PubMed Health⌕ Search

Biomedical subjects

M Hirschl

Publications and source records attributed to M Hirschl.

At least 19 recordsLinked to original sources
PubMed1997

The risk of recurrent venous thromboembolism in patients with and without factor V Leiden.

Thromboprophylaxis with oral anticoagulants up to six months is established in patients after a first venous thromboembolic event (VTE). The risk of recurrent VTE is still considerable thereafter, and it is uncertain whether some patients might benefit from extended anti-coagulation. We performed a prospective, multicenter trial (4 thrombosis centers) and evaluated in 380 patients with a first or recurrent VTE (patients with a deficiency of antithrombin, protein C, protein S or plasminogen; cancer; or an antiphospholipid antibody syndrome were excluded) the risk of recurrence after discontinuation of secondary thromboprophylaxis with oral anticoagulants. It was the aim of the study to evaluate whether patients, with factor V Leiden are at an increased risk of recurrent VTE. 112 (29.5%) patients were carriers of factor V Leiden (26.9% heterozygous, 2.6% homozygous). After a median observation time of 19.3 months the overall recurrence rate of VTE was 9.9%. Recurrent deep vein thrombosis and/or pulmonary embolism occurred in 26 of 268 patients without factor V Leiden (9.7%) and in 10 of 112 patients with factor V Leiden (8.9%). The probability of recurrent VTE two years after discontinuation of oral anticoagulants was 12.4% (95% CI 7.8-17) in patients without factor V Leiden and was 10.6% (95% CI 3.8-17.4) in carriers of the mutation. This difference was statistically not significant. Patients with factor V Leiden are not at a higher risk of recurrent VTE within two years after discontinuation of oral anticoagulants than patients without factor V Leiden. Balancing the risk of recurrent VTE and bleeding from oral anticoagulants, patients with factor V Leiden are not likely to benefit from oral anticoagulant therapy extended beyond six months.

Adult↗
PubMed1997

Prothrombin fragment F1+2 is not predictive for recurrent venous thromboembolism.

It would be important to estimate in advance the risk of recurrent thrombosis. Deficiencies of antithrombin, protein C or protein S, or resistance to activated protein C are associated with a biochemically detectable prethrombotic state. It is thus far unknown whether in patients with a history of thromboembolism but without a defined clotting abnormality a heightened coagulation activation is detectable. We investigated the value of prothrombin fragment F1+2 (F1+2) as a predictor of recurrent venous thromboembolism. Furthermore, we compared the F1+2 levels of thrombosis patients without a defined clotting defect to those of Factor V Leiden patients with a history of venous thrombosis and to those of healthy controls. 180 patients without a defined clotting abnormality and 73 patients with Factor V Leiden were prospectively followed after discontinuation of oral anticoagulants for venous thrombosis and F1+2 was measured at regular intervals. Recurrent venous thromboembolism occurred in 23 (9%) of the 253 patients. Before or at several time points after oral anticoagulants, no significant difference in F1+2 levels was found in patients with and without recurrent thrombosis. F1+2 levels at 3 weeks and prior to recurrence were not significantly different in both patient groups. Over a one-year observation period, F1+2 levels of both patients with and without Factor V Leiden were higher than those of the controls. No difference in F1+2 was seen between patients with and without Factor V Leiden. We conclude that monitoring of F1+2 is not suitable for identification of individuals at risk of recurrent venous thrombosis. Permanent hemostatic system activation is detectable both in patients with a defined abnormality of the clotting system and in patients in whom a particular defect has not (yet) been identified.

Adult↗
PubMed1997

Levels of prothrombin fragment F1+2 in patients with hyperhomocysteinemia and a history of venous thromboembolism.

