Search PubMed⌕ Search

Biomedical subjects

M Vogt

Publications and source records attributed to M Vogt.

At least 127 records · Page 7Linked to original sources
PubMed1992

Treatment of mycotic aneurysm of the aorta and its branches: the location determines the operative technique.

Twenty-seven patients with mycotic aneurysms of the aorta and its major branches were operated on between 1969 and 1991. There were 24 males and three females ranging in age from 6 to 84 years (mean age for adults 63 years). Sixteen of the 27 (59%) aneurysms were ruptured and in situ repair was undertaken in 20 (74%) patients. The mean follow-up was 5.8 years (range: 8 months to 16 years). Four patients (15%) died during the hospital stay and 23 survived. There were eight late deaths, two of which were a direct result of the aneurysm. The estimated 1- and 5-year survival rates were 62 and 36%, respectively. Extra-anatomic reconstruction is the method of choice for the majority of patients with mycotic aneurysm of the infrarenal abdominal aorta and iliac arteries. In situ repair after an extensive debridement of the aneurysmal wall and all infected tissue combined with antibiotic therapy is a satisfactory method of treating mycotic aneurysms of other locations, and for a highly selected group of patients with infrarenal mycotic aortic aneurysms.

Adult↗
PubMed1992

Axillo-femoral bypass and simultaneous removal of the aorto-femoral vascular infection site: is the procedure safe?

In a retrospective analysis 12 patients treated for aorto-femoral vascular infections between 1984 and 1990 were evaluated. They were all male with a mean age of 63 years. Indications for treatment were: mycotic aneurysms-3, primary aorto-enteric fistula-2 and graft infection-7. Surgical treatment consisted of implantation of an extra-anatomic bypass, carefully avoiding the infected area, followed by removal of the infected graft and tissue at the same session. There was no early mortality (less than 30 days) but the first year mortality was 42% (n = 5). Causes of death were: aortic stump disruption (n = 1), recurrence of aorto-enteric fistula (n = 2), axillary anastomosis disruption (n = 1), cardiac failure (n = 1). Orthotopic reconstruction of the aorta after 12 months, as we advocate, was accomplished in two patients and is scheduled in another one. In two patients their poor condition precluded this second step, and in two further patients above-knee amputation with subsequent extra-anatomic graft removal was needed. Only one of the 12 extra-anatomic bypasses became infected. Reconstruction by axillo-femoral bypass combined with removal of the aorto-femoral graft at the same session is a practicable procedure with good early results. However, the rate of successful orthotopic reconstruction of the aorta after 12 months is low because of a high mortality rate, especially in the presence of aorto-enteric fistulas, and because some patients with well functioning axillo-femoral grafts are in too poor condition for another large operation.

Aged↗
PubMed1992

Pharmacotherapeutic effects of antihypertensive agents on myocardium and coronary arteries in hypertension.

Hypertensive left ventricular hypertrophy comprises myocyte hypertrophy, interstitial fibrosis and structural alterations in the coronary microcirculation. This leads to impairment of diastolic function in the left ventricle and coronary flow reserve despite normal epicardial arteries. Consequently, antihypertensive treatment should aim at (1) reversing myocyte hypertrophy, (2) restoring myocardial structure and (3) improving coronary flow reserve without lowering blood pressure. In recent years many clinical studies have shown that regression of hypertensive hypertrophy can be induced by long-term treatment with ACE inhibitors, calcium-channel blockers, beta-receptor blockers and antisympathonic drugs. However, vasodilators and diuretics, which stimulate adrenoceptor activity and increase angiotensin II levels, were found to be less effective in reversing left ventricular hypertrophy. The trophic influence of catecholamines and angiotensin II on the myocardium counteracts the effect of systolic wall stress reduction due to blood pressure lowering. As regards reversal of interstitial fibrosis, ACE inhibitors seem to be effective, because fibroblast growth was found to be stimulated by angiotensin II. Recently, clinical studies have confirmed previous experimental data that improvement in impaired coronary vasodilator reserve can be realized by long-term antihypertensive therapy. In adopting an antihypertensive treatment strategy prime consideration should be given to reversal of cardiac remodelling through restoration of myocardial structure and repair of the coronary microcirculation.

Animals↗
PubMed1992

Coronary haemodynamics in hypertensive heart disease.

