Search PubMed⌕ Search

Biomedical subjects

V Hombach

Publications and source records attributed to V Hombach.

At least 163 records · Page 9Linked to original sources
PubMed1991

Standards for analysis of ventricular late potentials using high-resolution or signal-averaged electrocardiography. A statement by a Task Force Committee of the European Society of Cardiology, the American Heart Association, and the American College of Cardiology.

Sufficient data are available to recommend the use of the high-resolution or signal-averaged electrocardiogram in patients recovering from myocardial infarction without bundle branch block to help determine their risk for developing sustained ventricular tachyarrhythmias. However, no data are available about the extent to which pharmacological or nonpharmacological interventions in patients with late potentials have an impact on the incidence of sudden cardiac death. Therefore, controlled, prospective studies are required before this issue can be resolved. As refinements in techniques evolve, it is anticipated that the clinical value of high-resolution or signal-averaged electrocardiography will continue to increase.

American Heart Association↗
PubMed1991

[In vitro balloon treatment of coronary plaque material of the human: effect of dilation time on proliferation of smooth muscle cells].

The proliferation of smooth muscle cells (SMC) seems to be an important factor in the development of restenosing events after angioplasty. Primary stenosing plaque material was obtained from human coronary arteries by thrombendarterectomy. Specimens were cut in small pieces and dilated in a flexible tube with a balloon-catheter (Medtronic 18K2030E) for 1 min., 5 min. and 10 min. at 3 atm. For the isolation of plaque cells the expant technique was used. The majority of plaque cells was identified as smooth muscle cells by positive reaction with monoclonal antibodies against smooth muscle alpha-actin. For the cultivation of SMC a mixture of Waymouth's MB 752/1 and Ham F-12 (1:1) was used. After 8 weeks cell number was analysed by a cell counter (Casy I, Schärfe System). There was a clear increase of SMC-proliferation in dependence to the duration of angioplasty (1 min. = 100%, 5 min. = 112%, 10 min. = 153%). If these data are confirmed by clinical and experimental studies, the duration of angioplasty has to be considered as a risc factor for the development of restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1991

[Restenosed growth of plaque cells from restenosed peripheral and coronary plaque material of the human in vitro: a correlation to animal experiment results following angioplasty].

In this study cells were isolated from primary-stenosing and re-stenosing tissue of human peripheral (extraction by Prof. Höfling and Dr. Bauriedel, Munich) and coronary arteries. The vast majority of plaque cells was identified as smooth muscle cells (SMC) by positive reaction with monoclonal antibodies against smooth muscle alpha-Actin. All SMC consisted of two different subpopulations, which were discriminated by different cell diameters: Relatively small cells (diameter: 18.0 +/- 4 microns, mean +/- SD) and large cells (diameter: 26.0 +/- 3 microms, mean +/- SD). Population doublings per day (PD/day) for SMC from re-stenosing lesions were significantly increased (0.60 +/- 0.13 PD/day, mean +/- SD) in comparison to SMC from primary-stenosing lesions (0.15 +/- 0.04 PD/day, mean +/- SD), p much less than 0.001). Thus, the increased growth of SMC from restenosing lesions in vitro might be the equivalent to the rapid progression of restenosing events after angioplasty in vivo. These results are in accordance with data from experimental studies after angioplasty.

Aged↗
PubMed1991

[Cell culture as a prescreening system for drug prevention of restenosis?].

