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Berndt Lüderitz

Publications and source records attributed to Berndt Lüderitz.

At least 19 recordsLinked to original sources
PubMed2004

Incidence of venous obstruction following insertion of an implantable cardioverter defibrillator. A study of systematic contrast venography on patients presenting for their first elective ICD generator replacement.

AIMS: The number of implantable cardioverter defibrillator (ICD) implantations, as well as follow-up procedures such as generator exchanges, lead revisions and lead system upgrades, is ever-increasing. Lead revisions and implantation of additional leads require venous access at the site of the previous ICD implantation. The aim of our study was therefore to evaluate the incidence of venous obstruction after chronic transvenous ICD system implantation. METHODS AND RESULTS: One hundred and five consecutive patients admitted for their first elective ICD generator replacement were included. All patients underwent bilateral contrast venography and the images were analyzed by two attending radiologists. Venous obstruction was classified as moderate stenosis (50-75% diameter reduction), severe stenosis (>75%) or total occlusion. Venous obstruction of various degrees was found in 25% of the patients. Complete occlusion was found in 9%, severe stenosis in 6% and moderate stenosis in 10% of the patients. The incidence of venous obstruction was increased in patients with a pacemaker prior to the initial ICD system implantation (67%). No difference was found in patients with a single defibrillator lead compared with patients who had an additional superior vena cava (SVC) shocking coil. However, the presence of a second shocking coil in the SVC incorporated in a single ICD lead was associated with an increased incidence of venous obstruction. No difference was found between silicone and polyurethane insulated leads. CONCLUSION: This study shows that venous obstruction occurs relatively frequently after ICD implantation. Therefore, contrast venography should always be obtained if malfunction of a preexistent lead is suspected or a system upgrade is considered.

Brachiocephalic Veins↗
PubMed2003

Presence of bone-marrow- and neural-crest-derived cells in intimal hyperplasia at the time of clinical in-stent restenosis.

OBJECTIVE: Intralesional data of coronary target lesions following stent implantation are infrequent. In addition, there is ongoing controversy on the origin of neointimal cells. In this respect, several lines of evidence revealed bone-marrow-derived endothelial progenitor and dendritic cells (DCs) as well as neural-crest-derived cells (NCCs) to contribute to atherosclerosis. Therefore, the objective of the present study was to assess cellularity, cell type and origin of neointimal cells in in-stent restenosis (ISR). METHODS: Atherectomy specimens from 17 patients with coronary in-stent restenosis (n=10; time post-stenting 5+/-3 months) and with peripheral in-stent restenosis (n=7; 7+/-3 months) versus those from 10 patients with primary lesions were immunohistochemically examined for the presence of the determinants CD34, AC133, S100, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), nerve growth factor receptor (NGFR) and alpha-smooth muscle actin followed by computer-assisted morphometry. RESULTS: In-stent restenosis probes consistently demonstrated homogeneous hypercellularity (942+/-318 cells/mm(2)) compared to de novo lesions (347+/-120 cells/mm(2), P<0.001). alpha-smooth muscle actin positive cells occupied 67% of intimal cells in in-stent restenosis. As a key finding, expression of endothelial progenitor cells (CD34: 7.1+/-2.5% positive/total cells vs. 0.6+/-0.7%, P<0.001; AC133: 7.0+/-3.4% vs. 1.0+/-0.7%, P<0.001), dendritic cells (S100: 9.8+/-5.6% vs. 1.4+/-1.1%, P<0.001) and neural-crest-derived cells (GFAP: 7.9+/-2.4% vs. 3.1+/-1.0%; NSE: 4.4+/-2.6% vs. 1.3+/-1.6%; NGFR: 4.2+/-2.5% vs. 1.1+/-0.7%; each P<0.001) was significantly increased in in-stent restenosis compared to primary lesions. CONCLUSIONS: Bone-marrow- and neural-crest-derived cells, the most dendritic cells, are consistently present in in-stent restenosis, whereas alpha-smooth muscle actin positive cells constitute the largest intimal cell pool. Our data suggest the recruitment of primarily extravascular cells within neointima formation in human in-stent restenosis.