Increased thrombin generation occurs in many individuals with inherited defects in the antithrombin or protein C anticoagulant pathways and is also seen in patients with thrombosis without a defined clotting abnormality. Hyperhomocysteinemia (H-HC) is an important risk factor of venous thromboembolism (VTE). We prospectively followed 48 patients with H-HC (median age 62 years, range 26-83; 18 males) and 183 patients (median age 50 years, range 18-85; 83 males) without H-HC for a period of up to one year. Prothrombin fragment F1+2 (F1+2) was determined in the patient's plasma as a measure of thrombin generation during and at several time points after discontinuation of secondary thromboprophylaxis with oral anticoagulants. While on anticoagulants, patients with H-HC had significantly higher F1+2 levels than patients without H-HC (mean 0.52 +/- 0.49 nmol/l, median 0.4, range 0.2-2.8, versus 0.36 +/- 0.2 nmol/l, median 0.3, range 0.1-2.1; p = 0.02). Three weeks and 3, 6, 9 and 12 months after discontinuation of oral anticoagulants, up to 20% of the patients with H-HC and 5 to 6% without H-HC had higher F1+2 levels than a corresponding age- and sex-matched control group. 16% of the patients with H-HC and 4% of the patients without H-HC had either F1+2 levels above the upper limit of normal controls at least at 2 occasions or (an) elevated F1+2 level(s) followed by recurrent VTE. No statistical significant difference in the F1+2 levels was seen between patients with and without H-HC. We conclude that a permanent hemostatic system activation is detectable in a proportion of patients with H-HC after discontinuation of oral anticoagulant therapy following VTE. Furthermore, secondary thromboprophylaxis with conventional doses of oral anticoagulants may not be sufficient to suppress hemostatic system activation in patients with H-HC.

Administration, Oral↗
PubMed1996

Five-year follow-up of patients after thromboendarterectomy of the internal carotid artery: Relevance of baroreceptor sensitivity.

BACKGROUND AND PURPOSE: In patients after myocardial infarction, baroreceptor sensitivity has been identified as a factor of prognostic relevance. This study was designed to assess the effects of an increased baroreceptor sensitivity in patients after surgery in the area of the internal carotid artery with respect to blood pressure variability, therapeutic interventions, and vascular events during a 5-year follow-up. METHODS: Receptor sensitivity before and immediately after carotid surgery was measured in 84 patients. Blood pressure variability, carotid artery status, and echocardiographic findings were assessed before and after surgery and at the end of follow-up. Vascular events as well as changes in blood pressure therapy during the follow-up period were evaluated. RESULTS: Significant negative correlations between an increase of baroreceptor sensitivity after surgery and the range of systolic (r=-.47; P<.001) and diastolic (r=-.33; P<.01) blood pressure were found for the immediate postoperative period. For the range of systolic blood pressure, this relation persisted (4.3 to 7 years after surgery) at the end of the observation period (r=-.38; P<.001). An inverse relation to the increase in baroreceptor function was also found for the average annual number of therapeutic interventions during follow-up (r=-.38; P<.001). Furthermore, the subgroup of patients without a postoperative increase of receptor sensitivity was characterized by a significantly higher risk of major vascular events (log-rank test, P<.018). CONCLUSIONS: Because an improvement of receptor sensitivity after carotid surgery is related to a long-lasting reduction of blood pressure levels and variability, baroreceptor function may be considered an indirect indicator for the later postoperative course.

Aged↗
PubMed1996

Initial prevalence and incidence of secondary Raynaud's phenomenon in patients with Raynaud's symptomatology.

OBJECTIVE: To establish the initial prevalence and incidence of secondary Raynaud's phenomenon (RP) in an outpatient population presenting with RP and assessment of the discriminating and predictive value of the variables of a diagnostic program. METHODS: 112 patients (average followup time 46 mo) were investigated prospectively. A screening program including anamnestic data, clinical examinations, noninvasive angiologic measurements, radiographic examinations, and laboratory chemistry was applied initially and repeated every 6 months. Patients with suspected secondary RP according to the screening underwent an extended diagnostic program. RESULTS: Based on the initial screening, 73 patients were classified as primary RP and 39 patients as suspected secondary RP. After examinations of the extended diagnostic program, 16 patients were diagnosed as secondary RP (initial prevalence 14.3%). During followup another 5 patients were diagnosed as secondary RP (annual incidence 1.4%). Using stepwise logistic regression, 7 screening variables were included in a model, leading to 96% correct classifications (sensitivity 86%, specificity 100%). Most of these variables were also suitable to predict the transition to secondary RP. An alternative classification based on a total symptoms score led to 94% correct classifications (sensitivity 86%, specificity 96%). CONCLUSION: The diagnostic program proved adequate and effective. Patients with RP and related arterial circulatory disorder showed a different clinical course than patients with an immunopathogenesis. A combination of several variables seems to be superior, with respect to the prediction and differentiation of secondary RP, to an approach based on single variables.

