T wave spectral variance: A new method to determine inhomogeneous repolarization by T wave beat-to-beat variability in patients prone to ventricular arrhythmias.

Inhomogeneous repolarization is considered to be associated with increased risk of ventricular arrhythmias, but exact determination of the end of the T wave is difficult, and a single measurement of the QTc interval may be insufficient for risk stratification. A new algorithm was therefore developed to determine the beat-to-beat variability of the T wave in Holter electrocardiographic recordings. This algorithm, termed T Wave Spectral Variance (TWSV) uses the two-dimensional fast Fourier transform to determine the beat-to-beat variability of the T wave in Hotter ECG recordings.

Aggressive lowering of fibrinogen and cholesterol in the prevention of graft vessel disease after heart transplantation.

Background: A combined treatment of statins and extracorporeal H.E.L.

The combined transvenous implantation of cardioverter defibrillators and permanent pacemakers.

We developed criteria for implantation and programming of permanent endocardial pacemakers in patients with a nonthoracotomy ICD system. These criteria were prospectively used in 10 patients who recieved an ICD prior to (n = 5) or following (n = 5) implantation of a dual chamber (n = 6) or ventricular (n = 4) pacemaker with a unipolar (n = 4) or bipolar (n = 6) lead configuration. All patients were tested for interactions or malfunctions.

[Functional late potential analysis in the 24-hour electrocardiogram].

Background: It has not been investigated, whether repeated late potential analysis within 24 hours provides the recognition of functional changes and could be superior to a single analysis.

Method: Therefore we performed late potential analysis from the 24 hour Holter-ECG after validation of the method using a standard analysis system (Predictor((R))) and investigated, whether late potential appearance varied over the day and funtional changes were associated with ventricular arrhythmias. Holter tape recordings in 120 post-infarction patients were analyzed.

Management of patients with life-threatening ventricular tachyarrhythmias in the defibrillator era: the need to differentiate.

Patients with a history of sustained ventricular tachyarrhythmias form an extremely inhomogeneous group with respect to presenting arrhythmia, underlying cardiac disease, and therefore, risk of dying suddenly. For subgroups such as ventricular tachycardia in the absence of underlying cardiac disease, radiofrequency catheter ablation offers cure. In others, implantation of a cardioverter defibrillator already appears to have gained the therapy of first choice, leaving only a secondary role to antiarrhythmic drugs.

Simvastatin reduces graft vessel disease and mortality after heart transplantation: a four-year randomized trial.

Background: Accelerated graft vessel disease (GVD) represents the most serious long-term complication of heart transplantation. A possible cause underlying this progressive coronary vascular disease is believed to be post-transplantation hypercholesterolemia.

Methods And Results: In a 4-year prospective randomized study with heart transplant recipients, the efficacy of primary antihypercholesterolemic therapy with simvastatin was compared with that of general dietary therapy.

Influence of anodal electrode position on transvenous defibrillation efficacy in humans: a prospective randomized comparison.

Nonthoracotomy lead systems for implantable cardioverter defibrillators (ICDs) have reduced operative mortality and morbidity as compared to epicardial lead systems but are usually associated with higher defibrillation thresholds (DFTs). The purpose of this prospective randomized trial was to investigate if the second defibrillation electrode in the left subclavian vein can increase defibrillation efficacy and decrease DFT as compared to the superior vena cava (SVC) position in nonthoracotomy lead systems for ICDs. Seventeen patients (mean age: 49.

Competitive RT-PCR for studying gene expression in micro biopsies.

The technique of RT-PCR has become a powerful method for studying gene expression in various species and tissues. Here we present a competitive PCR for quantitative measurement of absolute levels of mRNA molecules for the regulatory alpha 2/delta subunit of the high-voltage-activated dihydropyridine sensitive human cardiac L-type calcium channel. With the method described the dynamic process of cardiac gene expression can be studied in human endomyocardial biopsies in different patient collectives and even in the individual.

[Genesis, pathophysiology and clinical aspects of cardiac arrhythmias. Characterization of the risk patient].

Extrasystoles and both supraventricular and ventricular tachycardias may occur as a complication of almost any underlying cardiac disease and many extracardiac causes; on the other hand, also a patient without any detectable structural heart disease may present with these arrhythmias. Refined mapping techniques of the intracardiac conduction process have let to important new informations about the pathophysiology of sustained tachycardias (focal impulse formation, macro-reentry) with practical consequences, for example when ablation of these arrhythmias by radiofrequency catheter ablation is considered. Cardiac arrhythmias may lead to both typical and atypical symptoms.

[Stored electrograms to differenciate between adequate and inadequate ICD therapy].

The introduction of implantable cardioverter defibrillators in 1980 by Mirowski et al, offered a new therapeutic device for the treatment of ventrikular tachyarrhythmias. In the beginning it was only possible to evaluate arrhythmic events by analysis of the therapy-counter in combination with clinical symptoms. Even rapid ventricular tachyarrhythmias may not produce significant symptoms prior to ICD shock in more than 50% of patients.

[A comparison of ultrafast computed tomography, magnetic resonance angiography and selective angiography for the detection of coronary bypass patency].

Purpose: Validation of ultrafast-CT and MR-angiography (MRA) in comparison with angiography for detection of early postsurgical arterial and venous coronary artery bypass graft (CABG) patency.

