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We report the case of a 30-year-old man who presented to our emergency department with rapid heart beat and a narrow complex tachycardia at a rate of 215 beats per minute. With the working diagnosis of Wolf-Parkinson-White syndrome with paroxysmal orthodromic tachycardias, we performed an electrophysiological study. In this examination, there was a para-Hisian accessory pathway with very fast, prognostically relevant conduction properties. In order to protect the His bundle that is located deeper in the tissue and to avoid a deeper lesion, we decided to use high-power short-duration ablation. This method, which was recently used in three-dimensional-controlled radiofrequency ablation of pulmonary veins, causes more superficial lesions in order to protect the surrounding tissue. In our case, using the high-power short-duration method, we were able to successfully ablate the para-Hisian accessory pathway, while protecting the His bundle near the ablation site.Wir berichten über einen 30-jährigen Patienten, der mit Herzrasen bei einer Schmalkomplextachykardie mit einer Herzfrequenz von 215/min in unserer zentralen Notaufnahme vorgestellt wurde. Unter der Arbeitsdiagnose eines Wolf-Parkinson-White-Syndroms mit paroxysmalen orthodromen Tachykardien führten wir eine elektrophysiologische Untersuchung durch. In dieser fand sich eine parahisär gelegene akzessorische Leitungsbahn mit sehr schnellen, prognostisch relevanten Leitungseigenschaften. Um das tiefer im Gewebe liegende His-Bündel zu schonen und eine tiefergehende Läsion zu vermeiden, entschieden wir uns für eine Ablation mittels „high-power short-duration“. Diese Methode wird neuerdings bei der 3D-gesteuerten Radiofrequenzablation von Pulmonalvenen eingesetzt und verursacht Läsionen mit geringerer Tiefe, um umliegendes Gewebe zu schonen. In unserem Fall konnten wir mit Verwendung der High-power-short-duration-Methode eine parahisär liegende akzessorische Leitungsbahn erfolgreich unter Schonung des tiefer im Gewebe liegenden His-Bündels abladieren.

The AV-reentrant tachycardia (AVRT) is a supraventricular tachycardia with an incidence of 1-3/1000. The pathophysiological basis is an accessory atrioventricular pathway (AP). Patients with AVRT typically present with palpitations, an on-off characteristic, anxiety, dyspnea, and polyuria. This type of tachycardia may often be terminated by vagal maneuvers. Although the clinical presentation of AVRT is quite similar to AV-nodal reentrant tachycardias, the correct diagnosis is often facilitated by analyzing a standard 12-lead ECG at normal heart rate showing ventricular preexcitation. Curative catheter ablation of the AP represents the therapy of choice in symptomatic patients. This article is the fourth part of a series written to improve the professional education of young electrophysiologists. It explains pathophysiology, symptoms, and electrophysiological findings of an invasive EP study. It focusses on mapping and ablation of accessory pathways.

The Wolff-Parkinson-White syndrome is a usually benign heart disease with accessory pathways. Circling excitations arise between atria and ventricles which can lead to cardiac arrhythmias. Cases of sudden cardiac death are rare (0.2 %). Risk factors for sudden cardiac death in patients with WPW syndrome are old age, several accessory pathways, male sex and previous syncopes. A 16-year-old girl was found lying dead in her bed. The evening before, she didn't feel well and complained about abdominal pain. The girl had known epilepsy and Wolff- Parkinson-White syndrome. The macroscopic and histological findings are presented and discussed with reference to the pertinent literature.

Interruption of inferior vena cava with azygos continuation is a rare venous anomaly. We report the case of a 17 old male with Wolf-Parkinson-White syndrome and a persistent vena azygos. Despite the complex anatomical situation, it was possible to safely ablate a lateral accessory pathway with radiofrequency energy using a femoral retrograde approach.

