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Biomedical subjects

T Forster

Publications and source records attributed to T Forster.

At least 37 records · Page 2Linked to original sources
PubMed1994

Safety of dobutamine-atropine stress echocardiography in patients with suspected or proven coronary artery disease.

The purpose of this study was to establish the safety of high-dose dobutamine-atropine stress echocardiography in patients with suspected or proven coronary artery disease. Six hundred fifty consecutive examinations were completed. Mean age of patients was 61 years; 300 had a previous myocardial infarction. Heart rate increased from 73 to 129 beats/min during stress testing, blood pressure did not change significantly (from 140/81 to 150/80 mm Hg). Atropine was added to dobutamine in 239 patients when no ischemia was induced with dobutamine alone and the peak heart rate was < 85% of the theoretical maximal heart rate. Atropine was more frequently administered to patients taking beta blockers (77 vs 27%, p < 0.001). New wall motion abnormalities developed in 243 patients (37%). Significant or symptomatic cardiac tachyarrhythmias, or both, developed during 24 examinations: 1 patient developed ventricular fibrillation, 3 patients developed sustained ventricular tachycardia, 12 patients experienced nonsustained ventricular tachycardia (< 10 beats) and 8 patients had paroxysmal atrial fibrillation. Cardiac arrhythmias were more frequent in patients with a history of ventricular arrhythmias (ventricular tachycardia and fibrillation) (odds ratio 9.9, 2.0 to 45) or left ventricular dysfunction at rest (wall motion score > 1.12) (odds ratio 2.9, 1.1-7.6), but not associated with atropine addition. No death or myocardial infarction occurred. The full dose was not given to 13 patients despite absence of signs or markers of ischemia for limiting side effect, yielding an overall feasibility of the stress test of 98%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Comparative evaluation of dipyridamole and dobutamine 2-dimensional echocardiography in ischemic heart disease].

Dipyridamole and dobutamine stress were performed in the same 41 angiographically controlled patients. Both tests were followed by 2 dimensional-echocardiography. The dose of dipyridamole was 0.56 mg/kg/4 min. or 0.84 mg/kg over 10 min., while the dose of dobutamine was 10-20-30-40 and 40 micrograms/kg/min. over 3 min. each step. In addition, to reach the submaximal heart rate 0.25 mg/min Atropine was also injected for 4 minutes in 13 cases. One vessel disease was found in 15 cases, and 2 vessel disease was in 2 cases. The number of coronarography negative cases was 24. The sensitivity, specificity, positive and negative predictive values for both tests were 70%, 91%, 85% and 81%, respectively. False positive results were observed in 2 cases and false negative ones were found in 5 cases, mainly at left anterior descendent stenosis. There was a good agreement between the wall motion abnormality and the anatomic localization of stenoses. Both non-invasive tests are suitable for the diagnosis of ischaemic heart disease.

Adult↗
PubMed1994

Abnormal left ventricular early diastolic filling during dobutamine stress Doppler echocardiography is a sensitive indicator of significant coronary artery disease.

OBJECTIVES: This study was designed to assess changes in Doppler indexes of left ventricular ejection and filling in response to high dose (40 micrograms/kg body weight per min) dobutamine stress and their utility in detection of coronary artery disease compared with that of new wall motion abnormalities. METHODS: Ten patients with a low likelihood of coronary artery disease served as a control group, and 23 patients with documented single-vessel coronary artery disease underwent baseline and peak dobutamine echocardiographic and Doppler studies. RESULTS: In both groups dobutamine induced similar increases in heart rate and systolic blood pressure. During the test, 14 patients had new wall motion abnormalities, 13 had angina, and 7 had electrocardiographic ST segment changes. No markers of ischemia occurred in the control subjects. Dobutamine induced qualitatively similar changes from baseline to peak dobutamine stress in control subjects and patients in peak aortic velocity (46% vs. 42%, p = NS), average aortic acceleration (61% vs. 43%, p = 0.03) and systolic time-velocity integral (7% vs. 2%, p = NS). Dobutamine caused marked increases in control subjects and decreases in patients in peak early filling velocity (E) (33% vs. -22%, p < 0.0001) and average E acceleration (76% vs. -28%, p < 0.0001). The response of Doppler early filling indexes to dobutamine stress was abnormal in all patients. There was no overlap in the percent change from baseline to peak dobutamine stress between control subjects and patients for E and E acceleration. CONCLUSIONS: During dobutamine stress testing, an abnormal response of Doppler indexes of left ventricular early filling is a more sensitive marker of significant single-vessel coronary disease than are new wall motion abnormalities, and it is far superior to the response of Doppler ejection variables as a predictor of coronary artery disease.

