[Syncope in older patients : Who needs what and when?] / Synkope beim älteren Patienten : Wer braucht was wann?

The aim of diagnostic procedures in the context of syncope is the exclusion of cardiac diseases. Cardiac diseases as the cause of syncope have a high influence on the rate of mortality.

[Dronedarone]. / Dronedaron.

Dronedarone is a new antiarrhythmic agent, approved in January 2010 for the therapy of atrial fibrillation and for rate control in tachyarrhythmic atrial fibrillation. It was developed with the goal of replicating the high antiarrhythmic potency of amiodarone but with fewer side effects. An essential difference compared to amiodarone is the elimination of the iodine substituents in order to avoid the thyroid side effects and the addition of a methane-sulfonamyl group group in order to reduce lipophilicity. In the meantime, the Guidelines of the European Society of Cardiology list dronedarone in the group of antiarrhythmically effective substances along with the class 1c antiarrhythmia agents and amiodarone that can be administered before catheter ablation. Dronedarone is a well-tolerated antiarrhythmic agent, which due to its side effect profile permits its application in an outpatient setting in patients with atrial fibrillation.

[Atrial fibrillation ablation: who comes into consideration?]. / Vorhofflimmerablation: Wer kommt in Frage?

Atrial fibrillation ablation is, since the introduction of the guidelines in 2006 and which were updated in 2007, now a standard procedure in many electrophysiological centers. Pulmonary vein isolation has proven itself as a way to eliminate focal triggers. From pathophysiological studies of atrial fibrillation development, it is known that ablation performed early in paroxysmal atrial fibrillation has the highest chance for success. In patients with persistent or permanent atrial fibrillation, success rates are lower and repeat interventions are needed more often. Therefore, continuation of antiarrhythmic drug therapy is often necessary in these patient groups. Thus, the curative use of ablation for atrial fibrillation is only possible with the current techniques for patients with paroxysmal atrial fibrillation.

[Pulmonary vein isolation with multipolar ablation catheters for the treatment of paroxysmal atrial fibrillation]. / Pulmonalvenenisolation mit multipolaren Ablationskathetern zur Behandlung von paroxysmalem Vorhofflimmern.

Atrial fibrillation (AFIB) is the most common atrial rhythm disease and is associated with an increased risk of thromboembolic and cardiac complications. Different therapies are used in clinical routine: frequency control with anticoagulants and rhythm control. In patients with paroxysmal AFIB but without structural heart disease, antiarrhythmic drug therapy was previously first priority; however, pulmonary vein catheter ablation is becoming more important. "Single tip" systems, ultrasound, and various balloon techniques have been used in clinical routine. New radiofrequency systems with multipolar radiofrequency ablation catheters, however, give hope for better outcomes with fewer intraprocedural complications, as well as shorter procedure and fluoroscopy times.

[Catheter ablation of typical atrial flutter]. / Katheterablation von isthmusabhängigem Vorhofflattern.

Atrial flutter is one of the most common supraventricular arrhythmic diseases and occurs with an incidence of 88/100,000. The high risk for thromboembolic events is similar to that for atrial fibrillation and also has the risk for fast conduction to the ventricle. Pharmacological treatment is not significantly effective. Catheter ablation of common atrial flutter offers an alternative with a high quality outcome ranging from 90-96% and a low recurrence rate of 2-6%. Radiofrequency catheter ablation of the cavotricuspidal isthmus is an established treatment for common atrial flutter. Modern techniques like cryo-ablation show nearly the same results and will be an alternative to the RF ablation in the future.

[New ablation techniques in ventricular tachycardia]. / Neue Ablationstechniken bei ventrikulären Tachykardien.

Catheter ablation of ventricular tachycardia (VT) has proven to be effective in only a minority of VT patients. Therefore there is great interest in the development of new mapping and ablation techniques. New mapping procedures include multielectrode catheter mapping via the epicardial cardiac arteries and veins and the multielectrode basket catheter. Computerized non-contact mapping offers a three-dimensional approach in defining the activation sequence during VT. New ablative techniques are "cooled" radiofrequency energy application and microwave ablation which allow deeper and larger lesions. Already used in clinical practice are the application of laser energy and chemical ablation. New developments are ultrasound-, cryo- and thermal ablation. It can be suspected that some of these new achievements will lead to better results in VT ablation.

