Biomedical subjects
P Kühn
Publications and source records attributed to P Kühn.
[Muscle strength and functional results after surgical repair of Achilles tendon rupture with fibrin gluing].
Treatment of Achilles tendon rupture is discussed controversially. Some trauma centers prefer a conservative therapy. Because of the tendency to a higher rate of reruptures and worse functional results following conservative treatment, operation is the standard therapy of fresh ruptures of the Achilles tendon in Germany. Concerning the functional postoperative outcome, only few studies with uncomparable results were published. To evaluate the functional outcome after Achilles tendon ruptures treated by fibrin gluing, we realized reactive force measurements and motion analysis of 30 patients and 25 healthy test persons. We could observe significant limitations of active range of motion in the ankle joint and a significant deficiency of maximum- and rapid-force. Force deficiency was only detected by the sensitive technical examinations. In daily routine 26 of 30 patients had no limitations. The detected force- and motion-deficiencies were completely compensated. Therefore fibrin gluing of fresh ruptures of the Achilles tendon usually allows postoperatively the same leisure sports activity level as preoperatively. In competitive sporting athletes postoperative loss of performance must be expected.
[Invited comment on: Karl Friedrich Wenckebach: Clinical aspects and etiology of angina pectoris--therapeutic questions. From: Wien med Wschr 1924;74:735-739; Wien med Wschr 1924;74:907-912]].
Explore the source record for details and available documents.
[Secondary prevention following coronary intervention. Survey of 13 intervention centers in Austria].
Risk factor control has been shown to reduce the incidence of coronary events in patients with or without preceding infarction. Secondary prevention should therefore be borne in mind by every cardiologist. In order to test this concept and/or to promote secondary prevention in our country, the following survey was conducted by our working group for epidemiology and prevention. All interventional centres of the country (7 million inhabitants) were asked to report relevant data of 50 consecutive patients with PTCA in a structured questionnaire. Thirteen centres responded and we report the data of 650 patients. The mean proportion of women was 28%, the mean age 61.1 years and the mean stent rate 49.8%. The indications for PTCA varied widely: stable angina 10-74%, unstable angina 10-86%, primary PTCA 0-22%. The risk factor history was distributed as follows: diabetes 12-46% (mean 22.3%), hypertension 32-68% (mean 54.2%), current smoking 6-56% (mean 21.9%), and total cholesterol (TChol) > 200 mg/dl: 30-78% (mean 60.3%). Current lipid values were available for T chol. in 44-100% (mean 84.5%) and for LDL in 4-100% (mean 67.1%). Dietary counselling by a dietician was done in 4-100% of patients (mean 35.6%) Information concerning the hazards of smoking was given to 25-100% (mean 83.6%) of current smokers. Drug treatment at hospital discharge was as follows: 84-100% (mean 93.1%) received ASA, 24-74% (mean 49.8%) ticlopidine, 6-84% (mean 53.3%) nitrates, 34-82% (mean 60.2%) beta blockers, 10-70% (mean 39.5%) ACE inhibitors, 4-74% (mean 4 7.2%) lipid lowering drugs, 7-48% (mean 17.8%) calcium antagonists, 0-12% (mean 6.1%) digitalis and 0-28% (mean 13.6%) diuretics. Follow-up data were collected in 4 centres at 6 months post discharge and were available for 174 patients. Here we found an increase in the prescription of calcium antagonists, digitalis and statins. The following conclusions were drawn at a conference in which all centres participated: lipid values should be available for each patient at PTCA, dietary counselling should be initiated for every patient during hospitalisation (and continued by the family physician) and the national cardiac society should promote guidelines for the use of drugs in which the variation in use is too wide at present. It should be ensured that these guidelines are implemented not only in patients after AMI but also in those after PTCA.
[The "Inpatient Vaccination" Project in upper Austria. Technical report].
Explore the source record for details and available documents.
Images in cardiovascular medicine: complete heart block.
Explore the source record for details and available documents.
[Rational cardiologic diagnosis after cerebral ischemic event].