Migration and proliferation of smooth muscle cells (SMC) from the media into the subendothelial space are important steps in the development of restenosing events after angioplasty; therefore a medical inhibition of this activity seems to be of clinical interest. Primary stenosing plaque material of 20 patients and restenosing plaque material of 6 patients was removed by atherectomy (Prof. Höfling, Dr. Bauriedel, Munich). For the isolation of plaque cells a mixture of Collagenase/Elastase was used. The vast majority of plaque cells was identified as smooth muscle cells by positive reaction with monoclonal antibodies against smooth muscle alpha-Actin. Propranolol (10(-4) mol/l to 10(-9) mol/l), Prednisolone (10(-3) mol/l to 10(-8) mol/l) and Etoposide (10(-4) mol/l to 10(-9) mol/l) were added to the cultures one day after seeding. After 3 days cell number and cell size distribution were analysed in a cell counter (Casy I, Schärfe System, Reutlingen). While Propranolol didn't change proliferative activity of SMC, Prednisolone caused a slight, but dose dependent inhibition of SMC-proliferation. Etoposid inhibited SMC-proliferation even below clinical concentrations to 50%. The local application of steroid or cytostatic agents might improve long term results after angioplasty. The clinical relevance of this 'Prescreening System' has to be evaluated by experimental and clinical studies.

Angioplasty, Balloon↗
PubMed1990

[Relationship of the left ventricular wall thickness to the degree of late microvascular complications in diabetes mellitus type I].

Left-ventricular wall thickness, measured by echocardiography, was determined in 111 normotensive diabetics (63 men and 48 women; mean age 26 +/- 9 years; diabetes duration 13.5 +/- 6.2 years) and 91 comparable control subjects. The interventricular septum was significantly thicker in diabetics than in controls: systolic 13.3 +/- 2.3 mm, diastolic 9.2 +/- 2.2 mm vs. systolic 12.5 +/- 2.1 mm and diastolic 8.9 +/- 1.7 mm (P less than 0.05). Posterior wall thickness measurements were: systolic 15.8 +/- 2.2 mm vs 14.6 +/- 2.0 mm (P less than 0.001), diastolic 9.5 +/- 1.8 mm vs 8.4 +/- 1.3 mm (P less than 0.01). Left-ventricular wall thickness increased stepwise with increasing severity of microvascular complications (retinopathy, nephropathy, neuropathy). There was a moderately close correlation between blood pressure values and the degree of microvascular complications (r = 0.49, P less than 0.01). These correlations indicate that increases in wall thickness are diabetes specific, but may be influenced by the level of blood pressure.

Adult↗
PubMed1990

An unusual presentation of staphylococcal pericarditis.

An atypical presentation of purulent pericarditis caused by Staphylococcus aureus is described. A bacterial etiology was initially not taken into consideration because the clinical course was torpid and afebrile. Therefore, the appropriate treatment was delayed. The patient recovered after percutaneous pericardial drainage of his purulent pericardial effusion and antimicrobial therapy. The importance of a high index of suspicion of a bacterial cause in patients with pericardial effusion of unexplained etiology is emphasized.

Bacteriuria↗
PubMed1990

Neurological outcome after a severe herpes simplex encephalitis treated with acyclovir and beta-interferon. Time course of intracranial pressure.

A severe herpes simplex encephalitis with documented intra-cerebral lesions and brain edema was treated successfully with acyclovir and beta-interferon. The increase in intracranial pressure during the second week was well controlled by ICP monitoring. Life-threatening pressure peaks were avoided through the use of thiopental, osmodiuretics, TRIS, and lidocaine.

Acyclovir↗
PubMed1990

Hemodynamic profile of carvedilol.

Several so-called multiple-action compounds have been developed, such as medroxalol (alpha and beta blockade, and beta-2 stimulation), celiprolol (alpha-2 and beta-1 blockade, and beta-2 stimulation) and carvedilol (beta blockade and vasodilatation) for the treatment of patients with arterial hypertension and with coronary heart disease. Carvedilol exerts relatively uniform peripheral effects, i.e. a reduction of both systolic and diastolic blood pressure at rest and during exercise, and a decrease in the resting and exercise heart rate. Blood pressure fall due to carvedilol may be induced by its vasodilating effect, as documented by measurements of forearm blood flow and peripheral vascular resistance. Moreover, renal hemodynamics does not seem to be significantly altered by carvedilol. Carvedilol may also produce an improvement of the LV contractile status in patients with CHD and impaired LV function, mainly due to afterload reduction, in addition to its antianginal effect, which is due mainly to the beta-blocking properties of this substance. From the studies mentioned it may be concluded that carvedilol is a useful and promising drug for treating patients with both arterial hypertension and with coronary artery disease.