Atrial fibrillation (AF) is the most common form of arrhythmia in the intensive care unit (ICU) and is associated with increased mortality. A total of five types of AF can be distinguished: initially diagnosed, paroxysmal, persistent, long-standing persistent and permanent AF. In addition to the initial treatment, antithrombotic therapy, rate and rhythm management can be used. The treatment of comorbidities is part of the patient management and for patients with increased risk of thromboembolic events anticoagulation is recommended. The simplest risk assessment scheme is the CHADS score. In the acute setting rate control is important. Direct current cardioversion is urgently recommended for patients with AF when hemodynamic instability is present even in patients with AF and pre-excitation in Wolff-Parkinson-White syndrome. Pharmacological cardioversion may be considered in patients with AF when hemodynamic stability is present. When choosing the antiarrhythmic agent for critically ill patients only amiodarone can be considered with some exceptions due to the specific contraindications.

Premature supraventricular or ventricular beats are frequently seen in children of all age groups and are in most instances a benign condition. Intermittent and infrequent premature beats usually are not an indication for a cardiologic work-up. If ventricular or supraventricular premature beats are frequent and persist over a period of weeks or months, we usually recommend a cardiological evaluation. In those patients where ventricular or supraventricular tachycardias are found, the treatment is based on symptomatology, frequency of arrhythmias and impact on quality of life. In ventricular tachycardias, the presence of underlying cardiac disease is of prognostic importance and treatment more aggressive. Idiopathic ventricular tachycardia without structural heart disease usually shows a benign course and has a good prognosis.

In 1930, Wolff, Parkinson and White described the clinical entity of what is today known as the preexcitation or WPW syndrome. In the preceding literature, the authors found four comparable cases. Later on, seven further cases published prior to 1930 were discovered. An analysis of the altogether eleven cases displays that, in addition to the anomalous ECG in sinus rhythm, nearly all typical electrocardiographic findings during the tachyarrhythmias are found in this early literature. As tachycardia ECGs especially help to understand the mechanism of the WPW syndrome, the question is discussed whether already Wolff, Parkinson and White would have been able to give the correct interpretation of the mechanism if they had taken into consideration their own tachycardia ECGs as well as those known to them from the literature.

We report the successful treatment with Heparin and Phenprocoumon of a large, free-floating, right atrial thrombus that developed after radiofrequency ablation (RFA) of an accessory pathway in a 24 year old patient with Wolff-Parkinson-White (WPW) Syndrome. In addition, "T-wave memory", a relatively common phenomenon after RFA in WPW-Syndrome, is demonstrated.

The antiarrhythmic properties of adenosine, its ultra-short half-life and the absence of frequent serious side effects make it a front-line agent in arrhythmia management, especially in the treatment of atrioventricular nodal reentrant tachycardia. Due to a shortening of atrial refractoriness, adenosine can facilitate the induction of atrial fibrillation. Life threatening tachycardias may result from a potential rapid conduction of atrial fibrillation over an accessory pathway especially if the latter one has a short antegrade refractory period. We report a case of a 59 year old female patient in which intravenous administration of adenosine during typical atrioventricular nodal reentrant tachycardia was followed by atrial fibrillation with rapid conduction over a hitherto unknown accessory pathway. After intravenous administration of adenosine the tachycardia was terminated successfully within 38 s. After a short period of asystole, spontaneous atrial fibrillation developed unmasking an antegrade preexcitation with subsequent rapid ventricular response (210 b/min). The three-lead ECG showed a narrow QRS complex tachycardia. Because of spontaneous conversion to sinus rhythm and the absence of hemodynamic compromise there was no need for external cardioversion. During electrophysiological study an antidromic atrioventricular reentrant tachycardia was recorded over a left posteroseptal accessory pathway including antegrade conduction properties only. Because of its ultrashort half-life, serious side effects after adenosine administration are rare. The possibility of life threatening proarrhythmias after intravenous adenosine administration should be taken into consideration if the etiology of a paroxysmal supraventricular tachycardia is not clear and a concomitant Wolff-Parkinson-White syndrome cannot be excluded. As with application of all intravenous antiarrhythmic agents, the administration of adenosine should only be performed if continuous ECG monitoring and cardioversion facilities are available and possible.