Cardiac constituents affected in arterial hypertension comprise the myocardium, interstitium and coronary circulation. With regard to coronary circulation, arterial hypertension is an important risk factor in coronary artery disease, but even in the absence of coronary artery disease, hypertensive patients frequently have angina pectoris or reveal electrocardiographic abnormalities suggestive of myocardial ischaemia due to coronary insufficiency. Under clinical conditions, determination of coronary flow reserve (dipyridamole; Argon-method) allows for the evaluation of impairment of coronary regulatory reserve. In comparison to healthy normotensives, coronary haemodynamics in hypertensive patients with microvascular angina are characterized by a severely increased minimal coronary resistance and reduced maximal coronary blood flow to dipyridamole. Accordingly, coronary reserve is markedly reduced by about 40%, and metabolic, myocardial and vascular factors may be involved in this reduction. In the compensated stage of arterial hypertension, with concentric left ventricular hypertrophy, myocardial factors, such as myocyte hypertrophy, extravascular compressing forces and functional implications of impaired relaxation, as well as metabolic factors, contribute to impairment in coronary reserve to a minor extent. The reduction in coronary flow reserve is not proportional to the elevation in left ventricular muscle mass and thus the degree of left ventricular hypertrophy does not seem to determine the reduction in vasodilator reserve directly. Thus the reduction in coronary reserve seems to be primarily the consequence of an impaired vasodilating capacity of the coronary resistance vessels, as indicated by a severely increased minimum coronary resistance to dipyridamole, i.e. a severely reduced overall coronary conductance capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1992

Electrophysiological and therapeutic implications of cardiac arrhythmias in hypertension.

UNLABELLED: Hypertension, especially if associated with left ventricular hypertrophy (LVH), is a risk factor in complex ventricular arrhythmia (VA) and sudden cardiac death (SCD). To determine the effectiveness of the clinical use of programmed ventricular stimulation (PVS) we studied 40 symptomatic hypertensive patients after excluding coronary heart disease (CHD), as characterized by dizziness and palpitation, syncope, aborted SCD and/or documented complex VA. PVS revealed a normal result, i.e. a maximum of six ventricular echobeats, in 70% (group A) and a pathological result, i.e. ventricular tachycardia (VT) or fibrillation (VF) in 30% (group B). Both groups differed significantly with respect to LV (left ventricular) muscle mass: 158 +/- 45 (A) vs. 222 +/- 112 (B) g.m-2, LVEF (left ventricular ejection fraction): 71 +/- 17% (A) vs. 47 +/- 18% (B) and LV end-systolic volume index: 34 +/- 25 (A) vs. 63 +/- 27 (B) ml.m-2. Coronary reserve was comparably reduced in both groups: 2.6 +/- 1.0 (A) vs. 2.3 +/- 0.6 (B). In 3/8 (37%) patients with aborted SCD and VT/VF the clinical VA (2/2 VT and 1/6 VF) could be induced, whereas in the remaining five patients nsVT or no complex VA was induced. The therapeutic regimen included no drugs in 30%, beta-blockers in 50%, serial drug testing in 12% and implantation of an automatic cardioverter defibrillator (AICD) in 8% of patients. Ventricular late potentials (LPs), detected by the signal averaging electrocardiogram, represent zones of delayed myocardial activation, which may become an origin of ventricular tachycardias. Three criteria constitute a positive LP: (1) QRS duration greater than 114 ms, (2) root mean square voltage of the last 40 ms less than 20 microV and (3) duration of low amplitude signal below 40 microV greater than 38 ms. To look for the prognostic value of LP in hypertension we investigated 43 hypertensive patients without evidence of CHD. All three criteria were positive in 4/43 patients (9%), three of them demonstrating inducible monomorphic VT during PVS. 17/30 patients (56%) with LVH had at least one positive criterion, whereas only one out of 13 patients without left ventricular hypertrophy (8%) had one positive criterion. Symptomatic patients presenting with syncope, aborted SCD or documented VT/VF differed significantly from patients without symptoms or complex arrhythmias in regard to all three criteria. CONCLUSION: In hypertensive heart disease clinical arrhythmias as well as the result of electrophysiological testing are closely related to left ventricular performance and hypertrophy.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1992

Reduced peripheral and coronary vasomotion in systemic hypertension.