AC133 Antigen↗
PubMed2003

Influence of the point of origin on heart rate turbulence after stimulated ventricular and atrial premature beats.

BACKGROUND: Heart rate turbulence (HRT) is a new and auspicious parameter for risk stratification in patients suffering from structural heart disease. The HRT parameters onset (TO) and slope (TS) are derived from Holter ECGs. Only a few studies have evaluated physiologic properties like age or prematurity of the ventricular beat on HRT. Until now, to our knowledge, little is known about the influence of the point of origin of the premature beat on HRT. Therefore, we conducted a study consisting of 25 patients (pts) with premature beats generating from 2 different sites in the atrium and ventricle. METHODS: During an electrophysiologic study, premature extra beats were induced. The high right atrium (HRA) and the lateral part of the coronary sinus (CS) represented the atrial pacing sites, while the right ventricular apex (RVAP) and right ventricular out flow tract (RVOT) represented the ventricular pacing sites. Prematurity started at 450 ms and was decreased to the refractoriness of each site. TO and TS were computed and correlated to the site of origin and the coupling interval (CI). RESULTS: Atrial TO was positive in 9 pts (HRA) and 7 (CS) as well as ventricular TO in 2 pts, respectively. TO induced in CS correlated with the CI (r = -0.50, p < 0.05). TS was negative, independent of the site of origin. Atrial TS showed no correlation with the CI. TO generated from both ventricular sites was positive in 2 pts. TO from RVAP correlated with the CI (r = -0.81, p < 0.005), but not with RVOT. TS from both ventricular sites exhibited no correlation with the pacing site, but correlated with themselves (r = -0.69, p < 0.03). CONCLUSION: The site of origin of the premature beat exhibits no influence on heart rate turbulence slope. The prematurity of the extra beat correlates with turbulence onset, but not with slope. Finally, the site of origin revealed no influence on HRT slope. Therefore, the calculation of heart rate turbulence derived from extra beats extracted from Holter ECG is reliable.

Atrial Premature Complexes↗
PubMed2003

Dendritic cells in neointima formation after rat carotid balloon injury: coordinated expression withanti-apoptotic Bcl-2 and HSP47 in arterial repair.

OBJECTIVES: We sought to evaluate: 1) the contribution of dendritic cells (DCs); and 2) the impact of B-cell lymphoma 2 protein (Bcl-2), a central anti-apoptotic protooncogene, and of heat shock protein 47 (HSP47), indicating subsequent collagen deposition, in neointima formation after angioplasty. BACKGROUND: The origin of neointimal cells and the factors that promote their accumulation are still unclear. Previous studies reported intimal presence of DCs and suggested cells of primarily extravascular origin to contribute to arterial repair. METHODS: Sprague-Dawley rats underwent carotid balloon angioplasty. At different times after angioplasty, tissue sections were analyzed by immunohistochemistry using OX-62 and S100 as DC markers and antibodies against Bcl-2 and HSP47, supplemented by electron microscopic analysis of cell type and apoptosis. RESULTS: Four days after injury, DCs adhered along the internal elastic lamina and demonstrated intense Bcl-2 and HSP47 expression, consistent with low apoptosis. With ongoing neointima enlargement, luminal DCs remained prevalent and were colocalized with Bcl-2 and HSP47, while signaling decreased to basal regions. Media showed no DCs and only low Bcl-2 and HSP47 immunoreactivity. Adventitia transiently revealed a structural separation between day 4 and 7. Whereas the inner layer demonstrated sparse cellularity, apoptosis and no DC, Bcl-2, and HSP47 labeling, the outer layer was characterized by high myofibroblast density with strong Bcl-2 and HSP47 expression but absence of DCs. CONCLUSIONS: We identify DCs as novel components in early neointima formation, promoted by coordinated anti-apoptotic Bcl-2 and HSP47 expression. Despite intense adventitial remodeling, there is no evidence of adventitial cell transmigration.

Angioplasty, Balloon↗
PubMed2003

Silent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis: a prospective, randomised study.

