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Biomedical subjects

V Hombach

Publications and source records attributed to V Hombach.

At least 127 records · Page 7Linked to original sources
PubMed1993

Lack of effect of nitrates on exercise tolerance in patients with mild to moderate heart failure caused by coronary disease already treated with captopril.

OBJECTIVE: To test the hypothesis that the addition of nitrates improves exercise tolerance in patients with heart failure caused by coronary artery disease already treated with an angiotensin converting enzyme inhibitor and diuretics. DESIGN: Randomised, double blind, placebo controlled, 16 week treatment periods. SETTING: Outpatient clinic at a university hospital. PATIENTS: 54 patients with previous myocardial infarction, symptoms of mild to moderate heart failure, left ventricular ejection fraction below 40%, no exercise-induced angina or electrocardiographic signs of ischaemia. Four patients in the nitrate group (n = 24) and one patient of the placebo group (n = 25) were withdrawn from the study. INTERVENTION: After the patients had been on constant doses of captopril and diuretics for at least 2 weeks, they were randomised to receive a target dose of 40 mg isosorbide dinitrate twice daily or placebo in addition to the continuation of captopril and diuretics. MEASUREMENTS: Bicycle exercise tests with measurement of gas exchange were carried out before randomisation and after 1, 6, 12, and 16 weeks of the double blind treatment. The change in peak oxygen uptake from control to week 16 was prospectively defined as the main outcome measure. RESULTS: The increase in peak oxygen uptake from before randomisation tended to be greater in the placebo group (before randomisation 17.4 (3.4) ml/min/kg) than in the nitrate group (before randomisation 17.1 (3.5) ml/min/kg) after 12 weeks (mean increase 1.1 (2.7) v 0.0 (2.7) ml/min/kg, p < 0.12) and 16 weeks (1.7 (3.0) v 0.3 (2.6) ml/min/kg, p < 0.14) of treatment. CONCLUSION: The addition of nitrates to a baseline treatment consisting of captopril and diuretics did not improve exercise tolerance.

Adult↗
PubMed1993

Ultrasound-guided positioning of temporary pacing catheters and pulmonary artery catheters after echogenic marking.

Pacing of the heart is one of the most effective emergency measures in the management of critical bradycardic arrhythmias. Positioning of the pacing catheter is safest under fluoroscopic control; however, this facility is not always readily available in emergency situations. A procedure was therefore developed by which pacing catheters could be easily positioned under echocardiographic control after echogenic marking. It involves the filling of commercially available balloon-tipped pacing catheters with an echogenic substance consisting of galactose microparticles suspended before use in a 0.9% saline solution (Echovist). The balloon on the pacing catheter is then easy to locate intravascularly by ultrasound and can be visually guided into the right ventricle. To date, this method has been used effectively and without complication to position both pacing catheters and pulmonary artery catheters.

Adult↗
PubMed1993

[The noninvasive determination of resting myocardial blood flow in patients using 82 Rb in comparison with the argon method].

Resting myocardial blood flow in absolute units was determined in 11 patients without known heart disease using dynamic PET with 82Rb. Based on a modified Fick's approach to measuring myocardial blood flow, originally developed and validated in canine studies by Herrero and coworkers (Circulation 1990; 82: 1377-86), a global flow value of 0.60 +/- 0.10 ml/min/gr myocardium (MV +/- SD, N = 11) was obtained. With the exception of the apex, segmental blood flow was not significantly different in 12 left ventricular myocardial segments, indicating homogenous myocardial blood flow distribution. In 5 patients global myocardial blood flow was determined simultaneously both by 82Rb PET and argon as inert gas method. 82Rb flow did not differ significantly from argon flow (0.60 +/- 0.05 vs. 0.68 +/- 0.15, MV +/- SD, N.S.). These results show that correct quantitation of resting myocardial blood flow with dynamic 82Rb PET is feasible also in patients.

Adult↗
PubMed1993

[The diagnostic value of standard ECG methods, the cold-pressure test and Valsalva maneuver in idiopathic QT syndrome].