Blood Flow Velocity↗
PubMed1994

Dobutamine-atropine stress echocardiography for assessment of perioperative and late cardiac risk in patients undergoing major vascular surgery.

OBJECTIVE: To determine the value of dobutamine-atropine stress echocardiography and clinical variables to predict perioperative and late cardiac events in patients scheduled for elective major non-cardiac vascular surgery. DESIGN: Blinded prospective study. PATIENTS: Patients (n = 187 mean age 69 yrs). MEASUREMENTS: Dobutamine-atropine stress test was performed preoperatively. Results were not used for clinical management. The clinical risk profile was evaluated by Detsky's score. RESULTS: Technically adequate images were obtained in 185/187 patients, one major complication occurred (ventricular fibrillation) and four tests were prematurely stopped due to side effects. Data from 181 patients were analysed. The stress test was positive (new or worsened wall motion abnormality) in 56/181 patients. Perioperative cardiac events were: five fatal myocardial infarctions, three non-fatal myocardial infarctions, nine unstable angina pectoris and one pulmonary edema. All patients with a cardiac event had a positive stress test (18/56). No event occurred in patients with a negative stress test. By multivariate analysis only a new wall motion abnormality during the stress test (odds ratio 45.0, 6-369) was a significant predictor of cardiac events. Patients (n = 154) were followed after operation for 16 +/- 9 months. Twenty-four cardiac events occurred in 21 patients: six fatal myocardial infarctions, three non-fatal myocardial infarctions, six unstable angina pectoris, three ventricular arrhythmias and six congestive heart failures. The stress echo was positive in 19/21 patients with late cardiac events. The cardiac events correlated by multivariate analysis with a history of myocardial infarction (odds ratio 9.6, 1.9-47.7) and new wall motion abnormalities (odds ratio 6.2, 1.5-25.1). CONCLUSION: Dobutamine-atropine stress echocardiography is a relatively safe and useful test to identify patients at risk of perioperative and late postoperative cardiac events.

Aged↗
PubMed1994

Atropine increases the accuracy of dobutamine stress echocardiography in patients taking beta-blockers.

Dobutamine-atropine stress echocardiography is used for the non-invasive diagnosis of coronary artery disease, but stress test results may be influenced by beta-blockers. The aim of this study was to assess if the addition of atropine can compensate for the presence of beta-blockers in dobutamine stress echocardiography. Twenty-six patients referred for evaluation of chest pain were studied twice, on and off metoprolol 100 mg b.i.d. (in random order sequence) with a wash-out period of at least 48 h. Dobutamine stress echocardiography was performed using up to 40 micrograms.kg-1.min-1, followed, if necessary, by the addition of atropine to achieve 85% of the age-predicted maximal heart rate, unless symptoms or markers of ischaemia appeared. Atropine was given to patients on beta-blockers more often [(22/26) vs (6/26)] than to those off beta-blockers (P < 0.001). Heart rate at every stage of the test was lower on beta-blockers. Chest pain occurred in patients on beta-blockers significantly less than in those off beta-blockers (8% vs 46%), and the addition of atropine made no significant difference (31% vs 46%). During dobutamine stress, new wall motion abnormalities occurred in three patients on beta-blockers (12%); this number increased to 15 after the addition of atropine (57%). New or worsened wall motion abnormalities occurred in 12 patients (46%) off beta-blockers with dobutamine alone and in 14 patients after adding atropine (53%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

HCV antibodies in Hungarian blood donations. Experiences collected by ELISA tests, immunoblot assays and polymerase chain reaction and protocols for donor management.