Stroke continues to be a serious socioeconomic problem in the industrialized countries. The three disease processes responsible for most ischemic cerebrovascular events (CVE) are large-vessel and small-vessel atherothrombotic disease and, in up to 20-30% of cases, cardiac embolism. Data from the literature show that life expectancy after CVE is mainly dependent on the coexistence of cardiac disease. It is the responsibility of the cardiologist to exclude or identify the source of cardiac embolism and to initiate adequate treatment for the prevention of recurrences, as well as to diagnose, and treat any concomitant cardiac disease which may be present. We propose a cost-effective algorithmic approach to help the cardiologist in the diagnosis and treatment of patients with transient ischemic attacks and ischemic stroke.
[Primary angioplasty in acute myocardial infarct].
We report our experience with primary angioplasty (PPTCA) in acute myocardial infarction performed without prior thrombolytic therapy. Between January 1991 and April 1993, 44 patients underwent PPTCA. Duration of symptoms was 163 +/ 106 min; age range of patients was 30 to 89 years (mean 60.6 +/- 13.5 years). Twelve patients presented with cardiogenic shock (27%), 17 patients (39%) had at least one relative contraindication for thrombolysis. Primary success rate was 98%. No stroke or major bleeding was observed. Reocclusion occurred in two patients, whereby this complication was silent in one of the cases. Significant residual stenosis remained in two additional patients. Three patients (7%) underwent elective bypass surgery (ACBG). Overall two-week mortality was 9%, and only 3% in the subgroup of patients without cardiogenic shock. Complete follow-up (FU) exceeding four months is now available in 36 patients (mean FU 13.7 +/- 7.3 months). During the FU period three patients had ACBG and five patients had PTCA. Thus, seven of 36 patients (19%) needed an additional procedure. Three patients had died, all of them were older than 70 years and initially presented with cardiogenic shock. Overall survival (in hospital and FU) was 84% (97% when patients with cardiogenic shock were excluded). Long-term survival (in hospital and FU) of the twelve patients initially presenting with cardiogenic shock was 50%. In conclusion, PPTCA is a promising therapeutic option in patients with acute myocardial infarction, especially when thrombolysis is contraindicated or when cardiogenic shock is present. It appears to be feasible even in centers with only one available catheterization unit.
Discrepancies between Doppler and catheter gradients across bileaflet aortic valve prostheses.
Explore the source record for details and available documents.
Effect of stenosis geometry on the Doppler-catheter gradient relation in vitro: a manifestation of pressure recovery.
OBJECTIVES: This study investigated the effect of stenosis geometry on the Doppler-catheter gradient relation. BACKGROUND: Although gradient estimation by Doppler ultrasound has been shown to be accurate in various clinical and in vitro settings, there have also been reports of substantial discrepancies between Doppler and catheter gradients. These conflicting results may be due to differences in geometry and hemodynamic characteristics of flow obstructions. METHODS: Stenoses of various geometry were simultaneously studied with continuous wave Doppler and catheter technique in a well controlled pulsatile flow model. RESULTS: Doppler and catheter gradients correlated very well regardless of stenosis geometry and site of distal catheter measurement (r = 0.98 to 0.99, SEE = 1.8 to 5.3 mm Hg). When the catheter was pulled back through the stenosis, the highest gradients were found in or close to the stenosis. When these catheter gradients were compared with Doppler gradients, the agreement between the two techniques was excellent regardless of stenosis geometry (slope 0.97; mean difference 0.6 +/- 2.0 mm Hg). However, when distal pressures were measured 10 cm downstream from the stenotic segment, the slope of the regression line, and therefore the agreement between Doppler and catheter gradients, differed for the different stenosis types (slopes from 0.98 to 1.69). In stenoses with abrupt narrowing and abrupt expansion, agreement was acceptable. Doppler gradients were only slightly greater than catheter gradients (mean difference 4.5 +/- 5.2 mm Hg). In stenoses with a gradually tapering inlet and outlet, the Doppler-catheter gradient relation was dependent on the outflow angle. Good agreement was found for an angle of 60 degrees (mean difference 0.6 +/- 1.8 mm Hg). In stenoses with a 40 degrees outflow angle, Doppler gradients exceeded the catheter gradients by 13% on average; for stenoses with a 20 degrees outflow angle, Doppler gradients exceeded