Recently intra-atrial defibrillation has become an interesting alternative to external defibrillation and drug therapy for the treatment of atrial fibrillation. Low-energy intra-atrial defibrillation can be used to restore sinus rhythm f.ex. after a failed external cardioversion or during an electrophysiologic study when the administration of antiarrhythmic drugs should be avoided. Additionally this new technique has led to the development of implantable atrial defibrillators for the treatment of selected patients suffering from chronic atrial fibrillation. Intra-atrial defibrillation seems to be a highly effective and safe method, but little experience exists concerning the outcome so far. Especially the potential risk of inducing ventricular pro-arrhythmia is subject of current controversy. We report the case of a 79-year-old patient suffering from WPW syndrome with a concealed bypass tract who was subject to an intra-atrial defibrillation during an electrophysiologic study. At the beginning of the study atrial fibrillation could be converted to sinus rhythm by a single low-energy atrial defibrillation (3 J.). After a short period of time a second intra-atrial defibrillation had to be performed in the same way because of recurrent atrial fibrillation. By this atrial shock ventricular fibrillation was induced, so that high energy external defibrillation became necessary. Analyzing the ECG a correct R-wave synchronization was found, but a rather short preceding RR interval (252 ms). In conclusion, low energy atrial defibrillation is gaining importance as a highly effective new technique to restore sinus rhythm in patients suffering from atrial fibrillation resistant to conventional therapies. Nevertheless potential risks have to be considered such as the induction of ventricular pro-arrhythmia. Therefore, a correct R-wave synchronization is obligatory and shock delivery should be withheld after short RR intervals. Future prospective randomized studies will have to show whether this new technique is really safe enough and superior to the conventional methods for restoring sinus rhythm in patients suffering from atrial fibrillation.

Cardiac arrhythmias are common causes of morbidity and mortality in clinical medicine. Much has been learned about cellular mechanisms of arrhythmogenesis in the past but genetic components have only recently been recognized for some heritable forms of arrhythmias. The long QT syndrome and the Brugada syndrome are both caused by molecular defects in ion channel proteins. Cardiac arrhythmias can also be associated with structural heart diseases. For example, sinus node dysfunction or AV-block can precede some forms of inherited dilated cardiomyopathy. A distinct genetic form of hypertrophic cardiomyopathy is associated with the Wolff-Parkinson-White syndrome and maps to chromosome 7q35. Arrhythmogenic right ventricular cardiomyopathy has a strong genetic basis and often manifests with ventricular tachycardia. Atrial fibrillation can also occur as familial disease and may be allelic with dilated cardiomyopathy as both diseases can be closely linked to chromosome 10q2.

Radiofrequency catheter ablation has established as the first line therapy for the curative treatment of patients with accessory pathways. For left-sided accessory pathways, the retrograde approach over the aortic valve is commonly used for ablation of the ventricular insertion. For right-sided and septal accessory pathways, the atrial insertion is usually approached from the right atrium. Atrioventricular accessory pathways irrespective of the exact localization can be successfully ablated in more than 90-95% of all cases. Severe complications associated with the ablation procedure are rare and occur in approximately 2-3% of patients treated. The recurrence rate after successful ablation is approximately 5-10%. Recurrences of accessory pathway conduction occur almost exclusively within the first 3 months following successful ablation whereas late recurrences are rare. Because of the favorable efficacy--risk profile, radiofrequency catheter ablation can be recommended as the first line therapy to all symptomatic patients with accessory atrioventricular pathways.

Radiofrequency current catheter ablation has gained acceptance as primary long-term therapy for patients with symptomatic accessory pathways and symptomatic atrioventricular nodal reentrant tachycardia (AVNRT) with frequent recurrences. In both arrhythmias, curative treatment is possible in more than 90% of cases at a low complication rate although an incidence of about 1% complete AV block after slow pathway ablation has to be taken into account when this therapy is considered. The recurrence rate is 3-10% for accessory pathways and 0-15% for AVNRT. The high success rate of catheter ablation has already led to a shift in the indications for the procedure where the percentage of patients with accessory pathways is decreasing and there is an increase of patients with AVNRT and newer indications (atrial flutter, focal atrial tachycardias).

