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Biomedical subjects

B Lemke

Publications and source records attributed to B Lemke.

At least 19 recordsLinked to original sources

Coronary artery stenting in diabetes mellitus--unfavourable clinical outcome due to increased rate of myocardial ischemia and percutaneous interventions.

Diabetes mellitus is one of the major risk factors for cardiovascular diseases. The aim of this study was to analyze if diabetic patients, compared to nondiabetic patients, have a worse angiographic and clinical success rate and a reduced clinical and angiographic outcome at three-months follow-up after coronary artery stenting according to postprocedural complications, recurrent angina, myocardial ischemia, restenosis and revascularization. A total of 307 unselected patients with coronary artery disease and myocardial ischemia who underwent intracoronary stenting were included in this study. Diabetes was present in 49 patients. Morphological criteria, angiographic results and clinical in-hospital outcome did not differ significantly between both groups. At follow-up diabetics presented significantly more often recurrent angina and myocardial ischemia. The rate of restenosis and target lesion revascularization was not different. Among diabetics, the rate of percutaneous coronary interventions because of different lesions was significantly increased. Diabetes does not reduce the angiographic result initially and at follow-up after coronary artery stenting. Diabetes mellitus limits the clinical outcome because of recurrent angina, myocardial ischemia and the need of coronary interventions.

Aged↗

Efficacy of an additional MAZE procedure using cooled-tip radiofrequency ablation in patients with chronic atrial fibrillation and mitral valve disease. A randomized, prospective trial.

AIMS: This study is the first prospective randomized trial evaluating the efficacy of an antiarrhythmic surgical procedure in patients with chronic atrial fibrillation undergoing mitral valve replacement. METHODS AND RESULTS: Thirty consecutive patients with chronic atrial fibrillation undergoing mitral valve replacement were randomized for an additional modified MAZE-operation using intra-operatively cooled-tip radiofrequency ablation (group A) or mitral valve replacement alone (group B). Biatrial contraction was studied and functional capacity was evaluated in spiro-ergometry 6 months after surgery. Thirty-day mortality was 0% in both groups. After 12 months, sinus rhythm was reinstituted significantly more often in patients of group A (cumulative rate of sinus rhythm 0.800) compared to patients in group B (0.267) (P<0.01). 66.7% of patients in sinus rhythm of group A had documented biatrial contraction. Electrocardioversion showed long-term success in only 17% of patients in group A and 0% in group B. Maximal aerobic uptake at the 6-month spiro-ergometry revealed no significant difference (9.3 vs 8.5 ml x min(-1) kg(-1), P=0.530). CONCLUSIONS: A modified MAZE operation using cooled-tip radiofrequency ablation can be safely combined with mitral valve surgery and is highly effective in restoring sinus rhythm. Biatrial contraction is found in 66.7% of patients with sinus rhythm undergoing mitral valve replacement plus the MAZE operation.

Aged↗

[Sensor-induced rate adaptation: sensor systems and tuning. Manual versus automatic tuning].

BACKGROUND: Rate adaptive stimulation represents an established therapeutic option in the management of cardiac rhythm disturbance. To realize a physiologic heart rate in patients with chronotopic incompetence several different sensor systems were developed. Due to the requirements of a physiologic pacemaker with all algorithms and therapeutic functions complex pacemaker systems were created. The realization of an automatic rate optimization was given by self adjusting algorithm or new sensor systems (closed loop systems). Comparing data respecting automatic vs manual sensor adjustment are not present. The automatic sensor adjustment was examined only in small patient groups. CONCLUSION: This studies indicated that most patients could be adjusted by the automatic function. Nevertheless, out of technical reasons a small group of patients could not be adjusted. The verification of the correct individual rate response in all patients treated with rate response pacemakers belongs to the physicians obligation.

Adult↗

[Minimally invasive percutaneous contrast-ultrasound guided thrombin occlusion of iatrogenic pseudoaneurysm].

