the unique opportunity of direct measurement of the total bronchial artery blood flow. In eight en bloc double-lung-transplanted patients with complete BAR, the basal blood flow was measured by using a 0.014-in. Doppler guide wire and arteriography. The average peak velocity in the conduit was 12-73 cm/s [+/-2.1 (SD) cm/s], and the conduit diameter was 1.7-3.1 mm [+/-0.10 (SD) mm], giving individual basal flow values between 19 and 67 ml/min [+/-5 (SD) ml/min], or 0.2-1.9% of estimated cardiac output. In three patients basal measurements were followed by injection of nitroglycerin and verapamil into the conduit. This increased the bronchial artery flow to 121-262% of basal values (31-89 ml/min). The measured values appear more physiologically plausible than previous bronchial artery blood flow measurements in humans.

Angiography↗
PubMed1999

Bronchial artery perfusion scintigraphy to assess bronchial artery blood flow after lung transplantation.

UNLABELLED: The bronchial arterial system is inevitably interrupted in transplanted lungs when removing the organs from the donor, but it can be reestablished by direct bronchial artery revascularization (BAR) during implantation. The purpose of this study was to visualize and quantify the distribution of bronchial artery perfusion after en bloc double lung transplantation with BAR, by injecting radiolabeled macroaggregated albumin directly into the bronchial artery system. METHODS: BAR was performed using the internal mammary artery as conduit. Patients were imaged 1 mo (n = 13) or 2 y (n = 9) after en bloc double lung transplantation with BAR. Immediately after bronchial arteriography, 100 MBq macroaggregated albumin (45,000 particles) were injected through the arteriographic catheter. Gamma camera studies were then acquired in the anterior position. At the end of imaging, with the patient remaining in exactly the same position, 81mKr-ventilation scintigraphy or conventional intravenous pulmonary perfusion scintigraphy or both were performed. Images were evaluated by visual analysis, and a semiquantitative assessment of the bronchial arterial supply to the peripheral parts of the lungs was obtained with conventional pulmonary scintigraphy. RESULTS: The bronchial artery scintigraphic images showed that the major part of the bronchial arterial flow supplied central thoracic structures, but bronchial artery perfusion could also be demonstrated in the peripheral parts of the lungs when compared with conventional pulmonary scintigraphy. There were no differences between scintigrams obtained from patients studied 1 mo and 2 y post-transplantation. CONCLUSION: Total distribution of bronchial artery supply to the human lung has been visualized in lung transplant patients. This study demonstrates that this nutritive flow reaches even the most peripheral parts of the lungs and is present 1 mo as well as 2 y after lung transplantation. The results suggest that bronchial artery revascularization may be of significance for the long-term status of the lung transplant.

Adult↗
PubMed1998

[Risk factors for the development of asthma in children and adolescents. Results of a longitudinal study].

To investigate risk factors for the development of asthma, a population sample of children and adolescents, aged 7 to 17 yrs at enrollment, were studied twice, with a six year interval; complete data was available for 408 subjects (199 males). Obtained case history was used to assess the presence of asthma; pulmonary function, skin prick test reactivity, total serum IgE and bronchial responsiveness to inhaled histamine (BHR) were measured using standard techniques. The 12-month period prevalence of asthma increased significantly from the first to the second examination in both males (p < 0.001) and females (p < 0.001), whereas the number of subjects with a positive histamine challenge test declined in both sexes. The prevalence of a positive skin prick test was higher at the second examination (26% and 44%, respectively, p < 0.001); the proportion of subjects with a positive skin reaction to house dust mite (HDMpos) increased from 14% to 26%. Confining the analysis to subjects without a history of asthma at the first examination showed that asymptomatic BHR (Odds Ratio [OR] 3.8 [95% Confidence Interval (CI) 2.5-5.1], p = 0.0002), HDMpos (OR 2.6 [CI 1.9-3.3], p = 0.005), a history of wheezy bronchitis before the age of two yrs (OR 3.8 [CI 2.4-5.2], p = 0.006) and a history of rhinitis and/or eczema (OR 2.8 [CI 1.7-3.9], p = 0.007) at first examination were associated with an increased risk for development of symptomatic asthma at some point between the two examinations. No significant relationship could be demonstrated between smoking (passive or active) and the risk for development of asthmatic symptoms. In conclusion, this longitudinal population study showed an increase in the 12-month period prevalence of asthma with sensitization to HDM and asymptomatic BHR as important risk factors for development of asthma.