Adult↗
PubMed1995

Effects of macro- and microcirculatory functions on ceftriaxone concentrations in tissues of patients with stage IV peripheral arterial occlusive disease.

The objective of the study was to determine the ceftriaxone levels achievable within lesions (toe or forefoot area) in patients with septic gangrene and to investigate the relationship between macro- and microcirculatory parameters and antibiotic concentration. Fifteen patients with severe chronic peripheral occlusive disease received an intravenous injection of 2 g of ceftriaxone. Antibiotic levels in venous and capillary blood and in an exudative part of the lesion were measured. Macrocirculatory functions were assessed by Doppler sonography, plethysmography, and angiography; microcirculatory functions were assessed by quantitative capillaroscopy and fluorescence video microscopy. The mean antibiotic concentrations measured between 4 and 8 h after injection were 92 +/- 26 micrograms/ml in venous blood and 84 +/- 46 micrograms/ml in capillary blood. The concentration in tissue reached its maximum 4 h after injection; the average concentration at between 2 and 8 h was 95 +/- 55 micrograms/ml. Only dynamic capillary parameters showed significant (P < 0.01) correlations to antibiotic levels in tissue. Significantly (P < 0.01) higher levels in tissue were observed in patients with adequate microcirculatory functions (138 +/- 48 micrograms/ml) than in patients with poor microcirculatory function (51 +/- 26 micrograms/ml). Microcirculatory dysfunction appears to be the limiting factor for tissue antibiotic levels. However, even those patients with poor microcirculatory function showed tissue antibiotic levels that were above the MICs for the pathogens most frequently isolated from gangrenous lesions. Therefore, intravenous application was found to be adequate and additional measures such as intra-arterial therapy or Bier's occlusion are basically unnecessary. Our finding that microcirculatory function is the limiting factor for the tissue antibiotic concentration is corroborated by computations based on a three-compartment model.

Aged↗
PubMed1994

Cognitive brain function in non-demented patients with low-grade and high-grade carotid artery stenosis.

Atherosclerotic stenosis of the carotid arteries decreases cerebral flow volume and perfusion, and may result in brain dysfunction. We studied the relationship between the degree of carotid artery stenosis and cognitive brain function in non-demented patients. Cognitive brain function was assessed in 76 patients with carotid artery stenosis (38 patients with low-grade stenosis of 50% or less, and 38 patients with high-grade stenosis of 75% or more) by recording of cognitive P300 auditory evoked potentials and trailmaking test. Results were compared to 70 age-matched healthy subjects. The P300 peak latency was prolonged in patients with high-grade carotid artery stenosis as compared to patients with low-grade stenosis (403 vs. 371 ms, P < 0.01, vertex; 400 vs. 370 ms, P < 0.01, frontal; means). Analysis of variance revealed that the degree of carotid artery stenosis is an independent predictor of prolonged P300 peak latency (P = 0.0001). P300 amplitude (12 vs. 15 microV, vertex; 13 vs. 15 microV, frontal, NS) and trailmaking test (60 vs. 54 s; NS) tended to be worse in the high-grade stenosis group. There was no difference in cognitive brain function between patients with low-grade stenosis and age-matched healthy subjects. Confirmed on sensitive cognitive P300 measurements, we conclude that (a) cognitive brain function is impaired in non-demented patients with high-grade carotid artery stenosis but unaffected in low-grade stenosis; and (b) cognitive brain dysfunction is directly related to the degree of carotid artery stenosis.