In three asymptomatic children an isolated myocardial noncompaction was detected by echocardiography at age 11 months, 5 weeks and 5.5 years. In the first male infant both ventricles and septum were severely affected and myocardial function was depressed. Nevertheless, during a follow up of 16 months he remained asymptomatic on anticongestive therapy. In the other two children apex and lateral wall of the left ventricle were affected and myocardial function was still normal. The second boy had also an infantile epilepsy-encephalopathy syndrome and the third child (a girl) had a Wolff-Parkinson-White syndrome; an association of either syndromes with myocardial noncompaction has not been reported earlier.Myocardial noncompaction (spongy myocardium) is a rare maldevelopment, which occurs either associated with certain congenital heart defects or, even more rarely, isolated, as the two cases reported here. Myocardial failure, severe arrhythmias or thromboembolism may occur at any age and determine the outcome. Clinical course, therapy and prognosis are similar to dilatative cardiomyopathy, which represents an important differential diagnosis.

Supraventricular tachycardia is a frequent cause of disease in patients with congenital heart defects and has a potentially high impact on quality of life, morbidity and mortality of this patient cohort. Conventional treatment often fails to avoid recurrences of tachycardia in a long-term perspective. Potential side effects of antiarrhythmic drugs include aggravation of heart disease related disturbances of impulse generation and conduction properties or negative inotropic effects on haemodynamically impaired ventricular chambers. For these reasons, interventional electrophysiology is increasingly used for the treatment of supraventricular tachycardias in patients with congenital heart disease. Until March 1998 a total of 83 patients with congenital heart defects underwent an attempt for radiofrequency current treatment of supraventricular tachycardias. Among these were 36 children with an age of 5 months to 15 years (8.2 +/- 4.6 years) and 4.7 grown ups with an age of 17 to 76 years (39.3 +/- 14.3 years). In a natural course or preoperative status of the congenital heart disease were 35 patients, while palliative or corrective surgery was performed in 48 patients. Supraventricular tachycardia was based on a total of 63 congenital arrhythmogenic substrates, among them were 53 accessory pathways, 4 Mahaim fibres, 5 functionally dissociated AV-nodes and an anatomically doubled specific conduction system including 2 distinct AV-nodes in one case. In the remaining patients with tachycardia based on acquired arrhythmogenic substrates there were 45 incisional atrial reentrant tachycardias, 15 atrial flutters of the common type and 6 ectopic atrial tachycardias. In a total of 105 sessions 78 of the 83 patients were successfully treated with the use of radiofrequency current ablation. There were no significant procedure related complications. Radiofrequency current ablation can be carried out safely and successfully for the treatment of supraventricular tachycardia in young and adult patients with congenital heart disease. As such therapeutic strategy meets the specific requirements of this patient cohort, early consideration for this therapy is recommended.

We present a case of WPW syndrome with an accessory pathway in the right free wall. Two prolonged and failed attempts at radiofrequency catheter ablation of this accessory pathway in other institutions led to a third attempt in our hospital. With a 7F catheter in the right coronary artery, transient ischemia in the right ventricular myocardium developed with consecutive loss of bidirectional preexcitation within 45 seconds prior to catheter ablation. Removal of the guiding catheter, while the mapping catheter in the coronary artery was still in place, was reproducibly followed by the reoccurrence of the preexcitation pattern. Successful outcome of accessory pathway ablation was achieved by mapping the right free wall using an intracoronary catheter in the right coronary artery and ablating the accessory pathway using a modified long vascular sheet.

Prerequisite for successful radiofrequency catheter ablation on tachycardias is the exact mapping during the electrophysiologic study. The new mapping system CARTO allows a three-dimensional color-coded electroanatomic map of impulse propagation using electromagnetic technology. Mapping of sinuatrial activation in the right atrium of 11 patients represents the first clinical experience with this new system. The physiological activation sequence could be determined in all patients three-dimensionally, and the sinus node could be localized as a physiological activation focus with interindividual variability only in the sagital plane without complications. The nonfluoroscopic mapping system allows high resolution visualization of electrical activity and may therefore improve precision and simplify the determination of the arrhythmogenic substrate during tachycardias for successful catheter ablation.