catheter gradients by 46 +/- 11.4%, with differences as great as 65 mm Hg. These results were identical for stenoses gradually tapering outward to the distal tubing diameter and those with abrupt expansion after 2 cm of gradual expansion. The results were also not affected by changing the inflow angle from 20 degrees to 60 degrees. However, an abrupt narrowing instead of a tapering inlet significantly altered the Doppler-catheter gradient relation (p < 0.001); Doppler gradients exceeded the catheter gradients by 34 +/- 10% for this stenosis type. CONCLUSIONS: Doppler gradients accurately reflect the highest gradients across flow obstructions that occur in the vena contracta. However, these gradients may be significantly greater than catheter gradients that are measured farther downstream, as is usually the case in clinical catheterization studies. These discrepancies are due to pressure recovery. The magnitude of pressure recovery is highly dependent on the stenosis geometry, which therefore significantly affects the Doppler-catheter gradient relation. It is the outflow geometry that predominantly influences this relation, but the shape of the inlet may affect the results as well. Although pressure recovery occurs even in stenoses with abrupt narrowing and abrupt expansion, the phenomenon is most likely to become clinically relevant in stenoses with a gradually tapering inlet and outlet with an outflow angle < or = 20 degrees.
Effect of prosthetic valve malfunction on the Doppler-catheter gradient relation for bileaflet aortic valve prostheses.
BACKGROUND: Considerable discrepancies between Doppler and catheter gradients caused by localized gradients and pressure recovery have been reported for normal bileaflet aortic valve prostheses. METHODS AND RESULTS: To examine whether this Doppler-catheter gradient relation is affected by prosthetic valve malfunction, a 19-mm CarboMedics aortic valve was simultaneously studied with continuous-wave Doppler and catheter technique in normal function and in various states of malfunction ranging from slightly restricted opening to total occlusion of one leaflet. For each functional status, peak and mean gradients were measured at eight different flow rates (cardiac output, 2.0-6.0 L/min). Excellent correlation between Doppler and catheter gradients was found regardless of the valve function (r = 0.99, SEE = 1.0-3.3 mm Hg). However, the relation between Doppler and catheter gradient was highly dependent on the function of the valve as shown by a variation of slopes from 1.08 to 2.08. For the normally functioning valve (angle between flow axis and leaflet 5 degrees), peak and mean Doppler gradients were approximately twice the catheter gradients (slope, 2.08 and 2.03 for peak and mean gradients, respectively). Slightly restricted opening of one leaflet (22 degrees) significantly altered the Doppler-catheter gradient relation, and slopes decreased to 1.69 (p < 0.01) and 1.52 (p < 0.001) for peak and mean gradients, respectively. The differences between Doppler and catheter gradients significantly decreased with further restriction of valve opening, and slopes ranged from 1.25 to 1.41 for angles between 34 degrees and 52 degrees. When one leaflet was totally occluded, the slope finally dropped to 1.08 for both peak and mean gradients, and Doppler gradients were only slightly greater than catheter gradients. Gradients increased with malfunction of the valve caused by reduction of the effective orifice area. However, the increase of Doppler gradients was considerably smaller than the increase of simultaneous catheter gradients. CONCLUSIONS: The discrepancies between Doppler and catheter gradients that have been reported for normally functioning bileaflet aortic valve prostheses may be reduced or even disappear in patients with malfunctioning valves. Furthermore, the increase of Doppler gradients caused by malfunction of the valve may underestimate the true hemodynamic changes.
[The role of current diagnostic measures in hypertension].
The problems in diagnostic steps in the hypertensive patient can be grouped in 4 categories: the etiological evaluation concentrates recently especially on renovascular hypertension since. This disorder is getting more common with the ageing population and since diagnosis and treatment have been simplified; the detection of additional risk factors is important to guide individual drug selection; the detection of organ manifestations (e.g. LVH) may help in the therapeutic decision especially in borderline hypertensives; ambulatory blood pressure monitoring is becoming increasingly used despite the lack of standardized and generally accepted means to evaluate the recorded data.
[Acute management of myocardial infarct patients in Austria (cross-sectional study of 8 intensive care units)].