Adrenergic beta-Antagonists↗
PubMed1990

Acute and chronic effects of a diuretic monotherapy with piretanide in congestive heart failure--a placebo-controlled trial.

To evaluate the acute and chronic effects of diuretic monotherapy with 3 mg piretanide bid, 46 patients (pts) with congestive heart failure (NYHA II-III) secondary to coronary artery disease were studied. Within 3 weeks of therapy, the patients lost 1.6 kg body weight. Forty-four patients reported a subjective feeling of improvement. Echocardiographically, a highly significant (p less than 0.001) reduction of diastolic and systolic diameters was found, as well as an increase of fraction shortening. Chest x-ray indicated a reduction of heart volume from 1012 +/- 263 ml to 936 +/- 233 ml (p less than 0.001). The serum potassium level remained unchanged. A subgroup of 26 pts underwent invasive hemodynamic examinations. IV injection of 6 mg piretanide resulted in an acute reduction of pulmonary wedge pressure (pc) from 20.2 +/- 5.3 mmHg to 11.9 +/- 5.0 mmHg (p less than 0.001); simultaneously a slight decrease of cardiac index from 3.2 +/- 0.6 l/min/m2 to 3.0 +/- 0.4 l/min/m2 was observed. Invasive control after 3 weeks of oral therapy showed no decline of the piretanide effect. The exercise tolerance increased clearly from 135 +/- 161 Wmin to 249 +/- 268 Wmin (p less than 0.05). A control group of further 14 pts was treated with placebo only and did not show any significant changes of pc (20.0 +/- 6.4 mmHg vs. 22.8 +/- 19.2 mmHg), exercise tolerance, or other clinical parameters. Thus, the diuretic monotherapy of congestive heart failure with piretanide is highly effective and shows a significant improvement in all clinical and hemodynamic parameters in the absence of any remarkable side effects.

Adult↗
PubMed1990

Effects of hypothyroidism on bronchial reactivity in non-asthmatic subjects.

The effect of hypothyroidism on non-specific bronchial reactivity was studied in 11 patients without pulmonary disease (mean age 40 (SD 13) years) who had had a total thyroidectomy and radioiodine treatment for thyroid cancer 41 (36) months before the study. All patients when mildly hyperthyroid while having long term thyroxine replacement treatment and once when hypothyroid two weeks after stopping triiodothyronine for the purpose of screening for metastases. Bronchial reactivity was assessed by measuring specific airways conductance (sGaw) after increasing doses of inhaled carbachol (45-1260 micrograms). The dose producing a 35% decrease in sGaw (PD35) was determined from the cumulative log dose-response curve by linear regression analysis. Mean baseline sGaw values were similar when the patients were hypothyroid and when they were hyperthyroid (1.35 (0.36) and 1.41 (0.56) s-1 kPa-1). The interstudy coefficients of variation of baseline sGaw were higher in the thyroid patients than in a euthyroid control group (14% versus 8%). Geometric mean PD35 was lower when the patients were hypothyroid (97 micrograms) than when they were mildly hyperthyroid (192 micrograms). It is concluded that acute hypothyroidism increases non-specific bronchial reactivity in nonasthmatic subjects.

Acute Disease↗
PubMed1990

Pharmacologic blockade of the left stellate ganglion using a drug-reservoir-pump system.

Patients suffering from the long QT syndrome (LQTS) are threatened by sudden arrhythmic cardiac death. This case report describes a new therapeutic approach to ventricular tachyarrhythmias refractory to oral pharmacological treatment (propranolol + phenytoin) using a drug-reservoir-pump system for the pharmacologic blockage of the left stellate ganglion.

Adult↗
PubMed1990

[Localization of premature and ectopic ventricular depolarization using a new nuclear medicine tomographic technique].