Adolescent↗
PubMed1998

Continuous monitoring of global left ventricular ejection fraction during percutaneous transluminal coronary angioplasty.

Continuous monitoring of left ventricular (LV) function during percutaneous transluminal coronary angioplasty (PTCA) was performed in 40 patients (53 +/- 2 years) with a miniature, nuclear detector system after labeling the patients' red blood cells with technetium-99m. Balloon dilation (113 seconds, range 60 to 240) induced on average a 0.12 ejection fraction (EF) unit (19%) decrease in the LVEF, which was explained by a 34% increase in end-systolic counts. Balloon dilation of the left anterior descending artery (n = 23) produced a decrease in the LVEF of 0.17 +/- 0.13 EF units compared with the decrease of 0.06 +/- 0.07 EF units in patients undergoing dilation of the left circumflex artery (n = 9) and 0.05 +/- 0.04 EF units in patients treated for a stenosis of the right coronary artery (n = 8), (p = 0.02). Balloon deflation was associated with an immediate return to pre-PTCA levels. In 10 patients with 2 identical balloon occlusions, the second occlusion led to a significantly less decrease in the LVEF (0.41 +/- 0.14 vs 0.44 +/- 0.15) and electrocardiographic ST-segment deviation (88 +/- 54 microV vs 65 +/- 42 microV) than the first. We conclude that PTCA is associated with an abrupt transient decrease in the LVEF. The effect of balloon occlusion of the left anterior descending artery is more pronounced than balloon occlusion of the left circumflex and the right coronary arteries. Neither single nor multiple balloon occlusions were associated with post-PTCA global LV dysfunction, whereas the lesser degree of LV dysfunction and electrocardiographic signs of myocardial ischemia during the second of 2 identical balloon occlusions suggests that preconditioning can be induced during PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1998

Risk factors for reduced pulmonary function after malignant lymphoma in childhood.

The aim was to study pulmonary function after Hodgkin disease or non-Hodgkin Lymphoma in childhood and to evaluate if younger age at diagnosis and therapy is a risk factor for reduced pulmonary function. We studied a population-based sample of survivors of Hodgkin disease (n = 22) or non-Hodgkin lymphoma (n = 19) in childhood. Pulmonary function test results were compared with reference values for our laboratory, generated by adjusting published reference values fit 348 healthy never-smokers from a local population study. Data were analyses as standardised residuals, which are [observed minus predicted value] divided by the residual standard deviation of the reference equations. At a median of 11 years after diagnosis (range 2 to 24), the participants had significantly reduced lung volumes and transfer factor, unrelated to the few pulmonary symptoms. On average, the total lung capacity was reduced to -0.9 standardised residual and the transfer factor was reduced to -1.3 standardised residual. Young age at therapy seemed to be a risk factor for reduced lung function, especially when treatment included thoracic irradiation. No significant toxic synergism was observed between smoking and previous cancer therapy. Therapy without thoracic irradiation but with doxorubicin and cyclophosphamide was almost as toxic to lung function as therapy with thoracic irradiation but without doxorubicin and cyclophosphamide. In conclusion, lung volumes and transfer factor were reduced several years after childhood Hodgkin disease of non-Hodgkin lymphoma, with young age at therapy as a risk factor, especially when combined with thoracic irradiation.

Adolescent↗
PubMed1998

False-positive defects in technetium-99m sestamibi myocardial single-photon emission tomography in healthy athletes with left ventricular hypertrophy.