Methods: 21 patients with a total of 55 CABG (34 venous and 21 arterial) were studied with angiography, ultrafast-CT (EBT), and MRA.

Results: With EBT, patency of 43/45 angiographically patent CABG could be correctly assessed (sensitivity: 96%).

Comparison of a unipolar defibrillation system with a dual lead system using an enlarged defibrillation anode.

The unipolar system for transvenous defibrillation, consisting of a single right ventricular lead as the cathode and the device shell as anode, has been shown to combine low defibrillation thresholds (DFTs) and simple implantation techniques. We compared the defibrillation efficacy of this system with the defibrillation efficacy of a dual lead system with a 12-cm long defibrillation anode placed in the left subclavian vein. The data of 38 consecutive patients were retrospectively analyzed.

[The value of ultrafast computerized tomography in detection of the patency of coronary bypasses].

Bypass graft patency with ultrafast computed tomography (= Electron Beam Tomography, EBT) was examined in 72 bypass grafts (47 saphenous veins, 25 internal mammary arteries) in 30 patients and compared with coronary angiography. Angiography was performed a mean of 4.4 +/- 3.

[Radiofrequency catheter ablation of an accessory atrioventricular conduction pathway with persistent left superior vena cava and hypertrophic cardiomyopathy].

A 43-year-old man with a 30-year history of WPW-syndrome and a hypertrophic cardiomyopathy developed acute heart failure after onset of atrial fibrillation with fast antegrade conduction, which could be converted to sinus rhythm with antiarrhythmic medication. Catheterization of the coronary sinus during EP testing demonstrated a persistent left superior vena cava. The accessory pathway could be localized at the orifice of an atypical epicardial vein.

[Incidence and localization of apoptosis bodies in human arteriosclerosis lesions].

Increased density of smooth muscle cells is an accepted feature of human restenosis after angioplasty. In addition to migration and proliferation, deregulated forms of programmed cell death may represent pathogenic mechanisms which lead to increased intimal cellularity. The goal of the present study was (i) to demonstrate programmed cell death in human plaque tissue by the detection of apoptotic bodies and to distinguish it from cellular necrosis, (ii) to evaluate the frequency and the localization of apoptotic bodies, and (iii) to compare restenotic and primary lesions for different expression patterns.

Management of patients with life-threatening sustained ventricular tachyarrhythmias--the role of guided antiarrhythmic drug therapy.

Two recent studies have evaluated the utility of electrophysiologic (EP) testing in the treatment of patients with serious ventricular arrhythmias. The first study compared electrophysiologically guided antiarrhythmic drug therapy with nonguided beta-blocker therapy. Patients without inducible arrhythmias were assigned to oral metoprolol; patients with inducible arrhythmias were randomly assigned to receive either oral metoprolol or EP-guided drug therapy with propafenone, flecainide, disopyramide, sotalol, or amiodarone.

[Drug therapy of atrial fibrillation: control of heart rate versus establishing sinus rhythm].

Our knowledge about efficacy and safety of various therapeutic strategies is insufficient, especially with respect to the direct comparison of reestablishment of sinus rhythm by drugs in comparison to rate control. Therefore, an initiative of the German Working Group on Electrophysiology of the Deutsche Gesellschaft für Kardiologie--Herz- und Kreislaufforschung is urgently needed which will compare these strategies in a prospective controlled trial (pharmacologic intervention in atrial fibrillation PIAF: Reestablishment of sinus rhythm by the drug amiodarone, in addition DC-defibrillation if necessary; rate control with the calcium antagonist diltiazem). It is hoped that this study will give quantitative data about recurrences of arrhythmia, quality of life and exercise capacity.

Regional differences in current density and rate-dependent properties of the transient outward current in subepicardial and subendocardial myocytes of human left ventricle.

Background: Recordings of outward currents in human ventricular myocytes revealed the presence of a large calcium-insensitive transient outward current. This current has been suggested to contribute significantly to regional electrophysiological heterogeneity in myocardial cells and tissue of several animal species and to cause electrical gradients across the ventricular wall.

Methods And Results: The patch-clamp technique was used to record action potentials and outward currents in myocytes enzymatically isolated from thin subepicardial and subendocardial layers of human nonfailing and failing left ventricle.

[Use of ultra-fast computerized tomography in diagnosis of coronary heart disease].

Ultrafast or electron beam tomography (EBT) permits acquisition of images in 50-100 ms. An artifact-reduced display of heart and vessel structures as well as calcifications can be achieved. Therefore, EBT can be used for the detection and quantification of coronary artery calcification.

Failures of epicardial and transvenous leads for implantable cardioverter defibrillators.

Lead failures constitute a major risk for patients with an implantable cardioverter defibrillator (ICD). However, data about the incidence and patterns of ICD-lead failures in a larger population are lacking. We analyzed the short-term and midterm performance of 27 epicardial and 103 nonthoracotomy ICD-lead systems during a follow-up period of 36 +/- 21 months and 22 +/- 10 months, respectively (p < 0.

The left subclavian vein as an alternative site for implantation of the second defibrillation lead.

The optimal placement for the second defibrillation lead in a two-lead system has never been addressed. We retrospectively reviewed the data of 33 patients with an average age of 59.2 years (range 41-78 years), predominantly male (n = 29), who underwent implantation of a cardioverter defibrillator (ICD) for treatment of ventricular tachycardia (n = 19) or ventricular fibrillation (n = 14).