[Drug therapy of ventricular tachycardia]. / Medikamentöse Therapie ventrikulärer Tachykardien.

For the emergency treatment of sustained, hemodynamically stable ventricular tachycardia, antiarrhythmic drugs are the therapy of choice. Mostly class I antiarrhythmic drugs, such as lidocaine or ajmaline, are preferred. In hemodynamically unstable ventricular tachycardia, electrical cardioversion should be applied, in case of recurrences, followed by pharmacological treatment with class I antiarrhythmic drugs or amiodarone. For the primary prevention of sudden cardiac death, beta-blockers and/or amiodarone are the only effective drugs. In the secondary prevention, only the implantable cardioverter/defibrillator has proved to improve the prognosis of the patients.

Coxsackievirus genome in myocardium of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Enteroviruses are known as major infectious agents for inflammatory heart diseases such as myocarditis and dilated cardiomyopathy (DCM). Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by replacement of right ventricular myocardium by fatty and fibrous tissue. In about 65% of patients inflammatory infiltrates suggest an inflammatory or infectious etiopathogenesis. To test this hypothesis, we investigated endomyocardial biopsies of patients with ARVC, with myocarditis or DCM, and from patients with non-inflammatory cardiac disorders for the presence of enteroviral genome. Enteroviral RNA with homology to coxsackieviruses type B was detected in 3 of 8 patients with ARVC (37.5%), in 7 of 23 patients with myocarditis or DCM (30.4%), but in none of 5 patient with non-infectious myocardial diseases (p < 0.05 compared to ARVC patients). These results support earlier suggestions that coxsackievirus infection of the myocardium is possibly related to the pathogenesis of ARVC.

Empirical versus tested antitachycardia pacing in implantable cardioverter defibrillators: a prospective study including 200 patients.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) reduce the risk of sudden cardiac death. The objective of this study was to evaluate whether testing of antitachycardia pacing (ATP) for induced ventricular tachycardias (VTs) at predischarge examination can predict ATP success during follow-up. METHODS AND RESULTS: The study covers 200 consecutive patients who received ICD implants from June 1991 through December 1995. All underwent electrophysiological testing. In 54 patients (ATP tested, group T), ATP terminated induced VTs successfully. In 146 patients (empirically programmed ATP, group E), only ventricular fibrillation could be induced, including 18 with unsuccessful ATP attempts for induced VTs. Disregarding the results of ATP testing, the same ATP scheme was programmed in all patients: three attempts of autodecremental ramp with 81% of the VT cycle length, with 8 to 10 pulses. During a follow-up of 20.4 +/- 10 months, 95% of 3819 spontaneous VTs were successfully terminated with ATP in 42 patients of group T. In group E, 90% of 1346 spontaneous VTs in 81 patients were terminated with ATP. Acceleration after ATP occurred in 2% in group T versus 5% in group E. The success for all episodes in individual patients was > or =90% in >60% of the ATP tested and empirically programmed patients. CONCLUSIONS: The results of this 200-patient prospective study comparing tested versus empirical ATP show high success (95% versus 90%) for VT termination, with low rates of acceleration. ATP is safe and very effective and should be programmed "on" in all patients regardless of the predischarge EP inducibility.

Inhibition of the voltage-dependent calcium current by extracellular ATP in hamster ventricular cardiomyocytes.

