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Biomedical subjects

T Forster

Publications and source records attributed to T Forster.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1991

[The significance of the dipyramidole echocardiography test in ischemic heart disease].

The diagnostic value of the dipyridamole echocardiography test was investigated in 46 patients who underwent coronary angiography due to suspected ischaemic heart disease. Twenty-two of 46 patients were found to have a narrowing of at least 70% one vessel. Twenty-four hour ECG monitoring was also performed on 19 patients on the day of the dipyridamole test. The sensitivity and specificity of the two-dimensional echocardiography test (new wall motion abnormality) were 72.7% and 62.5%. The ECG (V2-5-9) had a low sensitivity during the test (43.8%). Good agreement was found between the localization of the wall motion abnormalities and the site of anatomic narrowing in the ischaemic group. No significant ventricular arrhythmias were detected, and the sensitivity and specificity of ST-T changes were found to be 62.5% and 54.6% by means of Holter monitoring. The dipyridamole echocardiography test proved to be a suitable noninvasive method for the diagnosis of ischaemic heart disease and for the selection of patients for coronary angiography.

Coronary Angiography↗
PubMed1991

[Doppler echocardiography in the examination of normally functioning artificial mitral and aortic valves].

Patients with prosthetic valves were investigated by Doppler echocardiography in 902 cases between November 1987 and February 1990. The parameters of 209 of 344 mitral and 258 of 299 aortic prosthetic valves were evaluated. No significant correlation was found between the type of aortic or mitral prosthetic valves and the measured gradient. As concerns the size of the valve and the measured gradient, a close correlation for aortic valve replacement was detected. For a normally functioning mitral prosthetic valve, a maximum early diastolic velocity of less than 2 m/s (16 mm Hg gradient) and a pressure half-time of less than 130 ms (mitral valve area 1.8 cm2) were characteristic. In cases of aortic valve replacements, the maximum velocity was less than 3 m/s (36 mm Hg gradient), except for the small-diameter valves. More than 95% of the cases met these criteria. (Even if small-diameter valves were included, a maximum velocity of more than 3 m/s occurred only in 8.9%.) Doppler echocardiography is a suitable tool for detecting normal prosthetic valve function, while colour Doppler allows the optimal alignment of jet direction and Doppler beam.

Aortic Valve Insufficiency↗
PubMed1991

[Systemic thrombolysis in acute obstruction of an artificial valve].

Prosthetic valve thrombosis is a characteristic, but fortunately not frequent complication of surgical valve replacement. Its occurrence may lead to haemodynamic catastrophe. Three cases involving prosthetic valve thrombosis are presented. Two patients suffered from thrombosis after tricuspid valve replacement (St. Jude Medical), while the third occurred after mitral valve replacement (Sorin). In the acute phase, systemic thrombolysis was initiated (2 MU Streptokinase during 22-28 hours). The obstruction of one of the tricuspid valves and the mitral valve was eliminated. Lysis of the other tricuspid valve was not complete, but it helped the patient to survive the acute phase until reoperation. Embolization occurred in the inferior extremity after thrombolysis of the mitral prosthetic valve, but it was cured. Two-dimensional and Doppler echocardiography (conventional and colour-coded) played an important role in the diagnosis of the obstruction and in the follow-up of the effectivity of thrombolysis. Systemic thrombolysis may be a lifesaving procedure in acute prosthetic valve thrombosis. In spite of the potentially dangerous complications, it has to be attempted.

Adult↗
PubMed1991

[Judging the severity of regurgitation in acquired heart defects using color-coded Doppler echocardiography].

In the study, 139 valvular regurgitations of 120 patients (55 mitral and 84 aortic regurgitations) were investigated and compared by means of colour flow mapping and heart catheterization. During the echocardiographic examination, the length and width of the regurgitant jets were measured and the jet area was planimetered besides the subjective grades. The above parameters were correlated with the angiographic grades. Good agreement was found between the results of the two methods. As concerns the different parameters of the regurgitant jets in mitral regurgitation, the most severe (grade IV) category was easily distinguished from the others, while in aortic regurgitation all four categories were differentiated by colour flow mapping. These measurements indicated that colour-coded Doppler echocardiography is a suitable tool for detection of the severity of valvular regurgitations in a noninvasive way.

Aortic Valve Insufficiency↗
PubMed1990

The reproducibility of continuous wave Doppler measurements in the assessment of mitral stenosis or mitral prosthetic function: the relative contributions of heart rate, respiration, observer variability and their clinical relevance.

The reproducibility of continuous wave Doppler echocardiographic measurements of transmitral diastolic flow velocity were studied in terms of bias and random error in 40 patients with either mitral stenosis or a Björk-Shiley mitral valve prosthesis. Twenty-seven patients were in sinus rhythm; 13 patients had atrial fibrillation. Intra- and interobserver differences in bias were small for the Doppler parameters studied i.e. early peak velocity (0.6% vs 3.6%), mean diastolic velocity (1.1% vs 8.6%), mean temporal velocity (2.3% vs 14.5%) and pressure half-time (2.7% vs 4.8%). The overall random error of the measurements (in terms of twice the standard deviation) was estimated separately in patients in sinus rhythm and atrial fibrillation: early peak velocity 5.6% and 9.2%, respectively, mean diastolic velocity 9.4% and 22%, mean temporal velocity 8.6% and 19% and pressure half-time 34% and 46%. The relative contributions to the overall random error of observer variation, heart rate dependency and respiratory variation were also studied. Heart rate dependency was demonstrated for both the mean diastolic velocity and the pressure half-time. Respiratory variation was found in the early peak velocity. From the results of this study the number of measurements to reduce the random error of the final average could be determined. Our results indicate that for the measurements in which a respiratory effect is present it is advisable to average the measurements taken over complete respiratory cycles.

Blood Flow Velocity↗