The idiopathic Long QT Syndrome is an infrequently occurring disorder. Affected patients usually show ECG alterations and are prone to syncope and sudden arrhythmic cardiac death. Adequate therapy with beta-blocking drugs may significantly improve the prognosis of affected patients. The early and precise diagnosis of the disorder therefore has major prognostic impact. This paper reports the diagnostic significance of standard ECG, exercise stress testing, ambulatory ECG monitoring, cold pressor test and Valsalva maneuver in 14 patients with Long QT Syndrome. The results were compared with those obtained in 14 healthy age matched volunteers. QTc duration was significantly longer in patients with Long QT Syndrome during standard 12-lead ECG at rest (489 +/- 55 ms versus < vs. > 412 +/- 25 ms, p < 0.005), exercise stress test (490 +/- 39 ms vs. 409 +/- 18 ms, p < 0.001), cold pressor test (512 +/- 45 ms vs. 407 +/- 19 ms, p < 0.001), Valsalva maneuver (497 +/- 49 vs. 407 +/- 18 ms, p < 0.001), minimal heart rate during 24-h of ambulatory ECG monitoring (482 +/- 69 ms vs. 402 +/- 22 ms, p < 0.01) and maximal heart rate during Holter monitoring (460 +/- 47 ms vs. 411 +/- 27 ms, p < 0.005). Four of 14 patients with Long QT Syndrome had pathological findings during ambulatory ECG monitoring (two patients showed short episodes of asymptomatic torsade de pointes tachycardia, one patient had an intermittent SA-Block, and one patient showed T-wave alternans). All healthy volunteers had normal ambulatory ECG recordings (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Significance of noninvasive diagnostic techniques in patients with long QT syndrome.

The idiopathic long QT syndrome (LQTS) is an infrequently occurring disorder. Affected patients may have electrocardiographic alterations and are prone to syncope and sudden arrhythmogenic cardiac death. Adequate therapy may improve the prognosis of affected patients significantly. Therefore the early and precise diagnosis of LQTS has major prognostic impact. This study reports the diagnostic significance of standard electrocardiographic techniques and autonomic maneuvers in 14 patients with LQTS. The findings are compared with those of 14 healthy age-matched control persons. QTc duration was significantly longer in patients with LQTS during standard 12-lead electrocardiography (489 +/- 56 vs 412 +/- 30 ms, p < 0.005), exercise stress testing (490 +/- 38 vs 409 +/- 18 ms, p < 0.001), cold pressor testing (512 +/- 45 vs 407 +/- 19 ms, p < 0.001), Valsalva maneuver (497 +/- 49 vs 407 +/- 19 ms, p < 0.001), minimal heart rate during 24-hours of ambulatory electrocardiographic recording (482 +/- 69 vs 402 +/- 22 ms, p < 0.01) and maximal heart rate during Holter monitoring (460 +/- 47 vs 411 +/- 27 ms, p < 0.005). Four of 14 patients with LQTS had pathologic findings during ambulatory electrocardiographic monitoring (2 patients with short episodes of torsades de pointes tachyarrhythmia, 1 patient with intermittent sinoatrial block, and 1 patient with intermittent TU-wave alterations), whereas all control persons had normal ambulatory electrocardiographic recordings (p < 0.05). Thus, noninvasive standard electrocardiographic techniques in combination with autonomic maneuvers may contribute significant information for a precise diagnosis in patients with suspected LQTS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Massive main pulmonary artery embolism diagnosed with two-dimensional Doppler echocardiography.

This report describes the usefulness of echocardiography in the differential diagnosis of acute cardiovascular events. In a 66-year-old patient with known aortic stenosis and mitral valve prosthesis, who suddenly deteriorated with severe dyspnea, a thrombus within the pulmonary artery could be detected with 2-D echo. Pulsed-wave Doppler disclosed the resulting flow-velocity disturbances.

Aged↗
PubMed1992

Excimer laser coronary angioplasty: experience with a prototype multifibre catheter in patients with stable angina pectoris.