Aged↗
PubMed1993

Normal AV node function in patients with sinus node dysfunction after cardiac transplantation.

Postoperative atrioventricular nodal (AVN) function was compared in 55 patients with normal and 50 patients with impaired sinus node (SN) function after cardiac transplantation (corrected SN recovery time > 520 msec or sinus arrest +/- escape rhythm). Fifty-two patients had fixed atrial pacing at cycle lengths between 600 and 430 msec, and 53 patients at cycle lengths from 600 to 300 msec between postoperative weeks 1 to 3. Relative (stimulus-R interval; AVNRRP) and effective AVN refractory period (AVNERP) were determined in 53 patients at a cycle length of 500 msec. Only one of 105 recipients had high degree AVN conduction disturbance characterized by a Wenckebach phenomenon at cycle length < 630 msec in the first postoperative week. Three patients with normal and two patients with impaired SN function had Wenckebach cycle lengths > 430 msec while the Wenckebach cycle lengths were < or = 430 msec in the remainder (p = NS). Resting PQ interval (146 +/- 18 vs 162 +/- 32; p = 0.09), Wenckebach cycle length (350 +/- 53 vs 362 +/- 50 msec), AVNRRP (356 +/- 38 vs 367 +/- 37 msec), and AVNERP (217 +/- 48 vs 244 +/- 49 msec) did not differ significantly between patients with normal and impaired SN function. AVN conduction did not deteriorate during 318 +/- 130 days of follow-up (PQ at follow-up 154 +/- 17 and 158 +/- 22 msec, patients with normal and impaired SN function, respectively). One DDD pacemaker was placed for AVN conduction disturbance while 22 pacemakers were implanted for SN deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Nuclear medicine studies of tissue concentration and hemodynamic effects of retrograde intravenous pressure infusions].

In 12 patients with trophic foot-lesions (diabetic feet) retrograde intravenous pressure infusions (150 ml) containing radioactive tracers (99m Tc, 99m Tc labelled human serum albumin) were carried out. With the veins emptied time-activity curves over the legs reflect tissue concentrations after release of the occlusion. Tissue-concentration is about 3 times higher than after intraarterial and 7 times higher than after intravenous injection of the same dose. The high count-rates which can be measured in the wound-secretion demonstrate the "rinsing effect" of the injected fluid. Hemodynamic investigations have been performed in a double blind study. 8 patients received buflomedil and 9 got placebo 3 times per week by retrograde intravenous pressure infusions. After 3 weeks there was an increase of the peak-flow on the lower leg (venous occlusion plethysmography), an increase of transcutaneous oxygen pressure and a fall of peak flow-time and of plasma-viscosity, both for buflomedil and for placebo (without statistical significance). Preliminary investigations after an arterial occlusion for 1 hour showed an increase of flow-values measured by venous occlusion plethysmography which reached a maximum after 4 to 5 days.

Aged↗
PubMed1993

Microcirculation of nailfold capillaries in chronic hemodialysis patients with and without diabetes mellitus.

The present study was intended to determine whether hemodialysis patients with arteriovenous fistula showed changes of microcirculation in the upper extremity. In addition, the study was to show whether such changes were correlated to the shunt parameters, such as the shunt flow volume, and whether the presence of diabetes mellitus had any additional influence. The study included 43 patients undergoing chronic hemodialysis; ten of the 43 patients were diabetics. Morphological and hemodynamic parameters of microcirculation were determined using quantitative capillaroscopy, flow volume in the brachial artery and shunt flow were measured by means of pulsed Doppler ultrasonography. While the morphological microcirculatory parameters did not show any differences between shunt arm and contralateral side, statistically significant differences were seen for resting blood cell velocity and for the time to peak capillary blood cell velocity after reactive hyperemia. For the latter a correlation to the shunt flow volume could also be demonstrated for nondiabetic patients. As expected, the time to peak blood cell velocity after reactive hyperemia was prolonged in both arms of patients with diabetes mellitus. Apparently, diabetes mellitus had a more pronounced effect on hemodynamic parameters than the Cimino shunt. This and the shunt flow will result in a Raynaud symptomatology. Other symptoms associated with chronic hemodialysis are mainly related to the duration of hemodialysis.