BACKGROUND: In most patients, severity of valvular aortic stenosis can be accurately assessed non-invasively by echocardiography. However, retrograde catheterisation of the aortic valve is often undertaken. This procedure has a potential risk of neurological complications, with an unknown incidence of clinically silent embolism. We aimed to establish the frequency of clinically apparent and silent cerebral embolism after this procedure. METHODS: We prospectively randomised 152 consecutive patients with valvular aortic stenosis at a German university hospital to receive either cardiac catheterisation with (n=101) or without (n=51) passage through the aortic valve. Patients underwent cranial MRI and neurological assessment within 48 h before and after the procedure to assess cerebral embolism. Controls were 32 patients without valvular aortic stenosis who underwent coronary angiography and laevocardiography. FINDINGS: 22 of 101 patients (22%) who underwent retrograde catheterisation of the aortic valve had focal diffusion-imaging abnormalities in a pattern consistent with acute cerebral embolic events after the procedure; three of these patients (3%) had clinically apparent neurological deficits. By contrast, none of the patients without passage of the valve, or any of the controls, had evidence of cerebral embolism as assessed by MRI. INTERPRETATION: Patients with valvular aortic stenosis who undergo retrograde catheterisation of the aortic valve have a substantial risk of clinically apparent cerebral embolism, and frequently have silent ischaemic brain lesions. Patients should be informed about these risks, and this procedure should be used only in patients with unclear echocardiographical findings when additional information is necessary for clinical management.

Aortic Valve↗
PubMed2003

A. John Camm.

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Cardiology↗
PubMed2003

D-Ribose improves diastolic function and quality of life in congestive heart failure patients: a prospective feasibility study.

Patients with chronic coronary heart disease often suffer from congestive heart failure (CHF) despite multiple drug therapies. D-Ribose has been shown in animal models to improve cardiac energy metabolism and function following ischaemia. This was a prospective, double blind, randomized, crossover design study, to assess the effect of oral D-ribose supplementation on cardiac hemodynamics and quality of life in 15 patients with chronic coronary artery disease and CHF. The study consisted of two treatment periods of 3 weeks, during which either oral D-ribose or placebo was administered followed by a 1-week wash out period, and then administration of the other supplement. Assessment of myocardial functional parameters by echocardiography, quality of life using the SF-36 questionnaire and functional capacity using cycle ergometer testing was performed. The administration of D-ribose resulted in an enhancement of atrial contribution to left ventricular filling (40+/-11 vs. 45+/-9%, P=0.02), a smaller left atrial dimension (54+/-20 vs. 47+/-18 ml, P=0.02) and a shortened E wave deceleration (235+/-64 vs. 196+/-42, P=0.002) by echocardiography. Further, D-ribose also demonstrated a significant improvement of the patient's quality of life (417+/-118 vs. 467+/-128, P< or =0.01). In comparison, placebo did not result in any significant echocardiographic changes or in quality of life. This feasibility study in patients with coronary artery disease in CHF revealed the beneficial effects of D-ribose by improving diastolic functional parameters and enhancing quality of life.

Adenosine Triphosphate↗
PubMed2003

Quality of life evidence in the management of the individual patient with atrial fibrillation.

It is remarkable that in patients with paroxysmal AF not sufficiently controlled by pharmacological therapy, ablation and pacemaker treatment is highly effective and superior to drug therapy in controlling symptoms and improving quality of life. The discontinuation of drug therapy exposes patients to further recurrences of paroxysmal AF and the risk of developing permanent AF. However, both pharmacological and electrical treatment can enhance quality of life in AF patients. Long-term survival after ablation of the atrioventricular node and implantation of a permanent pacemaker in patients with AF is similar for AF patients whether they receive ablation or drug therapy; i.e. control of the ventricular rate by ablation of the atrioventricular node and permanent pacing do not adversely affect long-term survival.

Anti-Arrhythmia Agents↗
PubMed2003

Historical perspectives on interventional electrophysiology.