Exercise ECG and myocardial single-photon emission tomography (SPET) are fundamental in the non-invasive evaluation of patients suspected of having coronary artery disease (CAD). The purpose of the present study was to investigate the influence of physiological left ventricular hypertrophy (LVH) on myocardial sestamibi SPET in healthy young and old athletes. Eighteen young male elite athletes (ten rowers, five power/weight lifters and three triathletes) and 14 well-trained elderly rowers were studied. All underwent a bicycle test as part of a 2-day sestamibi SPET protocol. Attenuation correction was not performed. The studies were evaluated visually and quantitatively analysed by the CEqual program with its reference files and with a file from a local non-athletic age-matched population. Echocardiographic LVH was an inclusion criterion in the young athletes. Exercise ECG was normal in all subjects. In at least three of the young athletes a reversible defect was observed by visual analysis. On quantitative analysis one-third of the young athletes had "significant" (>10 pixels) defects compared with both the local reference base and the CEqual reference population. Nearly all defects were found in the anterior or inferior wall. The remaining subjects, including all old rowers, had normal SPET findings. Anterior and inferior wall defects are so common in healthy athletes with physiological LVH that the specificity of myocardial SPET, in contrast to exercise ECG, seems to be too low for evaluation of chest pain in this group. The mechanism of anterior and inferior defects may be related to hot spots (papillary muscles?) in the lateral wall. The specificity of SPET is maintained in athletes without LVH.

Adult↗
PubMed1998

Fluorodeoxyglucose uptake in dysfunctional myocardium subtended by an occluded coronary artery. Relation to dobutamine contractile reserve and Sestamibi uptake.

BACKGROUND: Myocardial segments with impaired function may have the potential for functional recovery. Augmented exogenous glucose uptake in relation to blood flow estimated by [2-18F]2-fluorodeoxyglucose (FDG) and positron emission tomography (PET) frequently indicates functional reversibility. The spectrum of FDG uptake levels in relation to Sestamibi uptake and dobutamine contraction reserve in areas with impaired function subtended by an occluded coronary artery has never been reported. METHODS AND RESULTS: Seventeen patients with stable angina pectoris and dysfunctional myocardium subtended by an occluded coronary artery were studied with FDG-PET, low-dose dobutamine echocardiography and Sestamibi-Single Photon Emission Computerized Tomography. In a 16 segment model dysfunctional myocardial segments showed a normally distributed FDG uptake ranging from 34% to 150% when normalized to peak segmental Sestamibi uptake. Low FDG uptake was associated with both lack of dobutamine induced contractile reserve and low Sestamibi uptake (in 73% of the segments) whereas high FDG uptake displayed both contractile reserve and Sestamibi uptake (57%). Segments with intermediate FDG uptake had either contractile reserve or a preserved Sestamibi uptake (62%). CONCLUSION: Dysfunctional myocardium subtended by an occluded coronary artery represents a continuum of metabolic states with a high degree of heterogeneity with regard to contractile reserve and Sestamibi uptake.

Adult↗
PubMed1998

Pulmonary function after treatment for acute lymphoblastic leukaemia in childhood.

The aim of this study was to examine pulmonary function after acute lymphoblastic leukaemia in childhood and identify risk factors for reduced pulmonary function. We studied a population-based cohort of 94 survivors of acute lymphoblastic leukaemia in childhood who were in first remission after treatment without spinal irradiation or bone marrow transplantation. Pulmonary function test results were compared with reference values for our laboratory, based on 348 healthy subjects who had never smoked from a local population study. A median of 8 years after cessation of therapy (range 1-18 years) the participants had a slight, subclinical, restrictive ventilatory insufficiency and reduced transfer factor and transfer coefficient. The changes in lung function were related to younger age at treatment and to more dose-intensive treatment protocols that specified more use of cranial irradiation and higher cumulative doses of anthracyclines, cytosine arabinoside and intravenous cyclophosphamide than previous protocols. We conclude that, 8 years after treatment without bone marrow transplantation or spinal irradiation, survivors of childhood acute lymphoblastic leukaemia in first remission were without pulmonary symptoms but had signs of slight restrictive pulmonary disease including reduced transfer factor. The increased dose intensity of many recent protocols for childhood acute lymphoblastic leukaemia may lead to increased late pulmonary toxicity.

Adolescent↗
PubMed1998

The diagnostic value of oesophageal radionuclide transit in patients admitted for but without acute myocardial infarction.