Arm↗
PubMed1992

Sinus node dysfunction after orthotopic cardiac transplantation: postoperative incidence and long-term implications.

We investigated incidence, normalization rates, and clinical significance of sinus node (SN) dysfunction after cardiac transplantation. Thirty-nine of 90 patients systematically evaluated presented with impaired SN function in the postoperative period. Of these, 22 normalized their SN function during follow-up while 17 remained impaired after 3 months. The proportion normalized was higher in patients with prolonged SN recovery time (11/16, 68.8%) and those reverting from escape rhythm to sinus rhythm until discharge (5/8, 62.5%) when compared to patients in escape rhythm throughout the postoperative period (5/11, 45.5%) or pacemaker dependence (1/4, 25%). There was no reliable postoperative predictor of normalization and necessity of long-term pacing. A postoperative heart rate consistently less than 70 beats/min (irrespective of the native rhythm) was significantly related to outcome (P = 0.01), but revealed unacceptable sensitivity (61.5%) and specificity (81%). After all, both patients with severe symptoms (near syncopes and syncope), were derived from this group. These two patients, who had been discharged in sinus rhythm, had late pacemakers implanted. An additional 17 patients had early pacemaker placement, only seven of which were constantly paced during follow-up. Given the low normalization rates, patients with postoperative escape rhythm are those most likely to benefit from pacemaker therapy over the long term. Even those in, or reverting back to, sinus rhythm until discharge may experience severe symptoms, particularly in the setting of a postoperative rate consistently less than 70 beats/min since this indicates a relatively lower probability of recovery.

Algorithms↗
PubMed1992

Bacterial flora in mal perforant and antimicrobial treatment with ceftriaxone.

The objectives of this pilot study were to identify the bacterial flora of neurotrophic ulcers, and to determine whether treatment with ceftriaxone improves the clinical picture. Twenty-five patients (15 male, 10 female, mean age 70 +/- 11 years) with mal perforant were treated with 2 g ceftriaxone once daily until the ulcer was healed, or for a period of 6 weeks. Biopsies were taken from the ulcer floor before and after therapy. Initially, the following bacteria were found, in order of frequency: Staphylococcus aureus, enterobacteria, coagulase-negative staphylococci, enterococci and streptococci as well as Pseudomonas aeruginosa. Under therapy with ceftriaxone, the lesions of 11 patients were healed; in 5 patients improvement > 50% was observed and in 4 patients improvement was < 50%. In 3 patients there was no change in the condition. Two patients had to stop treatment due to diarrhea. Asepsis was achieved in 5 patients despite persistence of the ulcer. The control group (25 patients without antibiotic therapy) showed the following results: healing in 6, improvement > 50% in 5, improvement < 50% in 10, and no change in 4. The results for the treatment group have to be compared with a historical control group since, for ethical reasons, the implementation of a double-blind study would not be feasible.

Aged↗
PubMed1992

Postoperative sinus node dysfunction in the transplanted heart. Impaired automaticity but normal refractoriness.

We describe the use of the extrastimulus technique to define the range of sinus node (SN) effective refractoriness (SNERP) in the denervated transplanted human heart. SNERP could be successfully determined in 18 of 28 patients corresponding to 25 of 43 SN studies and ranged from 210 to 360 ms at a basic pacing cycle length of 500 ms (95 percent confidence limits: 252.5 to 296.2 ms), which is shorter than reported in the innervated native heart. Sixteen data sets in 12 patients showed normal SN function and nine sets of measurements in seven patients showed abnormal SN function (corrected SN recovery time greater than 520 ms). While recovery time was profoundly abnormal (279.7 +/- 94 vs 7,284.8 +/- 10,454, p less than 0.001), the SNERP did not differ significantly between the groups (274.3 +/- 40 vs 286 +/- 42 ms at 500 ms, p = 0.5) and was normal at a range of 220 to 340 ms even in those patients with grossly impaired SN recovery (SNERP in patients with normal SN function: 210 to 360 ms at 500 ms). This study demonstrates that SN refractoriness in the transplanted human heart is shorter than previously reported in innervated controls and suggests that posttransplantation SN dysfunction is characterized by impaired automaticity rather than impaired refractoriness.