BACKGROUND: Complicating femoral artery puncture aneurysms may occur resulting in the need for surgical or newer, non- or minimal-invasive therapy: A new minimal-invasive method is the percutaneous occlusion injecting bovine thrombin. The high thrombogenous potential of thrombin bears the risk of iatrogenic artery occlusion by artificial intravascular instillation. AIM: Is the contrast-ultrasound guided thrombin injection safe and effective in occluding femoral aneurysms? METHODS: During 1/99 to 12/00, 33 femoral artery aneurysms as a complication coronary catheterization were diagnosed. In 32 patients the aneurysm (mean dimensions 32 x 35 x 24 mm) was punctured during ultrasound guidance. By injecting ultrasound contrast medium, the flow pattern perfusing the aneurysm was documented. In the canula position where no contrast medium exited the aneurysm thrombin was injected. RESULTS: Complete occlusion of the aneurysm was achieved in 96.9% (31 out of 32) of the patients by contrast-ultrasound guided thrombin occlusion. Follow-up for up to 3 months after the procedure revealed complete occlusion and no clinical or sonographical complications. In one case, a large aneurysm (50 mm x 62 mm x 27 mm) had already led to skin alterations and was only partly occluded by thrombin injection. CONCLUSIONS: Contrast-ultrasound guided thrombin occlusion of femoral artery aneurysms is safe and highly effective.

Aneurysm, False↗

Saline-irrigated, cooled-tip radiofrequency ablation is an effective technique to perform the maze procedure.

BACKGROUND: We evaluated the effectiveness of the saline-irrigated-cooled-tip-radiofrequency ablation (SICTRA) to produce linear intraatrial lesions. METHODS: Thirty patients with chronic atrial fibrillation and mitral valve disease were consecutively randomized to have mitral valve operation either with a Maze procedure (group A) or without (group B). Intraatrial linear lesions were made with an SICTRA catheter (20 to 32 W; 200 to 320 mL/h saline). An echocardiography and 24-hour electrocardiogram were obtained 12 months postoperatively. RESULTS: The cumulative frequencies of sinus rhythm in group A and B were 0.80 and 0.27 (p < 0.01). Restored biatrial contraction was present in 66.7% (6 of 9) of the group A patients in sinus rhythm. One patient from each group received a permanent pacemaker because of bradycardia. A fatal renal bleeding and mediastinitis occurred in 2 group A patients, 6 weeks postoperatively. One group A patient had sudden cardiac death at home, 4 months after operation. One patient from each group had lethal respiratory failure, 7 and 10 months after operation. Survival after 12 months for group A and B was 73% and 93% (p = 0.131). CONCLUSIONS: The SICTRA appeared to be an effective technique to perform the Maze procedure.

Aged↗

Prevalence, characteristics and clinical implications of regular atrial tachyarrhythmias in patients with atrial fibrillation: insights from a study using a new implantable device.

OBJECTIVES: This study prospectively analyzed atrial tachyarrhythmia (AT) organization and antitachycardia pacing (ATP) success in patients with an implanted device for AT therapy. BACKGROUND: In patients with atrial fibrillation (AF), the incidence of regular, slow ATs amendable by ATP is unknown. METHODS: Forty patients with previously documented AT (70% with AF) received a new pacemaker with atrial electrogram (AEG) storage and atrial ATP capabilities for standard pacing indications. The AEGs acquired during the first month (study phase 1) were classified into high (type I), intermediate (type II) and low (type III) degrees of organization. Atrial ATP was then activated, and treated AT episodes were retrieved three and six months after implantation (study phase 2). RESULTS: Of 824 AEGs retrieved before ATP activation (study phase 1), 351 (43%) were classified as type 1, 47% as type II and 10% as type III. Episodes of AT starting as type I (35%) and type II or III (65%) maintained their type over 1 min in 73%. All patients with an exclusive history of AF also showed type I AEGs. In 361 subsequently treated AT episodes (study phase 2), ATP was successful in 62% of type I and 34% of type II episodes, but not in type III (p < 0.0001). CONCLUSIONS: The majority of patients with a history of AF show not only disorganized but also highly organized AT episodes, which can be successfully terminated by ATP.