The use of radionuclide transit (RT) as a screening test for chest pain of oesophageal origin has been debated. The aim of this study was to determine the value of RT as a screening test for oesophageal disorders in comparison with oesophageal manometry in patients admitted with acute chest pain but without acute myocardial infarction (non-AMI patients), and to assess the frequency of oesophageal disease present in these patients. A total of 222 non-AMI patients entered the study. An extensive examination programme comprised noninvasive cardiac studies, pulmonary studies, a careful physical examination of the musculoskeletal system, and oesophago-gastric examinations including endoscopy, pH monitoring of the oesophagus and a Bernstein test. In 91% of the patients one or more diagnoses were obtained. Based on clinical and laboratory data a 'consensus' diagnosis was made. With manometry as the reference RT had a poor sensitivity (35%) but an acceptable specificity (82%). With the consensus diagnosis as the gold standard the sensitivities of both manometry and RT were poor (29%), whereas the specificity of RT, but not of manometry, was very high (97%). Gastrointestinal diagnoses were found in 57% of the patients. In conclusion, none of the applied oesophageal examinations are valuable as single screening tests. Both RT and manometry have low sensitivities. RT may be used as a cheap, noninvasive and rapid supplementary examination. When positive, it strongly supports further invasive studies of the oesophagus in non-AMI patients with unexplained chest pain.

Chest Pain↗
PubMed1998

Serial changes in atrial natriuretic peptide and endothelin-1 concentrations. Their relationships to the cardiac performance of patients hospitalized for acute myocardial infarction.

AIM: The study was designed to assess temporal changes in atrial natriuretic peptide (ANP) and endothelin-1 (ET) concentrations in patients hospitalized for acute myocardial infarction (AMI) and their relationships to cardiac performance determined by radionuclide ventriculography. PATIENTS AND METHODS: 20 patients with first AMI were studied. Blood samples were drawn within the first 4-18 h, after 18-24 h, and on days 2, 3 and 6. Plasma concentrations of ANP and ET were measured in blood samples taken simultaneously. Radionuclide ventriculography was performed on the day of discharge to determine left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume index, end-systolic volume index and left-ventricular stroke volume index. RESULTS: Median concentrations of ET decreased from 2.15 pmol/l on admission to 1.45 pmol/l at discharge (32%, p < 0.001). Median ANP rose from 29 to 79 pg/ml (172%, p < 0.001). The increment in ANP and the decrease in ET concentrations from admission to discharge was inversely correlated (r = -0.81, p < 0.005). ANP was inversely correlated to LVEF (r = -0.82, p < 0.001) and to the end-systolic volume index at discharge (r = -0.73, p < 0.003). CONCLUSION: Dynamic and inverse fluctuations in ET and ANP occur within the 1st week of AMI. The magnitude of endocrine activation in the ANP-ET system seems to reflect an impairment in the left-ventricular systolic performance.

Atrial Natriuretic Factor↗
PubMed1997

[The long-term prognosis of patients with acute chest pain of various origins].

A total of 204 patients with acute chest pain, but without myocardial infarction (non-AMI) were included. In 56 a definite diagnosis was obtained within 24-48 hours of admission. The remaining 148 patients underwent a comprehensive examination program. Ischaemic heart disease (IHD) was diagnosed in 64 patients, 81 had gastro-oesophageal disorders, 58 chest wall disorders, nine pericarditis, five pulmonary embolism, four pneumonia/pleuritis, three pulmonary cancer, two dissecting aortic aneurysm, one aortic stenosis and one herpes zoster. During 33 months of follow-up, 31 of the 64 patients with IHD had a cardiac event (cardiac deaths, non-fatal AMI, bypass surgery or PTCA) whereas only three events occurred among the 140 patients without IHD (p < 0.00001). However, the frequency of readmissions and of recurrent episodes of chest pain were similar in the three major diagnostic groups (NS). It is concluded that the high risk subset of a non-AMI population can be identified by means of non-invasive cardiac examination. The remainder who have other diagnoses are at low risk. However, the morbidity is high with frequent readmissions and recurrent episodes of chest pain, and the need for development of strategies with regard to diagnosis and treatment of these patients is emphasized.

Acute Disease↗
PubMed1997

Myocardial sestamibi single-photon emission tomography: variations in reference values with gender, age and rest versus stress?

Reference data files support the evaluation of myocardial perfusion single-photon emission tomography (SPET). The aim of this study was to create a large reference data base for technetium-99m sestamibi SPET, age and gender matched to the general patient population. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a likelihood of coronary artery disease of less than 5% underwent rest and maximal exercise 99mTc-sestamibi SPET with a 2-day protocol and 180 degrees elliptical rotation. The normalized activity values of 99mTc-sestamibi in the inferior wall differed significantly between men and women. Age variations were found for men in the anterior wall. Normalized activity values in all four walls were strikingly similar during rest and stress. Our results suggest that the use of reference files in 99mTc-sestamibi SPET requires a gender- and, for males, possibly an age-matched reference population. Different reference files at rest and during stress might not be necessary.

