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Biomedical subjects

G Breithardt

Publications and source records attributed to G Breithardt.

At least 181 records · Page 10Linked to original sources
PubMed1997

[Acute thoracic aortic dissection with occlusion of the left coronary artery].

Aortic dissection is the most common fatal condition that involves the aorta. Occasionally, symptoms mimic acute myocardial infarction leading to thrombolytic treatment. Accurate diagnosis in patients with chest pain is therefore essential. We describe a case of acute aortic dissection which resulted in myocardial infarction due to obstruction of the left coronary ostium. A 65-year-old female patient with no previous cardiac history was admitted to a local hospital because of severe chest pain of acute onset. Physical examination was normal except for a low blood pressure (90/50 mm Hg), heart rate 45 beats/min and parasthesia in both hands. The ECG showed sinus bradycardia with negative T-wave in VI and with 1 mm ST-segment elevation in V3. A chest X-ray was normal. Five hours later, the patient experienced once more severe chest pain followed by non-sustained polymorphic ventricular tachycardia (Figure 1). Another ECG showed bifascicular bundle branch block (right bundle branch block and left anterior fascicular block). The ECG was interpreted as showing acute myocardial infarction and treatment with intravenous streptokinase started. Since the patient remained severely hypotensive despite infusion of dobutamine, she was intubated, ventilated and transferred to our hospital. Cardiac catheterization showed acute dissection of the ascending aorta with an aortic intimal flap and an occlusion of the left coronary artery (Figures 2a and b). During catheterization, she suffered a cardiac arrest from which she could not be resuscitated. A postmortem examination confirmed the acute aortic dissection which reached to the ostium of the left coronary artery (Figures 3a and b, 4a and b) and an anterior myocardial infarction probably due to intermitted diastolic obstruction of the ostium of the left coronary artery by an aortic intimal flap.

Aged↗
PubMed1997

[Evaluation of secondary prevention of coronary heart disease. Results of the EUROSPIRE study in the Munster region].

BACKGROUND: New recommendations for secondary prevention of coronary heart disease (CHD) were issued by the European Society of Cardiology (ESC), the European Atherosclerosis Society (EAS) and the European Society of Hypertension (ESH) in 1994. The main objective of the EUROASPIRE study (European Action on Secondary Prevention by Intervention to Reduce Events) was to evaluate to what degree the new recommendations have been implemented and whether a significant risk factor reduction in patients who presented with CHD has been achieved. The present study was conducted in the region of Münster, Westphalia, Germany, as part of the nine-country EUROASPIRE study. METHODS: A total of 524 patients (58.6 +/- 8.2 years) were included in the study by abstracting data from their medical records. According to the clinical event which led to admission to the hospital, patients belonged to the following four groups: 1) coronary artery bypass graft (CABG), 2) percutaneous transluminal coronary angioplasty (PTCA), 3) acute myocardial infarction, 4) acute myocardial ischemia. Initially, a pre-specified number of patients had been recruited with the goal of having 100 patients in each of the four groups participate in the follow-up interview and examination. At least 6 months and, on average, 20 months after hospital discharge for the acute event, 74.8% of the patients came to an interview and examination for an evaluation of their risk profile. RESULTS: At the interview, 15.6% of the patients smoked, 22.7% were obese, 54.6% had blood pressure levels above 140/90 mm Hg and 31.3% a total cholesterol/HDL-cholesterol-ratio greater than 5. Risk factor modification over time was insufficient as only one-fifth of patients had values of their risk factors within the target range at the time of the interview. CONCLUSION: The goals of secondary prevention have not been achieved in the region of Münster-there is clearly room for improvement. Considering the treatment of patients with CHD, the recommended strategies of secondary prevention need to be applied more intensively in clinical practice.

Adult↗
PubMed1997

[Results of testing defibrillator function of implanted cardioverter/defibrillators].