Routine screening of Hungarian blood donors for anti-HCV commenced in the second half of 1992. Before this, five available anti-HCV ELISA kits were compared in pilot studies. In the first series, 831 random donor samples were tested by one of the tests and the 12 (1.4%) reactives found were retested by the other four. Six of the reactives were positive in all ELISA. In the second series, 325 samples from donors with elevated transaminase levels were tested by all five kits. Forty-four were found to be reactive by one or more of the tests and 32 (10%) were positive in all five assays. Samples concordantly reactive in the ELISA were positive in second or third generation recombinant immunoblot assay (RIBA 2 or RIBA 3); those that gave discordant results were indeterminate or negative. Eleven concordantly reactive samples from the second series were HCV RNA positive by polymerase chain reaction (PCR). In the first period of screening with Abbott ELISA 2 a repeat-reactivity rate of 0.98% was observed in 171,106 samples tested. Reactives were retested for supplementary testing by Wellcozyme anti-HCV. Donors reactive in both tests and strongly reactive (ELISA ratio (ER) = optical density/cut off > or = 2.5) in either of them were permanently deferred. Those negative in the supplementary ELISA or weakly reactive (1.0 < or = ER < 2.5) in both tests were subjected to RIBA 2. On the basis of RIBA, positive donors were permanently deferred, indeterminates were excluded for 1 year and negatives were readmitted. In 1992, 1,347 supplementary tests were completed; 824 (61%) of the respective donors were permanently deferred, 218 (16%) were deferred for 1 year and 305 (23%) were readmitted.

Blood Donors↗
PubMed1994

[Stress echocardiography: 4 years of experience at the Thoraxcenter].

In this article, we report the experience on stress echocardiography at the Thoraxcenter of Erasmus University of Rotterdam in the years 1990-1994. Different types of stress have been used in conjunction with ultrasound techniques. The results have been compared with other non-invasive methods (exercise ECG testing, myocardial perfusion scintigraphy with single photon emission computed tomography) and with coronary arteriography. Both the diagnostic and prognostic value of stress echocardiography have been assessed in different clinical situations, as in patients with chest pain and suspected or proven coronary artery disease, patients referred for percutaneous transluminal coronary angioplasty, patients referred for major non cardiac vascular surgery. After this period of validation, stress echocardiography has now a definite role in the clinical decision making for the evaluation of myocardial ischemia. The assessment of viable myocardium, especially in patients with advanced left ventricular dysfunction, is one of the major topic currently under investigation. Practical aspects of the interpretation of the tests, costs and organization of the stress echo laboratory, indications and newest research applications are also discussed.

Angioplasty, Balloon, Coronary↗
PubMed1994

Potential and limitations of Tc-99m sestamibi scintigraphy for the diagnosis of myocardial viability.

Sestamibi is a Tc labeled radiotracer particularly suitable for myocardial perfusion studies, providing similar information as thallium scintigraphy for the diagnosis of coronary artery disease. In comparison with thallium, sestamibi has the advantage of improved imaging properties due to its higher gamma emission. This is particularly relevant when SPECT imaging is considered. The myocardial uptake of sestamibi is partially passively, related to the myocardial flow, and is also related to the metabolic cellular activity, as it is proportional to the electrochemical gradient generated at cell membrane level. While the role for sestamibi in diagnosing coronary artery disease is well accepted, it is still controversial for the assessment of myocardial viability. Clinical studies reported by others and results from our own institution will be described both in the setting of a recent myocardial infarction (myocardial stunning) and of longstanding left ventricular dysfunction (hibernating myocardium). The results concordantly suggest that sestamibi underestimates myocardial viability, compared to the accepted standards of thallium (rest-redistribution or stress-reinjection protocols), 18-F FDG PET and also in the prediction of left ventricular functional recovery after revascularisation. However, the data available at present are very limited, particularly after revascularisation. Furthermore, according to new promising results, the role of sestamibi in the setting of myocardial viability has potential for improvement, if the injection at rest will be performed during nitrates. It is also foreseen that the combined use of sestamibi perfusion/wall motion scan (first pass and/or gated perfusion studies) and the development of new softwares for attenuation correction might improve the results in the setting of myocardial viability.