The history of interventional electrophysiology is long and fascinating. In the beginning, there is not simply the anatomy and physiology of the heart, but also analysis of the pulse, which indicates the activity of the heart. The analysis of the (peripheral) pulse as a mechanical expression of heart activity goes back several millennia. In China, in 280 B.C., Wang Chu Ho wrote ten books about the pulse. The Greeks called the pulse "sphygmos", and the sphygmology thus deals with a theory of this natural occurrence. In Roman times, Galen interpreted the various types of pulse according to the widespread presumption of the time, that each organ in every disease has its own form of pulse. The basic tool for arrhythmia diagnosis became the electrocardiography introduced by Willem Einthoven who obtained the first human electrogram 1902 in Leiden, The Netherlands. The growing clinical importance of electrical cardiac stimulation has been recognized and renewed as Zoll (1911-1999) in 1952 reported a successful resuscitation in cardiac standstill by external stimulation. Meanwhile all over the world, millions of patients with cardiac arrhythmias have been treated with pacemakers in the last 45 years. The concept of a fully automatic implantable cardioverter-defibrillator system (ICD) for recognition and treatment of ventricular tachyarrhythmias was first suggested in 1970. The first implantation of the device in a human being was performed in February 1980. Further developments concern atrial and atrioventricular defibrillators, radiofrequency ablation, laser therapy and advanced antiarrhythmic surgery, new antiarrhythmic drugs and sophisticated devices for preventive pacing. The advances in the field of diagnostic and therapeutic application of pharmacologic and electrical tools as well as alternative methods will continue as rapidly as before in order to give us further significant aid in taking care of the patient.

Arrhythmias, Cardiac↗
PubMed2003

Decremental pulmonary venous pulse propagation: impact for catheter ablation in focal atrial fibrillation.

BACKGROUND: Electrical isolation of pulmonary veins (PV's) is crucial to achieve success in catheter ablation for trigger elimination in focal atrial fibrillation (AF). To guide ostial PV radiofrequency (RF) delivery, it is necessary to identify the electrical breakthrough (EBT) between PV and left atrium. For this purpose, coronary sinus (CS) fixed rate pacing is commonly used. This study evaluated, whether CS extrastimulus pacing is superior in identifying the EBT area as compared to fixed rate pacing. METHODS: In 9 patients (51 +/- 10 years) undergoing a left sided electrophysiological study for AF ablation, 25 PV's (10 right and 15 left-sided PV's) were mapped using a 4 French fixed-wire catheter with eight 6 mm coiled Platinum electrodes in a distal looped configuration (Revelation Helix, Cardima Inc.). For mapping and ablation the electrode loop was positioned in the PV ostium rectangular to the longitudinal PV axis. EBT area was identified as those electrodes indicating the earliest PV signals during CS pacing. We measured number of EBT electrodes and time between EBT and the latest activated bipoles at the electrode loop during fixed rate and extrastimulus pacing. The reduction of two or more EBT electrodes was defined as a significant benefit in EBT identification. RESULTS: In 22 of 25 PV's mapped PV potentials could be observed. Performing fixed rate pacing the EBT area was identified in a mean of 4.2 +/- 1 electrodes, whereas using extrastimulus pacing, EBT area could be significantly reduced to 2.3 +/- 0.8 electrodes. The time between EBT and latest electrode activated increased from 14 +/- 7 ms to 22 +/- 10 ms indicating an intrapulmonary conduction delay during extrastimulus pacing. In 13 of 22 PV's mapped (59%), extrastimulus pacing was beneficial in the identification of the EBT, as the primary target for RF delivery. CONCLUSIONS: CS extrastimulus pacing induces intra-PV decremental conduction properties allowing one to identify a more localised and smaller EBT area as the primary target for RF delivery. Performing PV ablation to treat focal AF, extrastimulus maneuvers allow to unmask the "true" EBT and thus may help to limit intrapulmonary RF delivery.

Adult↗
PubMed2003

Naxos disease.

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Arrhythmogenic Right Ventricular Dysplasia↗
PubMed2003

Advanced pacemaker diagnostic features in the characterization of atrial fibrillation: impact on preventive pacing algorithms.