Aged↗

[Expectations and satisfaction of patients during inpatient treatment].

PURPOSE: Aim of the study was to examine the expectations of patients at the beginning and the satisfaction at the end of a hospital stay. The hospital settings were standardised. METHODS: 510 patients on the cardiological ward were asked to fill in a questionnaire on the first and last day of their stay. RESULTS: The admitted patients stated clear expectations in respect of the hospital facilities and staff. The most important aspects for the patients were the qualification of staff and the time physicians and nurses would devote to the patient, and the medical and technical equipment of the hospital. Beds per room, food, length and costs of the stay were less important in patients' expectations. On the day of discharge, the patients were very satisfied with the staff and medical equipment, in contrast to a low satisfaction regarding additional fees and the number of beds per room (three). CONCLUSIONS: Since cost-benefit is a basic need in running a hospital today, financial resources should be enhanced in the spheres which are equally medically important for fulfilling the expectations of the patients. Therefore, the number of staff and the qualification of the medical professionals should be financed instead of supporting architectural and room design. Accordingly, the patients' main criteria for choosing a hospital is the medical equipment provided and the qualification of the medical staff. In conclusion, these aspects should be publicized for meaningful decision-making. Medical professionals should be encouraged to inspire competence and to spend as much time as possible with each individual patient.

Adolescent↗

Functional variables associated with the clinical grade of dyspnoea in coal miners with pneumoconiosis and mild bronchial obstruction.

OBJECTIVES: Dyspnoea is a common symptom in coal miners with pneumoconiosis. Among others, gas exchange disturbances due to airway obstruction or mismatch between ventilation and perfusion may be underlying mechanisms. The validation of dyspnoea by the degree of airway obstruction is controversial, because the extent of airway obstruction often does not correlate with the clinical grade of breathlessness. METHODS: The association was investigated between breathlessness (self reported, on a six point scale) and indices of submaximal spiroergometry in 66 coal workers with radiographically confirmed pneumoconiosis (International Labour Organisation (ILO) grade of profusion > or =1/0, mean (SD) age 64 (5.5) years, mean (SD) forced expired volume in 1 second (FEV(1)) 77.5 (22.9) % predicted). RESULTS: The clinical degree of breathlessness was independently associated with minute ventilation/oxygen consumption (VE/VO(2)) ratio (beta 0.423, 95% confidence interval (95% CI) 0.18 to 0.67, p=0.001) and smoking (beta 0.318, 95% CI 0.21 to 1.79, p=0.014) in a multiple linear regression analysis. The VE/VO(2) ratio (beta 0.556, 95% CI 0.20 to 0.90, p=0.003) was also the best predictor of breathlessness when only coal miners with airway obstruction (FEV(1) < 80% predicted) were analyzed. CONCLUSION: The VE/VO(2) ratio as a measurement of mismatch between ventilation and perfusion predicted the clinical grade of breathlessness better than measurements of bronchial obstruction at rest in coal workers with pneumoconiosis.

Aged↗

Efficacy and safety of ticlopidine monotherapy versus ticlopidine and aspirin after coronary artery stenting: follow-up results of a randomized study.