Coronary Circulation↗
PubMed1993

Simultaneous dobutamine stress echocardiography and technetium-99m isonitrile single-photon emission computed tomography in patients with suspected coronary artery disease.

OBJECTIVES: The purpose of this study was to determine the relative value of dobutamine stress echocardiography and technetium-99m isonitrile single-photon emission computed tomography (mibi SPECT) in the detection of myocardial ischemia. BACKGROUND: Stress-induced new wall motion abnormalities and transient perfusion defects are both used for the diagnosis of myocardial ischemia. METHODS: One hundred five consecutive patients with either proved or suspected coronary artery disease, who were referred for perfusion scintigraphy, were studied by a combination of the two techniques. Both echocardiographic and mibi SPECT images were visually analyzed. Three patients were excluded from the final analysis because of unsatisfactory examinations: two with noninterpretable stress echocardiograms and one with noninterpretable mibi SPECT images. The response to stress was concordantly classified by both techniques in 68% of patients (kappa = 0.51). RESULTS: Dobutamine stress echocardiography revealed the presence of ischemia in 38 and mibi SPECT in 45 patients (overall agreement = 74%, kappa = 0.46). The agreement was higher in patients without previous myocardial infarction (84%, kappa = 0.62). When regional analysis was performed, concordance of stress echocardiography and mibi SPECT occurred in 84% of the 306 regions (kappa = 0.45). Regional agreement was also slightly higher in patients without previous infarction (88%, kappa = 0.50). In 21 patients without previous myocardial infarction who underwent coronary angiography, the overall sensitivity of dobutamine stress echocardiography and mibi SPECT for the diagnosis of coronary artery disease (diameter stenosis > 50%) was 75% and 83%, respectively, with a specificity of 89% (eight of nine patients) for both tests. CONCLUSIONS: Dobutamine stress echocardiography represents a reasonable alternative to dobutamine mibi SPECT for the functional assessment of patients with suspected myocardial ischemia and without previous myocardial infarction.

Adult↗
PubMed1993

Dobutamine stress--Doppler echocardiography before and after coronary angioplasty.

To determine if dobutamine-induced myocardial ischaemia causes abnormalities in Doppler parameters of left ventricular ejection and filling and to assess early effects of successful coronary angioplasty (PTCA) on these parameters, dobutamine stress echocardiography and Doppler studies were performed once in 11 normal volunteers and twice in 17 patients (within 1 day pre- and post-PTCA). Dobutamine induced wall motion abnormalities, ST changes and angina in 11, five and five patients, respectively, before and three, two and one patients, respectively, after PTCA. Doppler indices of both systolic and diastolic function were comparable at rest, before and after PTCA. Dobutamine induced similar increases in peak aortic velocity and average acceleration in healthy individuals (39% and 53%) and in patients with one-vessel disease both before (38% and 39%) and after PTCA (39% and 40%). In the three patients with multivessel disease, peak aortic velocity showed a blunted response (-0.3%) before PTCA but increased by 17% after PTCA, while acceleration decreased both before (12%) and after PTCA (14%). There were significant differences (P < 0.0001) between healthy individuals and pre-PTCA patients in the effect of dobutamine on peak early (E) filling velocity (+34% vs -19%), E-acceleration (+35% vs -26%), peak early to atrial filling velocity ratio (E/A) (-0.7% vs -37%) and diastolic time velocity integral (TVI) (+34% vs -22%). After PTCA, the response of Doppler diastolic indices improved during dobutamine, as shown by the increase in E and E-acceleration (+8%, +24%), respectively) and by the decline in the reduction of E/A and TVI (-17% and -10%, respectively). Thus, the response of Doppler diastolic parameters to dobutamine stress is a sensitive indicator of significant coronary disease and is superior to changes in ejection indices. Successful PTCA resulted in an improved diastolic filling response to dobutamine stress.