In planar radionuclide ventriculography (RNV) identification of the site of initial contraction is possibly by the Fourier phase. First clinical experiences will be presented with a new integrated tomographic technique--ISPECT--in noninvasively assessing the site of ectopic or premature ventricular depolarization. In six patients Fourier phases of RNV and ISPECT were performed and compared in five with results from the corresponding electrophysiologic study. It was possible to exactly localize the beginning of mechanical contraction in the two orthogonal planes: during pacemaker stimulation at the apex of the right ventricle, at the lateral border of a large aneurysm during ventricular tachycardia, and at the site of three of five WPW bundles. In the other two bundles the site of first contraction was near the area found during invasive mapping procedure. Thus, this new ISPECT approach together with planar radionuclide imaging may help in noninvasively localizing the site of ectopic and premature depolarization in addition to surface ECG.

Adult↗
PubMed1990

Timing of valve replacement in chronic aortic regurgitation. A pathophysiological approach.

Timing of valve replacement (AVR) in chronic aortic regurgitation remains a difficult problem in clinical practice. When the disease takes a favorable natural course, this may be attributed to excellent compensatory mechanisms - especially an increase in left ventricular end-diastolic volume (LVEDV) in relation to regurgitant volume (RV) - whereas a rapid clinical and hemodynamic deterioration may usually be ascribed to a vicious circle consisting in a marked increase in afterload leading to an increase in LVEDV and so on. 54 patients with aortic regurgitation underwent pre- and postoperative as well as long-term follow-up radionuclide ventriculographic (RNV) studies in order to determine LVEDV and RV and to measure left ventricular ejection fraction (LVEF). These measures were expected to provide information on 'physiologic' LVEDV elevation in relation to RV. Our results indicate that if LVEDV exceeds 300-400 ml there may be an increase in afterload for LV. Factors counteracting this increased afterload (LV hypertrophy, increased diastolic stretching) will eventually preserve LVEF and keep LVEDV/RV within the normal range, but are accompanied by an elevation of LV filling pressure leading to dyspnea on exertion. With an LVEDV exceeding 400-500 ml these factors generally cannot prevent the initiation of the above mentioned vicious circle. Hence, in these severely symptomatic cases LVEDV/RV exceeds the normal range and LVEF becomes markedly depressed. An unfavorable postoperative result must be expected in these patients, while the postoperative result will be good in cases with an LVEDV/RV within the normal range. Hence, we conclude that AVR should ideally be performed in those patients with an EDV exceeding 300 ml, who still have an LVEDV/RV within the normal range, but who show clinical symptoms and/or an only moderately depressed LVEF, indicating that the limits of the compensatory mechanism are reached. The indications for AVR in other conditions characterized by the clinical status, the level of the LVEDV and LVEDV/RV are discussed.

Adult↗
PubMed1990

[Angioplasty using high-frequency energy in coronary stenosis].

The most notable limitations of balloon dilatation, acute vascular occlusion with a rate of 3 to 5% and restenosis rate of 20 to 40%, appear at least partially attributable to the mechanism of luminal widening--tearing of the intima and plastic restructuring of plaque material. Alternative angioplasty methods, with the exception of stent implantation, are based on the concept of rendering plaque material, by excision and ablation, with a smoother and less thrombogenic interior surface and to lower the risk of renewed proliferation. Plaque material is removed in three ways: mechanical, by excision; thermically, by laser with relatively low energy density or by high-frequency alternating current; non-thermically, by photoablation with laser of very high energy impulse density. High-frequency alternating current as an energy source for thermic angioplasty is used in four technically different forms of application (Table 1): as indirect or direct high-frequency angioplasty in the scope of the "spark erosion" technique and for heating a balloon during balloon dilatation to achieve thermofusion of the tissue for stabilization of the angioplasty results. With indirect hot-tip high-frequency angioplasty the high-frequency alternating current is employed to rapidly heat an olive-shaped fully isolated metal tip with an integrated resistor, plated with gold to avoid adhesion of thrombotic material. The heat emitted is directed radially. The currently-available system consists of a 20-Watt high-frequency generator with 5 MHz. On application of 10 Watts to tissue in water at 37 degrees C, the temperature achieved at the catheter tip is 130 to 140 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