8 Austrian Intensive Care Units provided data from 6,317 cases (including 1,667 cases with acute myocardial infarction) admitted during 1990 and 1991 for a documentation system offered by the Austrian Heart Foundation. Significant differences were observed between the units concerning admission policies and the use of diagnostic methods. 71% of the AMI cases were first infarctions, 10% were Non-Q-infarcts. The median of the prehospital period varied between 2.5 and 6.5 hours. The evaluation of the admission mode showed that on average 42% of the AMI cases had contact to their G.P. before hospital admission, this figure varying, however, between 24 and 90% in different areas. It seems that this contact takes place to a much lower extent in big cities. On average G.P. contact before hospital admission in AMI resulted in doubling of the duration of the prehospital period. Thrombolytic treatment was applied in 24.7% of AMI cases with a variation between 13.9 and 48.4% in the different centers. It is suggested that regular use of this kind of quality control should offer means for optimizing the acute care of infarct patients on a regional and on a national level.
Importance of technical variables for quantitative measurements by color Doppler imaging.
Explore the source record for details and available documents.
[Anti-arrhythmia effectiveness of potassium-magnesium-aspartate infusion].
In 21 patients with ventricular arrhythmias we analysed the effect of an intravenous infusion of potassium-magnesium-aspartate. It could be demonstrated that the frequency of ventricular ectopic beats significantly declined 1 hour after starting the medication. The maximum effect occurred at the 6th and 7th hour and continued until the 10th hour after starting the medication.
[Significance of the anamnesis in women suspected to have coronary heart disease].
Pre-test probability for coronary artery disease can readily be determined using the patient's history, risk profile and resting ECG. The present study shows that this can be reliably done for both sexes. With pre-test probability of greater than 70% relevant coronary stenoses were found in both sexes in approximately 90%. With pre-test probability values of less than 60% this was only true in 20%. There seems to exist, however, a subgroup of female patients with rather atypical complaints but causing severe discomfort, showing normal coronary arteries it angiography. In these, subsequent myocardial metabolic studies and/or myocardial biopsy may reveal certain anomalies. Normal coronary arteries in women with chest pain therefore do not exclude any cardiac disorder. However the diagnoses to be expected from these sophisticated methods bear no consequences in terms of therapy. From a pragmatic point of view, therefore, it is suggested (for both sexes) to use pre-test probability in the selection for coronary angiography in order to detect organic coronary stenoses that can be managed by adequate treatment.
[Long-term electrocardiography (quality standards and guidelines for the documentation of findings].
Indications for a Holter-ECG-recording are dizzy-spells, syncopes, ischemic attacks, dyspnoea, ischemia of the myocardium, arrythmias after myocardial infarction and with different types of cardiomyopathies, the sick-sinus-syndrome and a-v-blocks; furthermore recording of cardiac situations and the effect of drugs. The report should mention the basic rhythm, ventricular and supraventricular arrhythmias as well as temporary blocks and pauses.
Quantitation of aortic regurgitation by colour coded cross-sectional Doppler echocardiography.
In 60 patients with aortic regurgitation, angiography and cross-sectional Doppler echocardiography have been compared in order to examine the reliability of the noninvasive method in quantitating aortic regurgitation. In a parasternal short-axis view just below the aortic valve, the ratio of the cross-sectional area of the jet divided by the cross-sectional area of the left ventricular outflow tract was determined. This measurement was possible in 50 patients (83%). Grossman's classification was used as the criterion for assessing the severity of aortic regurgitation by angiography. Values for the ratio of grade I ranged from 0.03 to 0.18, II 0.06 to 0.29, III 0.30 to 0.55, and IV 0.40 to 0.65. Assuming four Doppler grades (less than 0.15, 0.15-0.29, 0.30-0.44, greater than or equal to 0.45), we found complete agreement between the two methods in 42 patients (84%). In six cases there was underestimation, in two cases overestimation, by one grade only. Considering all cases, X2 analysis gave 96.6, P less than 0.00001, the contingency coefficient was 0.81. We conclude that, using this measurement, cross-sectional Doppler is a reliable method for the quantitative evaluation of aortic regurgitation.