Adult↗
PubMed1993

Dobutamine stress echocardiography for assessment of perioperative cardiac risk in patients undergoing major vascular surgery.

BACKGROUND: The purpose of this study was to determine the predictive value of dobutamine stress echocardiography for perioperative cardiac events in patients scheduled for elective major noncardiac vascular surgery. METHODS AND RESULTS: Patients (n = 136; mean age, 68 years) unable to exercise underwent a dobutamine stress test before surgery (incremental dobutamine infusion [10-40 micrograms.kg-1.min-1] continued with atropine [0.25-1 mg i.v.] if necessary to achieve 85% of the age-predicted maximal heart rate without symptoms or signs of ischemia). The clinical risk profile was evaluated by Detsky's modification of Goldman's risk factor analysis. Echocardiographic images were evaluated by two observers blinded to the clinical data of the patients, and results of the test were not used for clinical decision making. Technically adequate images were obtained in 134 of 136 patients, one major complication occurred (ventricular fibrillation), and three tests were discontinued prematurely because of side effects. Finally, data from 131 patients were analyzed with univariate and multivariate methods. The dobutamine stress test was positive (new or worsened wall motion abnormality) in 35 of 131 patients. In the postoperative period, five patients died of myocardial infarction, nine patients had unstable angina, and one patient developed pulmonary edema. All patients with cardiac complications (15 patients) had a positive dobutamine stress test. No cardiac events occurred in patients with negative tests. Five patients with a technically inadequate or prematurely stopped test were operated on without complications. By multivariate analysis (logistic regression), only age > 70 years and new wall motion abnormalities during the dobutamine test were significant predictors of perioperative cardiac events. CONCLUSIONS: Dobutamine stress echocardiography is a feasible, safe, and useful method for identifying patients at high or low risk of perioperative cardiac events. The test yields additional information, beyond that provided by clinical variables, in patients who are scheduled for major noncardiac vascular surgery.

Adult↗
PubMed1993

[Anamnesis and myelography in the preoperative assessment of lumbar spinal stenosis. Results of a postoperative follow-up study].

Between 1987 and 1991, 33 patients with spinal stenosis of the lumbar spine were treated by decompression (33 patients) and posterior fusion (30 patients). Indication for decompression was based on case history and lumbar myelography with flexion/extension views. At follow-up 1-5.5 years later, 28 patients were happy with the results of the treatment and would be willing to be operated on again in a similar situation. Two other patients also presented objectively good results, but were dissatisfied for reasons not related to the operation. Our study shows that myelography and case history are adequate investigations for determination of the level of pathology and for making a decision about operative decompression in spinal stenosis of the lumbar spine. CT or MRI are only needed if the symptoms of the patient are not explained by the myelogram. Although MRI is advocated as the investigation of first choice for lumbar spinal stenosis, we still prefer the myelography, which is easier to interpret during the operation. Our study also shows that operative treatment of spinal stenosis is very rewarding, since 9 out of 10 patients will have good results. We usually combine decompression and fusion. Decompression alone is only performed in patients without any back pain and with stable motion segments after adequate decompression.

Adult↗
PubMed1992

Enhanced sensitivity for detection of coronary artery disease by addition of atropine to dobutamine stress echocardiography.