Adult↗
PubMed1991

Arterial baroreflex sensitivity and blood pressure variabilities before and after carotid surgery.

Carotid surgery is frequently associated with postoperative blood pressure alterations. The role of baroreceptors with regard to these alterations was assessed in 50 patients by determining the pre- and postoperative mechanoreceptor sensitivity after Valsalva maneuver and intravenous injections of angiotensin and nitroglycerine as described by Smyth, Sleight and Pickering. In addition, blood pressure was monitored perioperatively and renin and aldosterone levels were measured. In patients with arterial hypertension a postoperative increase of receptor reactivity can be seen necessitating a reduction of antihypertensive therapy in more than 50% of cases. In normotensive patients no uniform response can be observed. A possible explanation for this effect might be the local increase of pressure in the operated vascular segment. The postoperative reintegration of receptor areas which had been adjusted to a reduced pressure level might induce a more sensitive response than can be seen for the remaining receptors, which usually are less responsive in hypertensive patients.

Aged↗
PubMed1991

Outpatient percutaneous transluminal angioplasty: preconditions and results.

The present study considers whether percutaneous transluminal angioplasty (PTA) using a balloon catheter may also be performed on an outpatient basis. The prerequisites for the choice of an out-patient procedure were location of the flow obstruction above the knee joint, exclusive catheter recanalisation, absence of any complications during and after the intervention, radiological and vascular surgical standby, patient compliance and adequate social environment. In our 36 patients, 12 PTAs were performed in the pelvic region, 23 in the area of the femoral artery and one in the area of the popliteal artery. The primary success rate in the pelvic region was 100%, that in the femoropopliteal region 91.7%. The cumulative patency rate after an average follow-up period of 4 months was 89% (one early recurrence within 24 hours, 2 late recurrences after 3 and 5 months, respectively). In order to prevent early recurrence, thrombocyte aggregation inhibitors were given in combination with heparin at standard dosage. Two patients had to be hospitalized for monitoring after an aspiration embolectomy in the one case and a major haematoma in the other case. The advantages of a PTA intervention performed on an out-patient basis were the reduced time lag between diagnosis and therapy, full mobility of the patient and minimisation of hospitalization costs. Our results justify the choice of an outpatient schedule for the performance of balloon catheter recanalization in a carefully selected patient population.

Adult↗
PubMed1991

[Moenckeberg media sclerosis: clinical aspects in diabetic patients].

We assessed in 1662 consecutive diabetic patients systolic arm-ankle indexes by a Doppler ultrasonic method. In those patients with indexes greater than or equal to 1.3 directional Doppler sonometry and mercury strain gauge plethysmography were performed. In some instancies electronic oscillography, duplex sonography and vital microscopy were additionally done. In 4.45% of the patients functional findings of a mediasclerosis could be encountered. Location of arterial mediacalcinosis was documented by x-ray examinations. Sensitivity of none invasive methods was merely 100%, specificity ranged from 96% (Dopplersonometry) to 80% (Duplexsonometry). In 18.9% an occlusive arterial disease could additionally be found. Mediasclerosis preferentially was encountered in Type II diabetics of older age. In this group painful distal neuropathy in many instances existed mimicking claudication, retinopathy and nephropathy was as frequent as in other diabetics. Normal or elevated Doppler indexes did not exclude occlusive arterial disease whereas diabetics with mediasclerosis and ulcero-gangreneous lesions or amputations in most of the cases did not have occlusive arterial disease.

Adult↗