A combined antiplatelet treatment with ticlopidine and aspirin has been accepted as standard pharmacological regimen after coronary artery stenting. No data of a randomized trial are available on ticlopidine monotherapy. This prospective, randomized monocenter trial investigates the role of ticlopidine monotherapy versus combined antiplatelet therapy with ticlopidine and aspirin in unselected patients undergoing coronary artery stenting. After successful placement of 378 coronary artery stents, two hundred and forty-three consecutive patients were randomly assigned to receive antiplatelet therapy with 2 x 250 mg ticlopidine (121 patients) or a combination of 2 x 250 mg ticlopidine plus 100 mg aspirin (122 patients) daily. The primary endpoint included the absence of death, cardiac events and vascular access-site complications during the in-hospital phase. Angiographic and clinical assessment was repeated at the 3-month follow-up exam. Two hundred and thirty-seven patients (97.5%) were free from cardiac and non-cardiac events. Stent thromboses were seen in 2 patients of the combined treatment group, while none were observed in the monotherapy group. No statistically significant differences were found between the 2 groups regarding the primary endpoint. Angiography performed in 210 patients (86.4%) at follow-up revealed a restenosis rate of 29.4% in the combined treatment group and 27.8% in the monotherapy group. Monotherapy with ticlopidine is as safe and effective as a combined regimen of ticlopidine plus aspirin after coronary artery stenting in an unselected patient population. These results need to be confirmed in a larger multicenter trial.

Aged↗

[Health promotion and cardiovascular risk factors. The level of knowledge among 510 inpatients of an acute coronary care unit].

PATIENTS AND METHODS: A total of 510 patients hospitalized on a cardiologic ward were questioned on cardiovascular disease risk factors using a questionnaire. The knowledge on these risk factors was assessed with a score system. RESULTS: Knowledge of patients on cardiovascular disease risk factors was generally low: One out of 5 did not know about the consequences of obesity, high blood cholesterol or smoking on the coronary vessels. Over 30% did not name hypertension. Only 1 out of 3 patients mentioned diabetes mellitus as a risk factor. There was no change in the knowledge during the hospital stay despite a standardized and intensive information program. The results of the second survey on the day of discharge were equal to the results of the admission day. Hospital stays in the past had no influence on the knowledge. Patients with a diagnosed coronary heart disease had the same results in the survey as patients with other diseases. The presence of risk factors had hardly any influence on the knowledge of these patients. CONCLUSION: The result of this study emphasizes the need for better health information for patients. The repetitive information on health related issues during inpatient treatment does not seem to have a positive effect on patients' knowledge. Therefore other ways of health education have to be introduced and evaluated in acute care.

Adult↗

Characterization of muscle filamin isoforms suggests a possible role of gamma-filamin/ABP-L in sarcomeric Z-disc formation.

Filamin, also called actin binding protein-280, is a dimeric protein that cross-links actin filaments in the cortical cytoplasm. In addition to this ubiquitously expressed isoform (FLN1), a second isoform (ABP-L/gamma-filamin) was recently identified that is highly expressed in mammalian striated muscles. A monoclonal antibody was developed, that enabled us to identify filamin as a Z-disc protein in mammalian striated muscles by immunocytochemistry and immunoelectron microscopy. In addition, filamin was identified as a component of intercalated discs in mammalian cardiac muscle and of myotendinous junctions in skeletal muscle. Northern and Western blots showed that both, ABP-L/gamma-filamin mRNA and protein, are absent from proliferating cultured human skeletal muscle cells. This muscle specific filamin isoform is, however, up-regulated immediately after the induction of differentiation. In cultured myotubes, ABP-L/gamma-filamin localises in Z-discs already at the first stages of Z-disc formation, suggesting that ABP-L/gamma-filamin might play a role in Z-disc assembly.

3T3 Cells↗

Hyperfibrinogenemia increases the risk of cardiac events after coronary artery stenting.

