[Non-fluoroscopic catheter tracking: the MediGuide™ system]. / Nicht fluoroskopische Katheternavigation: das MediGuide™-System.

Conventional fluoroscopy is the main technology for intracardiac device tracking in interventional cardiovascular procedures. For therapy delivery it carries the advantage of being able to instantaneously localize the device and its spatial relationship with respect to the moving target organ. However, besides the associated X-ray exposure, fluoroscopy only provides 2D orientation. For treatment of complex cardiac anatomies and substrates such as in interventional electrophysiology, 3-D mapping technologies have been introduced to facilitate spatial, anatomic, and electrical orientation. A new technological platform (MediGuide(™)) offers the option to continuously display the catheter tip on a prerecorded cine-loop allowing better anatomic understanding of the underlying substrate. We describe our initial experience using the system with diagnostic catheters only and the first procedures with the MediGuide(™) equipped ablation catheter (available since May 2012). We could show a significant decrease of fluoroscopy time in all types of procedures with comparable procedure times. No increase in complication rates was observed.

[Recommendations of the Working Group of Arrhythmias of the German Society of Cardiology on the approach to patients with Riata® and Riata ST® leads (St. Jude Medical). Nucleus of the Working Group of Arrhythmias of the German Society of Cardiology]. / Empfehlungen der Deutschen Gesellschaft für Kardiologie (Arbeitsgruppe Rhythmologie) zum Umgang mit Patienten mit ICD-Elektroden Riata® und Riata ST® der Firma St. Jude Medical. Nucleus der AG Rhythmologie der Deutschen Gesellschaft für Kardiologie.

Riata® and Riata ST® implantable cardioverter defibrillator (ICD) leads (St. Jude Medical, Sylmar, CA) show an increased incidence of insulation defects, particularly "inside-out" lead fracture where inner, separately insulated cables penetrate through the surrounding silicone of the lead body. The exact incidence of Riata® lead problems is not clear and seems to range between 2-4% per year in the first 5 years after implantation according to new registry data. We recommend beyond a detailed information the following care of patients with Riata® and Riata ST® leads: 1) Activation of automatic ICD alerts, 2) remote monitoring with automatic daily alerts whenever possible, 3) monthly ICD controls in patients at high risk (pacemaker dependency, history of ventricular tachyarrhythmias) and high or moderate lead-related risk (8F, 7F single coil), 3-monthly controls in moderate patient and lead-related risk, 3 to 6-monthly controls in low patient and lead-related risk (no bradycardia, no history of ventricular tachyarrhythmia). Every ICD control should include meticulous analysis of oversensing artifacts in stored electrograms (EGMs) of sustained and non-sustained ventricular tachyarrhythmias and registration of EGMs during provocation testing (pectoral muscle activity, arm movements). If electrical abnormalities are observed, reoperation with addition of a new ICD lead is recommended; lead extraction only if indicated according to current guidelines. Fluoroscopy should only be performed if electrical abnormalities are found by an experienced electrophysiologist and a high frame rate and resolution. Management of fluoroscopic abnormalities in the absence of electrical abnormalities is not clear. Therefore, routine fluoroscopy of patients with Riata® leads without electrical abnormalities is not recommended.

Role of the coronary sinus ostium musculature in reentrant formation.

BACKGROUND: Radiofrequency ablation of focal atrial tachycardias (AT) is a validated technique with high success rates. However, electrophysiological (EP) characteristics and ablation strategy of localized reentrant AT originating from the coronary sinus ostium (CSo) have not been reported in detail so far. METHODS: From January 2009 to July 2010, 1,453 patients underwent clinically motivated EP studies. Four patients were diagnosed with localized reentrant AT originating from the CSo. P wave morphology and consistency of tachycardia cycle length were studied. Subsequently, if reentry was suggested as an underlying mechanism for AT, color-coded 3-dimensional (3D) entrainment mapping was performed to localize the reentrant circuit or differentiate a localized reentrant AT from macroreentant AT, and also confirm reentry as an underlying mechanism of AT by evaluating consistency of return cycles after entrainment at multiple sites in both atria. Finally, activation mapping was performed to localize the earliest activation site. RESULTS: The P wave morphologies and isoelectric line between the P waves suggested most likely an AT originating from the CSo with a centrifugal activation pattern, which was confirmed by activation mapping. Consistency of return cycles and continuously fragmented local electrograms at successful ablation sites suggested reentry as an underlying AT mechanism. Color-coded 3D entrainment mapping in all 4 patients located the reentrant circuit in the CSo. There were also two specific features observed. One was fragmented and/or double potentials recorded in the CSo with prominent prolonged electrogram duration compared to those during sinus rhythm. The other is a significant conduction delay within the CS. The myocardium of the CSo was suggested as a part of the critical isthmus within the reentrant circuit, while the rest of atria distal to the CSo and myocardial coat of the distal CS were not involved in the tachycardia circuit, which was confirmed by entrainment mapping. CONCLUSION: Although CSo myocardium has been implicated to be a part of atrioventricular nodal reentrant tachycardia, to the best of our knowledge, this is the first report showing the localized reentrant AT confined to the CSo. Three of our patients (75%) had concomitant atrial fibrillation (AF). Further studies should be warranted to clarify the role of AT from the CS in triggering AF.