Percutaneous excimer laser coronary angioplasty (ELCA) was performed in a first group of 20 patients with stable angina pectoris caused by significant coronary stenosis, and long-term follow-up was evaluated. Prototype 4 to 5.5 French multifibre catheters with 18-20 quartz fibres of 100 microns diameter, concentrically arranged around a central lumen for taking up a guide wire, were coupled to a commercial XeCl excimer laser. Energy was delivered at a wavelength of 308 nm with a pulse duration of 60 or 120 ns. Operating at a repetition rate of 20 Hz, mean energy transmission was 13.4 +/- 6.8 mJ per pulse. In all but one patient the lesion could be passed by the catheter. Percent diameter stenosis decreased from 77.1 +/- 10.8% to 53.1 +/- 11.8% after ELCA. Complications were frequently observed, intracoronary thrombus formation in eight instances, dissection in six patients and spasm in five cases, causing total vessel occlusion in five procedures. All complications could be managed efficaciously by thrombolytic and vasodilating drugs and/or balloon angioplasty. Subsequent PTCA was performed in case of complication or insufficient stenosis reduction after ELCA in 18 patients with adequate results (residual stenosis, 28.5 +/- 10.2%). Long-term follow-up angiography, which could be performed in 16 of 19 laser treatments, demonstrated significant restenosis in only three patients. Our preliminary results suggest that, using ELCA, ablation of atherosclerotic lesions is feasible in most cases. However, compared with PTCA, stenosis reduction is significantly less, and the acute complication rate is much higher. Thus, further improvements of the catheter system are necessary in order to realize the advantages of excimer laser ablation, which can be demonstrated by experimental studies.

Adult↗
PubMed1992

Magnetocardiographic non-invasive localization of accessory pathways in the Wolff-Parkinson-White syndrome by a multichannel system.

Electrical activity can be localized by magnetocardiography (MCG) non-invasively. In this study a 37-SQUID (Super Conducting Quantum Interference Device) sensor multi-channel system (KRENIKON) was used to assess the potential of magnetocardiography to localize accessory pathways with a multichannel system. Seven WPW patients were studied by means of magnetocardiography. Prior to the MCG recordings, the site of the accessory pathway had been determined in all patients by invasive catheter mapping. MR images of the heart were used for anatomical correlation. The magnetocardiographic localization of the accessory pathway corresponded with catheter mapping within 2.1 cm on average (total range: 0-5 cm). This is thus, a promising new method for non-invasive localization of accessory pathways in WPW patients.

Adult↗
PubMed1992

Direct current application: easy induction of ventricular fibrillation for the determination of the defibrillation threshold in patients with implantable cardioverter defibrillators.

For the determination of the defibrillation threshold, the induction of ventricular fibrillation is mandatory. However, in severely damaged hearts it is sometimes difficult to induce ventricular fibrillation by rapid stimulation or alternating current. Only rapid nonclinical ventricular tachycardias may result, and their cardioversion threshold may be different from the defibrillation threshold. Therefore, it was the purpose of this study to test the potential of direct current (DC) application to rapidly induce ventricular fibrillation in patients with an implanted cardioverter defibrillator. The defibrillation threshold had to be determined in 13 patients (9 with coronary heart disease, 4 with dilative cardiomyopathy, ejection fraction 35%) during and 2 weeks after the implantation of a cardioverter defibrillator. DC was applied 37 times by a commercially available 9-V DC battery via a bipolar catheter for about 3 seconds. Ventricular fibrillation was induced 23 times (62%) and rapid nonclinical ventricular tachycardias were induced six times (16%). In one patient clinical ventricular tachycardia was observed. In seven instances (19%) sinus rhythm remained. In 12 of the 13 patients, ventricular fibrillation could be induced by DC. Thus, the induction of ventricular fibrillation by DC application may serve as an additional tool to induce ventricular fibrillation, determining the defibrillation threshold in implantable cardioverter defibrillator patients.

Cardiac Catheterization↗
PubMed1992

Value of Holter monitoring in patients with the long QT syndrome.

The idiopathic long QT syndrome (LQTS) is an infrequently occurring disorder. It has major clinical impact as patients are prone to syncope, ventricular tachyarrhythmias and sudden arrhythmogenic cardiac death. This paper reports the value of ambulatory electrocardiogram (ECG) monitoring as a diagnostic tool to establish the diagnosis of LQTS. 14 patient with idiopathic LQTS were studied. The results were compared to those of 14 age- and sex-matched healthy control individuals. A 24-hour ambulatory ECG tracing was obtained in each individual. 5/14 patients with LQTS had pathological findings during ambulatory ECG monitoring (2 patients with episodes of torsade de pointes tachycardia, 2 patients with T-wave alternans and 1 patient with bradycardia due to an intermittent SA block), whereas all control persons had normal ambulatory ECG recordings (p < 0.03). Thus, ambulatory ECG recordings may contribute significant diagnostic information in patients with suspected LQTS.