Catheter ablation is a curative intervention for the treatment of supraventricular, but also ventricular, tachycardias that has proved both safe and effective. In patients with supraventricular tachycardias in underlying WPW syndrome or nodal tachycardia and appreciable symptoms, catheter ablation can be considered the treatment of choice. But many patients with monomorphic ventricular extrasystole that is difficult to control medically experience considerable subjective impairment in their daily life. It is possible that in such patients, too, catheter ablation may, sometime in the future, be used to cure their condition. However, long-term results must first be awaited.

Catheter ablation of the preexcitation syndrome is a curative treatment. Accessory pathways between structures of the specific conduction system or working myocardium are morphologic prerequisites for orthodromic or antidromic reentrant tachycardia of various frequency, duration, and rate. Detection of mechanisms of tachyarrhythmias and understanding the role of accessory pathways in tachycardia, mapping of accessory connections, function of nodal conduction system, and additional accessory pathways are necessary for successful catheter ablation. Anomalies of the tricuspid valve and coronary sinus and concomitant disease of the heart should be investigated prior to catheter ablation using echocardiography and contrast injection. Different variations of the preexcitation syndrome and the results of catheter ablation in 300 patients are demonstrated. Catheter ablation is indicated in refractory tachyarrhythmias on the basis of accessory pathways. The treatment is performed in a catheterization laboratory by two highly experienced cardiologists in the field of electrophysiology after training in 100 procedures. The investigators need experience in interventional treatment of coronary artery disease, in transseptal puncture, and in the management of complications (coronary and valvular problems, thromboemboly, and pericardial drainage). Catheterization needs careful protection of radiation. An ablation is possible at an atrial or ventricular insertion site of the accessory pathway or in between. Ablation is done during sinus rhythm, atrial stimulation, antidromic reentry, or atrial fibrillation or during ventricular pacing and orthodromic tachycardia. The procedure should end with bidirectional block of the accessory pathway in 90-95% of the patients. Complications occur in 2-4% of procedures. Recovery of accessory conduction is observed in 8%. Catheter ablation of the accessory pathway is the treatment of first choice in symptomatic patients with the pre-excitation syndrome. The procedure has limited risks and a high success rate.

Based on a case of a 72 year old woman with hemodynamically non-significant aortic stenosis. WPW-syndrome and out-of-hospital cardiac arrest, the diagnostic assessment and differential diagnosis of potentially fatal arrhythmias are discussed. In particular, the incidence of supraventricular and ventricular arrhythmias in patients with WPW-syndrome, their prognostic impact and therapeutic options are outlined.

In 1076 consecutive patients referred for radiofrequency current catheter ablation, the anatomical distribution and conduction properties of accessory pathways (APs) as well as the mode of recurrence after ablation were retrospectively analyzed and compared in patients with multiple and single APs. Except for 17 patients with Ebstein's anomaly, the prevalence of patients of multiple APs in this cohort was 5.4%. Patients with multiple APs. as opposed to patients with a single AP, had significantly more often APs located on the right free wall (23% versus 10%) and--since the prevalence of septal APs was identical in both groups--less frequently APs located on the left free wall (44% versus 56%). Also, concealed APs were significantly more often encountered in patients with multiple APs (45% versus 24%). Recurrence of conduction across an AP which had presumably been ablated was observed in both groups with statistically equal incidence of5%. In 11 patients with multiple APs, the additional AP was only found at the repeat session. These "new" APs were mostly concealed (9 out of 11) and necessitated an intervention predominantly late after the initial ablation session. Intermittent concealed conduction appears to be a likely explanation for this phenomenon. Patients with multiple APs exhibit a higher incidence of right free-wall and concealed APs, yet they stand the same, approximately 95%, chance of cure as do patients with a single AP. Nearly 25% percent of repeat sessions in patients initially thought to have a single AP are caused by the late manifestation of an additional AP.