Adult↗
PubMed1997

Radionuclide tracers in the evaluation of resting myocardial ischaemia and viability.

Of all the tracer techniques currently available for the detection of myocardial viability, it is the classic pattern of fluorine-18 deoxyglucose-perfusion mismatch that is clearest from the conceptual point of view and consistently gives good predictive values. Measurements of absolute rates of glucose uptake depend on the much criticized lumped constant, never validated for myocardial ischaemia, and may provide little additional information or may even be confusing because of the bi-directional changes in glucose uptake in response to increasing ischaemia. Labelled nitroimidazole compounds are currently of interest because they are "ischaemia-avid" and because they can be imaged by a gamma camera. Nevertheless, much more work is required to show whether retention of nitroimidazole in ischaemic tissue may reflect viability.

Animals↗
PubMed1997

Technetium-99m sestamibi and tetrofosmin myocardial single-photon emission tomography: can we use the same reference data base?

The aim of this study was to compare technetium-99m labelled tetrofosmin and sestamibi myocardial perfusion single-photon emission tomography (SPET) with one common sestamibi reference file for bull's eye imaging, with quantitation of the extent and severity of perfusion defects. Twenty patients suspected or known to have coronary artery disease participated in the study. Patients first underwent routine sestamibi myocardial SPET over 2 days, receiving doses of 400-600 MBq at stress and 600-800 MBq at rest. Then within the same week a 1-day tetrofosmin myocardial SPET study was performed, with a dose of 300 MBq at stress, followed 2.5 h later by a dose of 750 MBq at rest. Bull's eye images were generated for visual evaluation. Black-out defects according to the Cequal software analysis were only recorded if they comprised more than 10 pixels in men and 20 in women. According to the Cequal program, extent score and severity scores were expressed as number of pixels and deviations below reference limits. Five patients had normal myocardial SPET imaging with both radiotracers, while 15 had reversible, irreversible or partially reversible defects. The concordance of the results was high. The only two significant differences were that one patient had a reversible defect which appeared to be located in different myocardial regions (LAD vs RCA), and another patient had a defect that was partially reversible with sestamibi but irreversible with tetrofosmin. The results showed very high correlation coefficients for the extent and severity scores (linear correlation coefficient values of 0.99 and 0.94, respectively). In conclusion, it appears that changing between sestamibi and tetrofosmin has little influence on the interpretation of bull's eye images from the data file of a common reference population using one of the tracers.

Coronary Disease↗
PubMed1997

The occurrence of false-positive technetium-99m sestamibi bull's eye defects in different reference databases. A study of an age- and gender-stratified healthy population.

Myocardial perfusion single-photon emission tomographic (SPET) imaging has been shown to be sensitive in the detection of coronary artery disease (CAD), whereas its specificity has been suboptimal. The aim of the present study was to study the frequency of abnormal bull's eye perfusion defects in a large age-stratified group of healthy subjects undergoing myocardial SPET assessed by comparison with two existing commercially available reference databases. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a less than 5% likelihood of CAD underwent rest and exercise technetium-99m sestamibi SPET. The false-positive response rate, defined as a significant reversible defect, was 12% when compared to the CEqual database and 29% when compared to the Cedars-Sinai database. With the CEqual program, rest defects occurred in 12% of the subjects. Defects occurred more often in women than in men, but the difference did not attain statistical significance. Significant defects were most frequent in the inferior wall and in women in the anterior wall as well. The distribution of defects was independent of age. Our results suggest that the specificity of 99mTc-sestamibi myocardial SPET using commercially available reference files is suboptimal. The risk of obtaining a false-positive test result in subjects undergoing 99mTc-sestamibi myocardial SPET with a very low likelihood of CAD was higher than anticipated. With both reference files false-positive test results were most frequently observed in the inferior wall. Our data suggest that commercial reference files for myocardial SPET need to be optimised, and should be used with caution. The use of attenuation correction may prove to be a major step forward.

Adult↗