In 53 patients with a history of arterial hypertension and 16 normotensive control subjects, coronary blood flow reserve by means of the argon method, and peripheral vascular flow reserve by means of venous occlusion plethysmography, were studied. The coronary flow reserve, expressed as the ratio of coronary vascular resistance under resting conditions to the minimal coronary vascular resistance after the administration of dipyridamole, was 4.34 +/- 0.89 in the normotensive group and 2.18 +/- 0.60 in the hypertensive group. There was no significant difference in forearm peak flow after 3 min of arterial occlusion between normotensive and hypertensive patients, while the peripheral minimal vascular resistance was significantly higher in hypertensive patients (8.8 +/- 3.8 mmHg x ml.min-1 x 100 ml-1 tissue) as compared to normotensive subjects (6.37 +/- 2.37 mmHg x ml.min-1 x 100 ml-1 tissue). Parallel to the reduction in coronary reserve, the peripheral flow reserve, expressed as the ratio of peripheral resting vascular resistance to peripheral minimal vascular resistance after 3 min of arterial occlusion, was significantly lower (P less than 0.01) in hypertensive subjects (3.85 +/- 2.28) as compared to normotensive subjects (5.31 +/- 1.72). These data suggest that in hypertensives an impaired vasodilator reserve of both coronary and peripheral microcirculation exists.

Angina Pectoris↗
PubMed1992

[Prevention with vasoactive drugs].

Arterial hypertension is the most frequent cause of a disturbance of coronary microcirculation. Inspite of having normal epicardial coronary arteries, patients with arterial hypertension often have symptoms of angina pectoris and a positive exercise tolerance test. The angina pectoris symptoms in patients with arterial hypertension are due to functional and structural alterations of the coronary microcirculation. Consequently, an antihypertensive therapy should not only aim at lowering blood pressure and reversing myocardial hypertrophy, but also to improve coronary microcirculation in order to avoid the consequences of chronic ischemia on the myocardium. Until now, only experimental studies have indicated that antihypertensive therapy can improve coronary flow reserve. To determine (also under clinical conditions) if coronary flow reserve can be improved, in 30 hypertensive patients maximal coronary blood flow, minimal coronary resistance, and coronary reserve (dipyridamol) were studied before and after a long-term antihypertensive treatment (9-12 months) with an ACE-inhibitor (enalapril 10-20 mg/d), a calcium channel blocker (diltiazem 120-180 mg/d) and a beta 1-selective beta-receptor-blocker (bisoprolol 5-10 mg/d). To assess the chronic effects rather than the acute effects of the antihypertensive pharmacon, coronary microcirculation was studied after intermission of medical therapy for a period of 1 week. Along with a comparable decrease in LV muscle mass, coronary reserve was improved after enalapril by 48%, after diltiazem by 48%, and after bisoprolol by 22%. It is possible that the observed increase in coronary reserve is related to the reversal of structural vascular abnormalities on the level of the coronary microcirculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

A multicentre evaluation of the Ektachem DT60-, Reflotron- and Seralyzer III systems.

The analytical performance of the three analytical systems Reflotron, Ektachem DT60 and Seralyzer III was studied according to ECCLS guidelines (1) and partly according to a protocol of the Société Francaise de Biologie Clinique (SFBC) (2) in a multicentre evaluation involving four laboratories. The determination of 11 analytes led to more than 180,000 data. With the Ektachem DT60, imprecision was acceptable for all analytes except for sodium. With the Reflotron, imprecision for glucose and creatinine was wider than the acceptable limits. With the Seralyzer III, imprecision for glucose, uric acid, cholesterol, creatinine and potassium was not within acceptance limits. The recovery of system assigned control sera values was acceptable for all analytes, except for glucose, creatinine and sodium with the Ektachem DT60 system, and for all but glucose and cholesterol with the Reflotron. On the Seralyzer III, the limits of acceptance were exceeded only with the creatinine assay. The recovery of the reference method values with Kontrollogen L caused problems with all three systems and for all analytes. Only 30% of the mean values of Kontrollogen L measured with the Ektachem and with the Seralyzer III were within the limits of acceptance. 40% of the mean values determined with the Reflotron were inside these limits. The upper limits of linearity as claimed by the manufacturers were obtained with all analytes and systems with the exception of cholesterol on all systems and the creatinine assay on the Seralyzer III. The systems under test and several different comparison methods showed good agreement for the analysis of patient samples, except in one laboratory for the analysis of sodium and aspartate aminotransferase with the Ektachem system and potassium with the Seralyzer III. Turbidity showed no significant influence on the measurements of all analytes and all systems. Haemolysis, hyperproteinaemia, and bilirubinaemia affected several methods on all three systems. A start time delay of up to 60 s did not affect the results of the Reflotron, except in the case of the triacylglycerol assay, which was affected by start time delays greater than 45 s. The results of 4 assays on the Seralyzer III were decreased considerably by a delayed start time (triacylglycerols and creatinine above 5 s, aspartate aminotransferase above 35 s and creatine kinase above 15 s). For reliable results from all the assays in each of the three analytical systems, it was necessary to use the prescribed sample volume within certain limits. The practicability of all analytical systems tested was found to be very good. A field study was conducted with the Reflotron system. The analyte concentration was determined in venous blood from various patients. In 25 out of 30 experiments, the results of the "field" laboratories showed a greater spread about the fitting line than those obtained in the "expert" laboratories.