Pacing algorithms to prevent PAF are mainly based on the suppression of premature atrial complexes (PACs), which play an important role in its initiation. In contrast to 24-hour ambulatory electrocardiograms, advanced pacemaker (PM) diagnostic features are capable of recording AF episodes during long follow-up periods and of characterizing AF in a detailed fashion. For the specific use of these algorithms, a detailed characterization of AF was performed in 91 dual chamber PM recipients with histories of AF. Fifteen patients with episodes of oversensing due to far-field signals or frequent episodes of "2:1-undersensing" of atrial flutter were excluded. The remaining 76 patients had high recurrence rates of AF (median 0.8 episodes/day), however, the majority of episodes lasted < 7 minutes. Despite frequent PACs (median 10.8/hour) during sinus rhythm, a median of 66.4% of the AF episodes were preceded by < 2 PACs/min before onset. In conclusion, frequent, short-lived AF episodes seem best suited for AF preventive pacing therapies. However, the small number of PACs preceding many AF episodes may limit the efficacy of PAC suppressing algorithms.

Algorithms↗
PubMed2003

Incidence and rate characteristics of atrial tachyarrhythmias in patients with a dual chamber defibrillator.

Atrial tachyarrhythmias play an important role in the treatment of patients with malignant ventricular tachyarrhythmias not only with respect to inappropriate discharges but also to left ventricular function and stroke risk. A combined dual chamber defibrillator provides separate therapies for atrial and ventricular tachyarrhythmias. To assess the incidence of atrial tachyarrhythmias in patients with this dual chamber implantable defibrillator, 40 patients with ventricular tachyarrhythmias and concomitant atrial tachyarrhythmias and/or AV conduction disturbances were included in a prospective study. During a mean follow-up of 25 +/- 11 months, 26 of 40 patients had a total of 1,430 recurrences of atrial tachyarrhythmias. The vast majority of the atrial tachyarrhythmias with regular atrial cycles had a mean median atrial cycle length of 235 +/- 37 ms and a mean duration of 34 +/- 144 minutes. Atrial tachyarrhythmias with irregular atrial cycles exhibited a median atrial cycle length of 198 +/- 31 ms and had a mean duration of 246 +/- 1,264 minutes. In addition, 67% of 375 tachyarrhythmias, in which the median ventricular cycle length during the ongoing episode could be documented, had a ventricular rate <100 beats/min. Continuous atrial arrhythmia detection with a dual chamber ICD reveals a high incidence of atrial tachyarrhythmias with a predominantly short duration of paroxysmal recurrences <1 hour in the vast majority of episodes.

Algorithms↗
PubMed2003

Mechanical occlusion of the left atrial appendage.

INTRODUCTION: Oral anticoagulation therapy reduces significantly the risk of thromboembolism in patients with atrial fibrillation. However, effective oral anticoagulation therapy is not feasible in all patients. The interventional occlusion of the left atrial appendage may reduce the risk of thromboembolism in the latter patients. The aim of this prospective study was to assess the feasibility, safety, and technical aspects of interventionally occluding the left atrial appendage. METHODS AND RESULTS: The left atrial appendage was interventionally occluded with the new PLAATO device in nine patients. Serial transthoracic and transesophageal echocardiographic studies and neurologic assessment were performed prior to and during the procedure, and <48 hours, 3 months, 6 months, and 1 year after the procedure. Contraindications to oral anticoagulation were bleeding complications in 6 of 9 cases, cerebral aneurysm in 1, and allergies to warfarin therapy in 2 of 9. Baseline echocardiographic studies demonstrated spontaneous echo contrast grade 3 +/- 1, peak emptying velocities of 0.26 +/- 0.12 m/sec, and excluded atrial thrombi in all cases. Interventional occlusion was feasible in all cases. One patient had a minor plexus paresis that resolved within 4 weeks after the procedure. Neurologic assessment during a mean follow-up of 5 +/- 4.4 months did not demonstrate any new neurologic complications. Serial echocardiographic assessment excluded the formation of thrombi on the implanted device and demonstrated its complete thrombosis after 6 months. One patient developed a minimal pericardial effusion 48 hours after the procedure that resolved within 3 months. CONCLUSION: Interventional occlusion of the left atrial appendage is feasible and safe in patients with atrial fibrillation and contraindications to oral anticoagulation therapy. Furthermore, no neurologic complications, development of atrial thrombi, or thrombus formation on the device were observed during follow-up. Future prospective studies are needed to clarify the long-term treatment effect of this new technique.

Anti-Arrhythmia Agents↗