Postoperative tests of implantable cardioverter defibrillators (ICDs) are routinely performed to ensure appropriate defibrillation by the device. However, efficacy and complications of this procedure are unknown. To scrutinize the currently accepted indications to test the defibrillation function of the ICD we retrospectively analyzed 844 ICD-tests in 439 ICD-systems and 409 patients. 755 ICD-tests (89.4%) were routinely performed (57% before discharge and 43% during follow-up); 58 tests (6.9%) were performed after a change of the antiarrhythmic drug regimen, 24 tests (2.9%) after a revision of a part of the ICD-system, and seven tests (0.8%) because of a suspected dysfunction of the ICD. During routine-tests six ICD-systems (0.8%) failed to defibrillate the patient. However, in all but one test abnormalities of the ICD-system had been observed before the test. After addition of antiarrhythmic drugs, three of 58 ICD-systems (5.2%) failed to defibrillate the patient during the test (amiodarone: n = 2, flecainide: n = 1). Four of seven ICD-systems (57%) tested due to a suspected dysfunction failed to defibrillate the patient. After revisions of parts of the ICD-systems, ICD-tests never revealed a failure of defibrillation. During 16 ICD-tests (1.9%) complications occurred. The most frequent complications was inappropriate shocks (n = 10; 1.2%), the most severe one (transient) neurologic symptoms (n = 4; 0.48%). Our experience demonstrates that postoperative tests of the defibrillation function of ICDs rarely reveal ICD-dysfunction. As testing is unpleasant for the patient and not free of complications, tests might be restricted to those patients in whom an ICD-dysfunction is suspected (based on clinical presentation, results of chest-x-ray, testing of sensing signal and stimulation threshold) or class I or class III antiarrhythmic drugs have been added to the antiarrhythmic drug regimen.

Adolescent↗
PubMed1997

[Quality of life after implantation of a cardioverter-defibrillator (ICD)--results of an empirical study of 132 ICD patients].

All 181 patients with malignant arrhythmias who have been provided with an implantable cardioverter-defibrillator (ICD) at the University Clinics of Muenster during the last 3 years, were investigated by a clinical questionnaire on quality of life (QOL). 132 patients answered and could be included in the study (response rate 73%). The mean age of the patients was 55 +/- 11.8 years, 73% males, 60% had already retired. In the general view 51% of the patients reported fair to excellent quality of life, while 24% gave a negative description of their QOL. 26% of the patients suffered from side-effects of the treatment, primarily from unspecific psychological complaints and ICD-related disturbances. "Unrest" was the predominant psychological complaint (64% of the patients), followed by rumification, shortness of breath, weakness and sleep disturbances. Somatic function and sex life were the functional areas primarily affected (more than half of the patients complaining about these). The "Psychological General Well-Being Index (PGWB)" showed reduced well-being in 61% of the patients. Comparing with the literature and regarding the PGWB-scales well-being, anxiety, and depression no significant differences could be found in comparison with other cardiologic samples after bypass-surgery or valve replacement. The results indicate the need of individual counseling and offers of psychosocial support for this highly strained group to reduce anxiety and to improve the quality of life in order to help the patient to gain greater overall benefit from the new ICD-therapy.

Activities of Daily Living↗
PubMed1997

[Pregnancy in patients with transposition of great vessels corrected by the Mustard procedure. Report of a case and review of reported cases].

BACKGROUND: In patients after atrial switch operation (Mustard or Senning procedure) for transposition of the great arteries (TGA), the anatomic right (anterior) ventricle works as the systemic ventricle. Although this is associated with an increased rate of congestive heart failure, the prognosis for long-term survival is good. Therefore a large proportion of these patients has reached their reproductive years and consult cardiologists and obstetricians because they plan a pregnancy or are already pregnant. Because of the substantial hemodynamic changes and the increase in cardiac output during pregnancy, potential risk factors and complications have to be considered. PATIENTS: Initiated by the presentation of a pregnant patient with TGA after surgery in our hospital, we analyzed the information referenced in MEDLINE. Including our patient, there were reports on 27 patients after the Mustard procedure with a total of 39 pregnancies. FETAL OUTCOME: Three abortions occurred during the first trimenon, another one was electively induced because of maternal cardiac deterioration. One late abortion occurred in the 23rd week of pregnancy. 35 babies (one twinpair) were born healthy without cardiovascular anomalies. MATERIAL OUTCOME: No maternal deaths occurred. Eight women developed clinical signs of systemic (= right) heart failure including all three patients with former complex TGA. Four of these patients recovered after delivery, four showed persistent reduction of physical abilities or signs of heart failure. Further complications were supraventricular tachycardias (five patients) and a high incidence of hypertension and pre-eclampsia (22% of patients). CONCLUSION: Overall, the outcome for mothers after Mustard procedure for TGA and their children is good, but there is need for intensive and specialized follow-up.