Chemistry, Clinical↗
PubMed1992

[Mycotic aneurysm of the infrarenal aorta: surgical possibilities and results].

Between 1973 and 1990 eleven patients with mycotic aneurysm of the abdominal aorta underwent surgery. Extra-anatomic axillobifemoral bypass with aortic ligation and aneurysm excision was performed in 5 patients, and in situ reconstruction in 6. There were 3 early and 3 late deaths. Regardless of the type of operation, surgery of mycotic aneurysm is followed by severe postoperative complications with high the early and the late mortality rates.

Aged↗
PubMed1991

Evidence of endothelial dysfunction in coronary resistance vessels in patients with angina pectoris and normal coronary angiograms.

This study determines whether an impaired endothelium-mediated vasodilation in coronary resistance vessels exists in patients with microvascular angina. In 23 patients with clinically suspected coronary artery disease and smooth coronary arteries in the angiogram, coronary flow in response to an endothelium-related (acetylcholine) and endothelium-unrelated (dipyridamole) vasodilation was measured. Coronary flow was determined by the gas-chromatographic argon method (1) before, (2) with intracoronary acetylcholine infusion, and (3) after dipyridamole administered intravenously. In 8 patients, acetylcholine did not significantly increase coronary flow (from 91 +/- 28 to 118 +/- 37 ml/min.100 g), whereas flow was greatly increased after administration of dipyridamole (258 +/- 97 ml/min.100 g), indicating an endothelium-related vasodilator defect. In 6 patients, neither acetylcholine nor dipyridamole caused a significant increase in coronary flow, indicating an impaired coronary vasodilation on the vascular site. In 6 patients, coronary flow increased markedly after both administration of both acetylcholine and dipyridamole (from 81 +/- 26 to 191 +/- 68 and 234 +/- 87 ml/min.100 g). In 3 patients given acetylcholine, coronary artery constriction occurred. No significant correlation was found between the response to acetylcholine and that to dipyridamole (r = 0.40, p = not significant). The results indicate that in a subgroup of patients with smooth coronary arteries angina can be caused by an abnormality of the endothelial function in the microcirculation.

Acetylcholine↗
PubMed1991

[Actinomycosis--clinical and therapeutic considerations based on 2 personal case reports].

We report on two patients with actinomycosis. The first case was a 45-year-old cachectic man with extensive bilateral pulmonary infiltrates. The lesions remained unclear for 18 months and only open lung biopsy with microscopic and cultural evaluation led to the diagnosis of actinomycosis. In the second case, classic cervico-facial actinomycosis in a 69-year-old farmer is described. Diagnosis was established on the basis of microscopic findings of "sulphur granules" eroding the mandible. Furthermore, the clinical presentation, with an indurated swelling of the jaw and intraoral fistula formation, was typical. The patient had a severe combined aortic valve lesion and died after ventricular fibrillation during hospitalization. Diagnosis could not be confirmed by culture, probably due to antibiotic prophylaxis against endocarditis during tooth extraction on the first day of admission. Diagnostic difficulties and microbiologic aspects are discussed, with special focus on the rare species of Actinomyces meyeri which was cultured from biopsy specimens from the lung of the first patient. So far this species has been described in only 13 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomycosis↗
PubMed1991

Long-term treatment in arterial hypertension for protecting hypertrophic myocardium.

The cardiac organ manifestation of arterial hypertension comprises the myocardium itself with left-ventricular hypertrophy, the interstitium with perivascular and interstitial fibrosis, and the coronary circulation with disease of large and small coronary arteries. The consequences of the sum and interactions of these cardiac organ manifestations have an impact on left-ventricular systolic and diastolic function, the ischemic risk, and the occurrence of arrhythmias in hypertensive patients. As the prognosis of arterial hypertension is determined, to a considerable extent, by these cardiac complications, the aim of treatment of hypertensive heart disease is reversal of the myocardial hypertrophy in order to prevent later progression to hypertensive failure. A further goal of therapy is reversal of hypertensive coronary microangiopathy in order to improve the coronary reserve and to reduce the ischemic risk. Regression of hypertrophy can be induced by suitable antihypertensive drugs (calcium channel blockers of the dihydropyridine type, ACE inhibitors, and sympatholytic substances). While normal systolic function was maintained in the compensated stage of hypertensive hypertrophy and was not significantly influenced by antihypertensive therapy, diastolic function was impaired in a very early stage of arterial hypertension. Both the phase of isovolumic relaxation and the phase of early diastolic filling were imparied, while after long-term antihypertensive treatment with Ca-channel blockers of the dihydropyridine type or ACE inhibitors, only the latter one was improved. From preliminary results there is clinical evidence that hypertensive disease of small coronary arteries can be reversed after long-term antihypertensive treatment with a consequently improved coronary reserve and a reduced ischemic risk. Moreover, to what extent the prognosis of hypertensive heart disease can be improved by reversal of myocardial hypertrophy and disease of small coronary arteries is yet unknown.