The modulation of the high-voltage-activated calcium current (ICa) by external ATP was examined in single ventricular cardiomyocytes of the hamster using the whole-cell configuration of the patch-clamp technique. Extracellular application of ATP (0.1-100 microM) was found to inhibit ICa reversibly. The inhibition followed a slow time course (half time approximately 25 s) and was accompanied by very small changes of the holding current and no shift in the current-voltage relationship. With 100 microM ATP, peak ICa was reduced by approximately 30%. This response was not blocked by the P1 inhibitor 8-cyclopentyl-1,3-dipropylxanthine. The nonhydrolyzable ATP analogs adenosine 5'-O-(3-thiotriphosphate) and AMP-adenosine 5'-[beta,gamma-imido]triphosphate also reduced ICa. The ATP analog alpha,beta-methylene-ATP was about equipotent with ATP at 50 microM. Internal guanosine 5'-O-(3-thiotriphosphate) (200 microM) rendered the ATP-mediated inhibition of ICa poorly reversible, whereas internal guanosine 5'-O-(2-thiodiphosphate) (200-500 microM) had no effect. Holding the intracellular adenosine 3',5'-cyclic monophosphate concentration at a constant high level did not alter the ATP response. We conclude that external ATP inhibits ICa via a P2 purinergic receptor in hamster ventricular myocytes. Our results suggest the involvement of a G protein not coupled to adenylate cyclase. The inhibition of ICa by extracellular ATP might have pathophysiological relevance under conditions of myocardial injury.

Mipafox differential inhibition assay for heart muscle cholinesterases: substrate specificity and inhibition of three isoenzymes by physostigmine and quinidine.

1. A differential inhibition assay was developed for the quantitative determination of cholinesterase isoenzymes acetylcholinesterase (AChE; EC 3.1.1.7), cholinesterase (BChE; EC 3.1.1.8), and atypical cholinesterase in small samples of left ventricular porcine heart muscle. 2. The assay is based on kinetic analysis of irreversible cholinesterase inhibition by the organophosphorus compound N,N'-di-isopropylphosphorodiamidic fluoride (mipafox). With acetylthiocholine (ASCh) as substrate (1.25 mM), hydrolytic activities (A) of cholinesterase isoenzymes were determined after preincubation (60 min, 25 degrees C) of heart muscle samples with either saline (total activity, A tau), 7 microM mipafox (AM1), or 0.8 mM mipafox (AM2): (BChE) = A tau-AM1, (AChE) = AM1-AM2, (Atypical ChE) = AM2. 3. The mipafox differential inhibition assay was used to determine the substrate hydrolysis patterns of myocardial cholinesterases with ASCh, acetyl-beta-methylthiocholine (A beta MSCh), propionylthiocholine (PSCh), and butyrylthiocholine (BSCh). The substrate specificities of myocardial AChE and BChE resemble those of erythrocyte AChE and serum BChE, respectively. Michaelis constants KM with ASCh were determined to be 0.15 mM for AChE and 1.4 mM for BChE. 4. Atypical cholinesterase, in respect to both substrate specificity and inhibition kinetics, differs from cholinesterase activities of vertebrate tissue and, up to now, could be identified exclusively in heart muscle. The enzyme's Michaelis constant with ASCh was determined to be 4.0 mM. 5. The reversible inhibitory effects of physostigmine (eserine) and quinidine on heart muscle cholinesterases were investigated using the differential inhibition assay. With all three isoenzymes, the inhibition kinetics of both substances were strictly competitive. The physostigmine inhibition of AChE was most pronounced (Ki = 0.22 microM). Quinidine most potently inhibited myocardial BChE (Ki = 35 microM).

Standardized assessment of psychological well-being and quality-of-life in patients with implanted defibrillators.

The ICD has become a standard treatment for patients with malignant arrhythmias. Despite its benefits it may cause additional discomfort to the patients. Thus, quality-of-life needs to be assessed in these patients. Previous studies have used only small samples or unstandardized measures of quality-of-life that do not allow comparisons with other patient groups. The present study used standardized questionnaires for a cross-sectional assessment of psychological well-being and quality-of-life in ICD patients and to compare them to a similar group of coronary artery disease (CAD) patients without ICD. Overall, quality-of-life did not differ between both groups, ICD patients being less anxious than the CAD group. With increasing numbers of ICD shocks, however, the percentage of psychologically distressed ICD patients rose from 10% to > 50%. Psychologically distressed patients had significantly worse scores on most of the quality-of-life subscales, showed less treatment satisfaction, and more negative attitudes. It is concluded that ICD patients have an acceptable mean quality-of-life and low mean anxiety. However, a relevant subgroup of about 15%, especially patients with frequent shocks, experience psychological distress and reduced quality-of-life and should receive special care.