Adult↗
PubMed1997

Autosomal recessive long-QT syndrome (Jervell Lange-Nielsen syndrome) is genetically heterogeneous.

Jervell Lange-Nielsen syndrome (JLNS) is a recessive disorder with congenital deafness and long-QT syndrome (LQTS 1). Mutations in the potassium-channel gene KVLQT1 (LQTS 1) have been identified in JLNS and in autosomal-dominant LQTS as well. We performed haplotype analysis with microsatellite markers in a Lebanese family with JLNS, but failed to detect linkage at LQTS 1. Moreover, using this approach, we excluded two other ion-channel genes involved in autosomal-dominant LQTS, HERG (LQTS 2) and SCN5A (LQTS 3). Our findings indicate that JLNS is genetically heterogeneous and that, in this family, an unknown LQTS gene causes the disease.

Cation Transport Proteins↗
PubMed1997

Copper-induced inflammatory reactions of rat carotid arteries mimic restenosis/arteriosclerosis-like neointima formation.

The pathogenesis of arteriosclerosis and of restenosis after angioplasty is linked with an inflammatory and fibroproliferative response of the arterial tissue. We have induced a non-infectious inflammation by implanting a silicon-copper cuff around rat carotid arteries. The copper ions released from the oxidized copper initiate and mimic all morphological features of post-angioplasty restenotic and arteriosclerotic lesions. The copper-induced lesions were analyzed by electron and light microscopy, immunohistochemical methods and quantified by morphometry. During the first phase of copper-induced tissue reaction (3 days), macrophages and polymorphonuclear leucocytes invaded through the endothelium, accumulated in the subendothelial space and triggered the proliferation of smooth muscle cells which then migrated from the tunica media through the lamina elastica interna into the intima. Within 3 weeks, the accumulated smooth muscle cells, macrophages, leucocytes and newly synthesized extracellular matrix formed a circular mostly eccentric fibrotic thickening that narrows the vessel lumen by 30-40%. The accompanying structural disorganization of the medial layer led to focal rupture and aneurysm-like dilatation of the vessel wall in 3 of 11 animals between day 20 and 43. The neointima progressively increased in thickness over time leading to corresponding reduction of the vessel lumen. The carotid arteries of control animals and animals treated with copper-free silicon cuffs showed no abnormal pathological appearance. Our results show that inflammation-inducing agents can contribute to and simulate restenosis- and arteriosclerosis-like lesions and that the copper-cuff model may be useful in the exploration of new approaches to intervention.

Angioplasty, Balloon↗
PubMed1997

Efficacy and safety of d,l-sotalol in patients with ventricular tachycardia and in survivors of cardiac arrest.

OBJECTIVE: The aim of this study was to assess the antiarrhythmic efficacy and safety of d,l-sotalol in patients with ventricular tachycardia (VT) or ventricular fibrillation (VF) and in survivors of cardiac arrest and to identify the factors that are associated with arrhythmia suppression and therefore might be helpful in predicting drug efficacy. BACKGROUND: Despite increasing use of the class III antiarrhythmic agent d,l-sotalol, data on its short- and long-term efficacy in a large patient cohort are lacking. Information on its long-term tolerability and safety is limited. METHODS: A total of 396 patients with inducible sustained VT or VF (VT/VF) underwent programmed stimulation before and after receiving oral d,l-sotalol (240 to 640 mg/day). Patients in whom VT/VF was rendered either noninducible or more difficult to induce (more extrastimuli or faster drive cycle length needed for VT/VF induction) were discharged on a regimen of oral d,l-sotalol. RESULTS: d,l-Sotalol suppressed VT/VF in 151 patients (38.1%) and rendered the arrhythmia more difficult to induce in 76 patients (19.2%). The extent of drug-induced prolongation of right ventricular refractoriness and a shorter VT cycle length at baseline were independent predictors of immediate drug efficacy. Torsade de pointes developed in seven patients (1.8%). Two hundred ten patients (53%) continued to receive d,l-sotalol and were followed up for 34 +/- 18 months (mean +/- SD). The actuarial rates for the absence of arrhythmic recurrence (either VT/VF or sudden death) at 1 and 3 years were 89% and 77%, respectively. Actuarial rates for overall survival at 1 and 3 years were 94% and 86%, respectively. VT/VF suppression by d,l-sotalol was an independent discriminant variable that separated patients with and without arrhythmia recurrence. However, noninducibility of VT/VF did not predict freedom from sudden death. CONCLUSION: Oral d,l-sotalol is effective and safe in patients with VT/VF. However, sudden cardiac death develops in a significant proportion of patients, and programmed stimulation seems to be of limited value for its prediction.