Primary success rates, and the angiographic and clinical outcome after percutaneous coronary intervention, are influenced by many different factors. Clinical features and morphologic characteristics of the target lesion are important. Also, interventionally caused endothelial trauma may trigger atherogenetic and procoagulatory factors leading to intraluminal thrombosis. The study population consisted of 228 consecutive, unselected patients with symptomatic coronary artery disease or exercise-induced myocardial ischemia and coronary artery stenoses eligible for percutaneous intervention. We analyzed different clinical, morphological, and laboratory (total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, triglycerides, fibrinogen) features in those patients with adverse cardiac events (stent thrombosis, myocardial infarction, urgent target vessel revascularization, death) after primary successful coronary artery stenting, compared with a control group without adverse events. In the group with adverse cardiac events we found a significantly higher level of fibrinogen compared with the control group. Other laboratory data and clinical characteristics were not significantly different between the two groups. The study shows a possible association between hyperfibrinogenemia and adverse cardiac events after intracoronary stenting. In clinical practice, the potential role of elevated levels of fibrinogen in an unfavorable outcome after percutaneous coronary interventions should be considered when planning coronary artery stenting.

Aged↗

Atrial pacing in the prevention of paroxysmal atrial fibrillation: first results of a new combined algorithm.

UNLABELLED: Pacing algorithms for prevention of atrial tachyarrhythmia (AT) are under clinical evaluation. The present study prospectively evaluated the efficacy of three simultaneously active algorithms for AT prevention and aimed at identifying patients in whom atrial preventive pacing (APP) may be particularly successful. METHODS: In 31 patients with conventional pacing indications and paroxysmal AT, a DDDRP pacing system was implanted, which stores 35 AT episodes with atrial electrograms and marker annotations. Counters and stored AT episodes were retrieved 30 days after implant. APP algorithms (atrial preference pacing, atrial rate stabilization, postmode switching overdrive) were activated. Counters and stored AT episodes were again retrieved 60 days later. The number and duration of AT episodes was measured. Several clinical variables were examined with respect to their ability to identify candidates for APP. RESULTS: During APP, the mean number of AT episodes/patient/day decreased from 7.67 to 1.68 (P = 0.04). However, time in AT was not significantly reduced (9.45% versus 10.41%). APP decreased the number of episodes/day in 11 patients and increased it in 9 patients. No clinical parameters predicting APP success was identified. CONCLUSIONS: APP using three algorithms significantly reduced the mean number of AT episodes/patient/day. However, the time during which patients were in AT was not reduced. No clinical variable predicted the success or failure of APP.

Aged↗

Comparison of the efficacy and safety of aspirin alone with coumadin plus aspirin after provisional coronary stenting: final and follow-up results of a randomized study.

BACKGROUND: The antithrombotic benefit of the conventional treatment with coumadin after coronary stenting is limited by bleeding complications. However, the superiority of an antiplatelet therapy with aspirin alone compared with coumadin plus aspirin has not been proven by randomized studies. The efficacy and safety of treatment with aspirin alone in comparison to coumadin plus aspirin were evaluated in this randomized study. METHODS: Out of 164 patients aged 59.7 +/- 9.2 years, 79 patients were randomly assigned to receive 100 mg aspirin daily (group A) and 85 patients randomly assigned to coumadin plus aspirin (group CA) after provisional coronary stenting with a high-pressure technique. The primary end point was defined as the absence of death, subacute closure of the target vessel, myocardial infarction, urgent coronary bypass surgery, repeated coronary angioplasty, and peripheral vascular complications requiring transfusion or surgery. High-pressure inflation technique was used, but ultrasound guidance was not. RESULTS: During hospitalization (median 8 days), 135 patients (82. 3%) were free of events (A, 84.8%; CA, 80.8%; P =.42). Eleven (6.7%) subacute closures occurred (A, 10.1%; CA, 3.5%; P =.09); 2 of them were lethal in the aspirin group. Emergency bypass surgery was performed in 1 patient in each group. Peripheral vascular complications were observed in 13 patients (7.9%) (A, 1.3%; CA, 14. 1%; P <.01). At 3-month follow-up, 15 (9.1%) elective revascularization procedures (A, 7.6%; CA, 10.6%; P =.51) were performed. CONCLUSION: Aspirin alone at the low dose of 100 mg administered or the combination of coumadin and aspirin after high-pressure coronary stenting does not prevent adverse clinical events when ultrasound guidance is not used.