Cardiomegaly↗
PubMed1991

Preoperative assessment of the likelihood of infection of the lower respiratory tract after cardiac surgery.

Lower-respiratory-tract infections are among the most frequent complications observed in the intensive care unit, leading to delayed postoperative recovery time and increased costs and mortality. We have tried to evaluate the prognostic value of perioperative bacteriology of tracheal aspirates in assessing the risk of such complications. In a prospective study aspirates of 100 patients undergoing cardiac surgery were taken immediately after intubation and were analysed for microorganisms by Gram-stain and microbiological cultures using standard procedures. All patients received perioperative antibiotic prophylaxis with a single dose of 2 g ceftriaxone intravenously. From 26 patients with bacteriologically positive tracheal secretion, 8 (30.7%) developed lower respiratory tract infection whereas only 1 of 72 patients (1.4%) with negative bacteriological results developed this complication. Smoking (p less than 0.01) and abnormal preoperative lung function (p less than 0.01) were significantly more frequent in patients developing postoperative pneumonia. Regarding the results of this study, the risk of developing pulmonary infection in the early postoperative course after cardiac surgery can be estimated from the tracheal aspirates.

Adult↗
PubMed1991

A method for the quantification of intracellular zidovudine nucleotides.

An assay to quantify the phosphorylation products of zidovudine (AZT) in peripheral blood mononuclear cells (PBMC) was developed. Extracts of PBMC were separated by high-performance liquid chromatography. Eluted AZT mono- (MP), di- (DP), and triphosphate (TP) were collected in separate portions. Treatment with alkaline phosphatase yielded equimolar amounts of AZT, which after solid-phase enrichment were assayed by radioimmunoassay. Detection limit was 0.1 pmol/10(6) PBMC for each nucleotide. Recoveries of 102%-118% were observed. AZT nucleotides were measured in samples from three patients receiving 250 mg of AZT every 12 h. Intracellular concentrations of AZT-MP after 1-2 h ranged from 0.9 to 1.4 pmol/10(6) PBMC and then declined to 0.3-1.1 pmol/10(6) PBMC after 4 h. AZT-DP and AZT-TP reached concentrations of 0.3-0.5 pmol/10(6) PBMC after 1-2 h and could not be detected after 4 h in any of the three patients. Duplicate determinations deviated by less than 20%.

Alkaline Phosphatase↗
PubMed1991

Coronary circulation in arterial hypertension.

Arterial hypertension is the most common cause of congestive heart failure and an important risk factor in coronary artery disease (CAD). However, even in the absence of CAD, coronary reserve is frequently impaired in hypertensive patients. To study whether the reduced coronary reserve is due to the degree of left ventricular hypertrophy (LVH) or is a consequence of primary vascular alterations, coronary reserve was determined in 31 hypertensive patients (age of 56 +/- 10 years; systolic/diastolic blood pressure of 167 +/- 18/98 +/- 9 mm Hg) with angina pectoris and normal coronary angiogram. Coronary reserve was determined by measuring coronary resistance before and after dipyridamole (0.5 mg/kg of body weight i.v.). Coronary blood flow was measured quantitatively by the gas chromatographic argon method. LV muscle mass was measured by ventriculography. Twelve normotensive patients (age of 52 +/- 8 years) were studied for comparison. Coronary resistance was 20% higher in hypertensive than in normotensive patients, whereas coronary blood flow at rest was not significantly different. The maximal coronary blood flow after dipyridamole was 40% lower in hypertensive than in normotensive patients; accordingly, minimal coronary resistance was significantly increased by 112% in hypertensive patients (p less than 0.0005). Coronary reserve was reduced by 37% (p less than 0.001) in hypertensive patients compared with normotensive patients. Between the impairment in coronary reserve and left ventricular muscle mass, no significant correlation (r = 0.024, n.s.) was found. The impaired coronary vasodilator reserve is reflected by episodes of transient myocardial ischemia during ST-segment monitoring.

Animals↗