Administration, Oral↗
PubMed1997

A prognostic computer model to predict individual outcome in interventional cardiology. The INTERVENT Project.

It is not yet possible to predict an individual's outcome from percutaneous transluminal coronary angioplasty or alternative/adjunctive coronary interventional techniques. The purpose of the INTERVENT project is to redefine complications associated with coronary interventions, to set up a prognostic computer model to predict individual outcome and to compare the results to those of conventional statistical techniques. 2500 data items were analysed in 455 consecutive patients (mean age: 61.1 +/- 8.3 years; range 33-84 years; 80.4% male, 16.7% unstable angina, 5.1%/10.1% acute/subacute myocardial infarction) undergoing coronary interventions at three university centres. In-lab/out-of-lab complication rates were 0.4%/0.9% (death), 1.8%/0.2% (abrupt vessel closure with myocardial infarction) and 5.5%/4.0% (haemodynamic complications). Computer algorithms derived by applying techniques from artificial intelligence were able (1) to reduce the set of possible relevant risk factors from 2500 to about 40, (2) to predict individual risk with an accuracy of > 95% and (3) to explain the structural relationship between outcome and risk factors. Patient data from two centres were used to construct and test the algorithm. Data from a third centre were used to evaluate the algorithm. The most important predictors-were acute myocardial infarction, heart failure (NYHA class > II), unstable angina, complex lesions, high low density lipoprotein cholesterol and duration of coronary heart disease. Neither age nor gender impaired the percutaneous transluminal coronary angioplasty results in acute ischaemic syndromes; however, for stable angina, procedural risk increased with age. There was little risk from primary percutaneous transluminal coronary angioplasty in acute myocardial infarction in patients with NYHA heart failure classes I-II; however, the risk was high for patients in NYHA classes > II, either with or without additional thrombolysis. Alternative/adjunctive intervention techniques were no predictors for in-lab-, but were predictors for post-procedural complications.

Adult↗
PubMed1997

Prediction of arrhythmia risk based on signal-averaged ECG in postinfarction patients.

In patients surviving acute MI, identification of those at high risk for life-threatening ventricular tachyarrhythmias and/or sudden death is of great importance. Numerous strategies based on indices such as the degree of left ventricular dysfunction, complex ventricular arrhythmias, or parameters of autonomic dysfunction have not yet led to an effective identification of the individual patient at risk. During the past decade, many investigators have recorded low amplitude, high frequency components in the terminal QRS complex (so-called late potentials) from patients prone to sustained ventricular tachycardia. The SAECG has been used to predict life-threatening tachyarrhythmias in patients after acute MI and to screen for inducible ventricular tachycardia in patients with unexplained syncope or sustained ventricular tachycardia. This review article describes the most frequently applied methodology and clinical applications of the SAECG in post-MI patients and discusses the usefulness of noninvasive recordings in various other clinical settings.

Arrhythmias, Cardiac↗
PubMed1997

Radiofrequency catheter ablation of the anterosuperior and posteroinferior atrial approaches to the AV node for treatment of AV nodal reentrant tachycardia: techniques for selective ablation of "fast" and "slow" AV node pathways.

Radiofrequency catheter ablation has been established as a first-line curative treatment modality in patients with symptomatic AV nodal reentrant tachycardia (AVNRT). The successful sites of stepwise catheter ablation approaches of the so-called fast and slow pathways strongly suggest that AVNRT involves the atrial approaches to the AV node. The typical fast pathway ablation sites are located anterosuperior toward the apex of the triangle of Koch, which also contains the compact AV node, whereas the usual slow pathway ablation sites are located posteroinferior toward the base of the triangle of Koch at a greater distance to the compact AV node and bundle of His. Accordingly, ablation studies with large patient cohorts have demonstrated that fast pathway ablation carries a higher risk of inadvertent complete AV block. Thus, the slow pathway is clearly the primary target site, and fast pathway ablation is rarely necessary. Different approaches for slow pathway ablation have been elaborated: anatomically oriented stepwise techniques, ablation guided by double potentials recorded within the area of the slow pathway insertion, and combined techniques. The modern concept of AVNRT suggests that this arrhythmia involves the highly complex three-dimensional nonuniform anisotropic AV junctional area. Accordingly, mapping and ablation studies demonstrated that the anterior approach is not identical with fast pathway ablation, and the posterior approach is not identical with slow pathway ablation. Therefore, it is essential for interventional electrophysiologists to familiarize themselves with the anatomic and electrophysiologic details of this complex and variable specialized AV junctional region. In this review, the anatomic and pathophysiologic aspects of the AV junctional area as they relate to interventional therapy are summarized briefly, and the catheter techniques for ablation of the so-called fast and slow AV nodal pathways for the treatment of AVNRT are described.