Adolescent↗
PubMed1992

Association between rheology and components of lipoproteins in human blood. Results from the MONICA project.

BACKGROUND: Recent studies have suggested that several hemostatic factors, leukocyte count, and plasma viscosity are predictive of coronary heart disease. Detailed analyses on lifestyle correlates, in particular plasma lipids and lipoproteins, of determinants of blood rheology have not been reported from epidemiological studies. METHODS AND RESULTS: We studied the relation between determinants of blood rheology and components of lipoproteins in a large sample of a population aged 25-64 years. The rheological parameters investigated were plasma viscosity, hemoglobin, and total serum protein; the lipoprotein variables included total cholesterol, high density lipoprotein (HDL) cholesterol, and the apoproteins A-I, A-II, and B. Covariables considered for possible confounding effects were age, body mass index, smoking behavior, alcohol consumption, and hypertension. Plasma viscosity was found to have a positive linear association with total cholesterol and apoprotein B (partial correlations after adjustment for all covariables including total serum protein for men and women were r = 0.23/0.19 and 0.24/0.25, respectively) and a small negative linear association with HDL cholesterol (r = -0.14/-0.10) and with apoprotein A-I (r = -0.08/-0.06). Polynomial regression showed a strong quadratic relation with HDL cholesterol in men, whereas no other variable revealed an appreciable deviation from linearity. The covariables had only a small, if any, confounding effect. Total serum protein, after control for the covariables, appeared to be associated only with total cholesterol. No association was found with hemoglobin. CONCLUSIONS: We conclude that rheological mechanisms may be involved in the pathogenesis of ischemic syndromes in hyperlipidemias. However, the finding that in particular men with very low HDL cholesterol exhibit increased plasma viscosity cannot be explained in pure rheological terms but may be, at least in part, the result of concomitant hypertriglyceridemia. This was not assessed in this study.

Adult↗
PubMed1992

Blood rheology after LDL apheresis using dextran sulfate cellulose absorption--a case report.

The authors describe a thirty-eight-year-old woman with familial hypercholesterolemia treated by dextran sulfate cellulose adsorption apheresis. This technique and the selective extracorporeal LDL cholesterol elimination by immunoabsorption or heparin-induced precipitation not only dramatically decrease blood lipids but also result in a marked improvement in the rheologic profile. It is suggested that the amelioration of blood rheology by LDL apheresis may represent the cause for the early clinical improvement felt by most patients with severe coronary heart disease and hypercholesterolemia.

Adsorption↗
PubMed1992

Lovastatin alters blood rheology in primary hyperlipoproteinemia: dependence on lipoprotein(a)?

As part of a randomized, single-blind, comparative study evaluating the efficacy of lovastatin and bezafibrate retard in the treatment of primary hypercholesterolemia, hemorheologic parameters (whole blood viscosity, hematocrit, plasma viscosity, red blood cell aggregation and deformability, and fibrinogen) were studied in 35 patients. Whole blood viscosity and plasma viscosity improved significantly after 3 months of treatment with lovastatin, whereas other hemorheologic variables remained unchanged. Stratifying 24 patients by their lipoprotein Lp(a) levels showed that in those with low Lp(a) (less than or equal to 25 mg/dL) high-density lipoprotein cholesterol increased and red blood cell aggregation as well as deformability decreased considerably, whereas in the group with high Lp(a) levels (greater than 25 mg/dL), the opposite behavior was observed. Treatment of primary hypercholesterolemia with lovastatin may not only reduce the risk for atherosclerotic complications by its pronounced decrease of low-density lipoprotein cholesterol, but also may favorably alter blood rheology, and may decrease insudation of plasmatic components into the arterial wall and improve tissue perfusion, in particular on the microcirculatory level. The possible relevance of Lp(a) levels for the hemorheologic effects of lovastatin remains to be elucidated.

Bezafibrate↗