Patients undergoing dobutamine stress echocardiography often take beta antagonists which limit heart rate response and sensitivity in the test for detection of coronary artery disease. The aim of this study was to assess the effect of the addition of atropine to dobutamine stress echocardiography on clinical, electrocardiographic and echocardiographic outcomes. Dobutamine stress echocardiography was performed starting at and increasing every 3 minutes with 10 micrograms/kg/min to a maximum of 40 micrograms/kg/min (stage 4), which was continued for 6 minutes. In patients not achieving 85% predicted maximal exercise heart rate and in whom the test was not judged positive on echocardiographic or electrocardiographic criteria, atropine (0.25 mg intravenously, repeated up to a maximum of 1 mg if necessary) was added and dobutamine continued for up to a further 5 minutes, or until an adequate heart rate was achieved or the test was stopped because of chest pain or electrocardiographic changes. Of 80 consecutive patients undergoing dobutamine stress echocardiography within 2 weeks of coronary angiography, 49 required atropine (group A) and 31 required only dobutamine (group B). After dobutamine alone, heart rate (mean +/- SD) was higher in group B than in group A: 129 +/- 20 vs 90 +/- 18 beats/min, p less than 0.0001; but after the addition of atropine, heart rate in group A increased to 120 +/- 20 beats/min. Overall sensitivity for the detection of coronary disease was 70%, 95% confidence interval (CI) 55 to 83%; after the addition of atropine, sensitivity for group A was 65%, 95% CI 45 to 81%; in group B, sensitivity was 81%, 95% CI 54 to 96%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

The independent provider in home care. In search of a reasonable resolution.

The debate surrounding IP care has persisted for two decades--and intensifies as the demands for quality, accessible home care and client self-directed care grow. Policymakers must make every effort to thoroughly examine the issues related to IP care--from ambiguous employment status to competent care delivery--if a reasonable resolution is to be achieved.

California↗
PubMed1992

Does the measurement of left ventricular isovolumic relaxation time allow early prediction of cardiac allograft rejection?

In order to evaluate the value of isovolumic relaxation time measurement for the diagnosis of moderate acute rejection episodes in cardiac allograft recipients a comparison was made with the histological results from the endomyocardial biopsy. A total of 202 isovolumic relaxation time measurements from 26 patients were compared to the biopsy results. The technique used to record isovolumic relaxation time was dual M-mode echocardiography. In addition a combined phonoechocardiography was used for 54 isovolumic relaxation time measurements from 17 patients. A good correlation was found between these two methods. When the biopsy results were normal the isovolumic relaxation time was 71.4 +/- 15.1 ms. When moderate acute rejection episodes were present isovolumic relaxation time decreased to 50.2 +/- 21.2 ms (p < 0.001). In spite of the close correlation detected at group level, there was a large variability of the measurements without accompanying changes in the biopsy specimen. At the same time a significant overlap was found between the measurements taken during rejection and non-rejection periods making it impossible to use these methods for clinical decision making. We conclude that isovolumic relaxation time measured with these methods is not a sufficiently sensitive parameter for the diagnosis of moderate acute rejection episodes in the individual patient, and in our experience, it is not a substitute for endomyocardial biopsy and can not be applied for clinical decision making.

Adolescent↗
PubMed1991

[Diagnosis of femoral pseudoaneurysm and factors contributing to its incidence after heart catheterization].

Two-hundred patients who underwent heart catheterization between 30 November 1989 and 30 September 1990, were followed up to establish the frequency of the vascular complications (mainly femoral pseudoaneurysm) of the procedure. Factors were evaluated which may promote the occurrence of femoral pseudoaneurysms. This complication was diagnosed in 6 cases. Two-dimensional and Doppler echocardiography (conventional and colour-coded) played an important role in the diagnosis. Systemic hypertension, anticoagulant therapy, obesity and technical difficulties (multiple punctures and catheter guidance problems) proved to be factors promoting femoral pseudoaneurysms. Serial echocardiograms revealed a tendency to spontaneous healing even in cases of relatively large pseudoaneurysms.

Aneurysm↗