Atrioventricular Node↗
PubMed1997

Three-dimensional electromagnetic catheter technology: electroanatomical mapping of the right atrium and ablation of ectopic atrial tachycardia.

INTRODUCTION: The difficult catheter orientation and navigation associated with conventional technology and mono-/multiplane fluoroscopy may complicate ablation procedures of atrial tachycardias. A new three-dimensional catheter technology for electroanatomical mapping of the right atrium and ablation of ectopic atrial tachycardia is described. METHODS AND RESULTS: A novel electromagnetic catheter-based mapping system was investigated for electroanatomical mapping of the entire right atrium in 12 patients. The system reconstructed three-dimensional maps from the multitude of endocardial sites that were sequentially mapped and color coded the individual activation times. The electrophysiologic information was superimposed on the geometry of the mapped area. The anatomical landmarks of the right atrium, i.e., the tricuspid annulus, mouth of the coronary sinus, ostia of the superior and inferior venae cavae, and right atrial appendage, could be depicted in all cases. The sinus node area and the preferential conduction along the crista terminalis could be delineated. In four patients with ectopic atrial tachycardia, the earliest endocardial activation could be identified with high spatial resolution as a "hot spot." After completion of the mapping procedure, the ablation catheter could be reliably renavigated to the site of origin, and ablation was successful with one or two impulses. In one patient with previous atrial septal repair, the activation map allowed the reconstruction of a long line of conduction block induced by the atriotomy. CONCLUSION: Three-dimensional electroanatomical mapping of the right atrium allowed detailed reconstruction of the chamber geometry and activation sequence. The sites of origin of ectopic atrial tachycardias could be identified precisely. The system allowed accurate renavigation to the site of earliest activation, thereby guiding successful ablation of the foci.

Adult↗
PubMed1997

Undersulfation of proteoheparan sulfate stimulates the expression of basic fibroblast growth factor and protein synthesis but suppresses replication of coronary smooth muscle cells.

Heparan sulfate proteoglycans are obligatory for receptor binding and mitogenic activity of the basic fibroblast growth factor (bFGF). In the present study the influence of undersulfated heparan sulfate on the expression of basic fibroblast growth factor and coronary smooth muscle cell (cSMC) proliferation was investigated. Chlorate, known to be an inhibitor of ATP-sulfurylase, was used as a tool to suppress sulfation of heparan sulfate. When cultured cSMC were treated with 10 mM sodium chlorate in sulfate-depleted medium, the cell number and [3H]thymidine incorporation decreased by 76% and 66% respectively, while the protein content per cell was doubled. At the same time the [35S]sulfate incorporation into cell-associated proteoglycans was reduced by 90%. The remaining minimal amount of available [35S]radioactivity was preferably incorporated into heparan sulfate. Under the same conditions the [6-(3)H]glucosamine incorporation into glycosaminoglycans was not impaired. The chlorate-induced increase of cell protein content includes an overexpression of bFGF, which increased from 6-8 ng to 18-22 ng/mg cell protein. However, no changes in the distribution of bFGF between the intracellular and pericellular compartment could be observed. Cell cycle analysis by FACS revealed a G1 arrest of the cell cycle with increase of the G1/S ratio from 2.9 (control) to 6.1 (chlorate) but the DNA content per cell corresponded to normal diploid cells both in control and chlorate-treated cells. The chlorate effect can be abolished by addition of 5 mM sodium sulfate to the cultures. Our results demonstrate an inverse association between the sulfation of heparan sulfate and the expression of bFGF. They suggest that chlorate blocks the cell cycle in the late G1-phage and that mitogenesis of cSMC requires fully sulfated cell-associated proteoheparan sulfate.

Animals↗