Angioplasty, Balloon, Coronary↗

Restoration of cardio-circulatory regulation by rate-adaptive pacemaker systems: the bioengineering view of a clinical problem.

In the past, the development of rate-adaptive (sensor-controlled) pacemaker systems seems to have been determined primarily by the availability, compatibility and other properties of the technical sensor. This paper, however, focuses on the system-physiological aspect in an attempt to answer the question to what extent physiological cardiovascular control is restored by the pacemaker system. This is a question which should be asked before attempting to design a sensor-controlled system and especially before designing multisensor systems with infinite combinations. Four categories are defined: direct bridging ("shunting"), open loop systems, closed systems using cardiorespiratory or metabolic coupling and those using cardiac signals. Further subdivisions are shown. From the bioengineering as well as from the physiological viewpoint a system should preferably not combine sensors from one and the same of these categories. At present direct bridging is available only for the atrioventricular (AV)-block, so that for sick-sinus-syndrome (SSS) patients feedback control via cardiac signals ("inotropic" pacemaker) comes nearest the goal without, however, ideally bridging the gap. Open-loop systems should no longer be developed as single-sensor systems. A well developed activity sensor, however, which quickly pinpoints the most prominent stressor of cardiovascular control is best suited to complement another sensory system achieving closed-loop control. New and promising concepts orientated toward direct bridging are the analysis of monophasic action potentials and the "dromotropic" concept, both of which seek direct correlation with the "chronotropic" information not available in SSS patients.

Adaptation, Physiological↗

Influence of the pacing rate on the atrioventricular conduction time during aerobic and anaerobic exercise: basic concepts for a dromotropically controlled rate responsive pacemaker.

The dromotropic pacemaker concept needs a rate responsive algorithm in which the pacing rate is controlled by the atrioventricular conduction time (AVCT). To develop basic concepts for such a rate responsive algorithm, the influence of the pacing rate on the AVCT was investigated. Seven patients (62 +/- 7.8 years) with sick sinus syndrome and intact atrioventricular conduction underwent two cardiopulmonary exercise tests (CPX) on a treadmill. According to the determination of the anaerobic threshold (AT) and the patients maximum capacity in the first incremental CPX the work rate for two exercise levels below and above the AT were chosen for the second constant workload CPX. The calculation of the optimal pacing rate (HRopt) was based on the oxygen uptake (VO2) during exercise after reaching steady-state conditions. According to the increase of the VO2 from 14.8 +/- 2.3 mL/min per kilogram during aerobic work (38.3 +/- 16.0 W) to 19.4 +/- 4.7 mL/min per kilogram during anaerobic work (80.6 +/- 32.3 W), the HRopt was calculated to be 98.6 +/- 6.9 beats/min and 116.4 +/- 4.7 beats/min. Starting from HRopt, the pacing rate was increased (overpacing) and decreased (underpacing) by about 5 beats/min every minute. At optimal pacing rate the AVCT decreased significantly from 233.0 +/- 30.5 ms during aerobic work and to 226.4 +/- 27.3 ms during anaerobic work (P < 0.05). Whereas overpacing induced a significant prolongation of the AVCT during aerobic work (4.17 +/- 1.78 ms per 10 beats/min) and anaerobic work (3.84 +/- 1.60 ms per 10 beats/min), underpacing yielded a significant shortening of the AVCT by about 4.49 +/- 2.64 ms per 10 beats/min during aerobic work and 4.75 +/- 1.87 ms per 10 beats/min during anaerobic work (P < 0.01). The slopes of the regression lines of the relationship between AVCT and pacing rate were not significantly. different. Based on the reciprocal relationship of heart rate (HR) and AVCT, basic concepts may be established for a dromotropic rate responsive algorithm.

Aged↗