Management of patients pre-, per- and postcatheter ablation procedures: how to minimize complications?

Catheter ablation using radiofrequency energy has become an accepted and safe treatment of cardiac arrhythmias. Nevertheless, it is important to determine the risk-to-benefit ratio of a specific procedure, especially when treating subjects with non-life-threatening cardiac arrhythmias, such as AV-nodal reentrant tachycardia or atrial fibrillation, and efforts have to be made to reduce the incidence of complications associated with these procedures, which are in the vast majority of cases not directly attributable to RF energy application but rather with obtaining peripheral vascular access or intracardiac catheter manipulation. Although complication rates in atrial fibrillation (AF) ablation have decreased with improvements of the ablation technique and a change of ablation concepts since the introduction of this technique, the risk of complication is still considerable and significantly higher compared to ablation procedures of other supraventricular tachycardia, including potentially life-threatening events. The higher incidence of AF ablation associated complications may be explained by the complex technique, the need for trans-septal puncture or extensive manipulation in the thin walled left atrium, as well as possible adverse effects of sedation. Even "new" complications associated with AF catheter ablation were identified, such as pulmonary vein stenosis or atrio-esophageal fistula formation. This article will review general risks and complications that can occur during RF catheter ablation procedures and conscious sedation with a particular attention on AF ablation procedures.

[Remote control in ICD therapy]. / Telemedizin in der ICD-Therapie.

In several studies, ICD therapy has been shown to be an effective treatment option for patients suffering from or being at risk of malignant ventricular arrhythmias. Given the increasing rate of ICD implantations with the need for in-office interrogations at least twice a year, the number of follow-up visits is constantly growing. Remote transmission of relevant ICD data is a way to reduce follow-up burden for the physician, travel costs for the patient, and the time delay between onset of medical or device problems and an adequate physician response. In several studies, it has been demonstrated that remote ICD follow-up is safe and reduces follow-up resources for both the patient and the physician. With ongoing studies, the questions of whether remote ICD interrogations can offer additional diagnostic and therapeutic options that go beyond pure device follow-up and allow for a more complex management of ICD patients, who in fact represent a large percentage of the heart failure population, will have to be answered.

[Analysis of intracardial electrograms in pacemakers and ICD systems by Biotronik]. / Analyse intrakardialer Elektrogramme in Schrittmachern und ICDs der Firma Biotronik.

Detailed analysis of stored electrograms is essential for the interpretation of arrhythmias, programming changes, and optimization of the medical therapy in patients with implanted pacemakers and defibrillators. The physician who cares for patients with implantable electrical devices has to be able to understand the detection and treatment algorithms of those devices. Biotronik pacemakers of newer generations are capable of storing intracardiac electrograms. Earlier devices store up to 12 electrograms of 10 s duration after certain trigger events, like atrial tachycardia or high ventricular rates. Cardiac resynchronization systems can store electrograms after patient activation with magnets in addition to the above mentioned trigger-activated electrograms. Defibrillators store intracardiac electrograms during tachycardia episodes with near-field and far-field electrograms of the right ventricular lead in addition to the markers in single and dual chamber defibrillators (in addition to an atrial electrogram) and near field electrograms of the atrial, the right, and the left ventricular electrode in addition to the markers in resynchronization systems. Each channel has a maximum storing capacity of 32 min. If there are more episodes than storing capacity, electrograms of older episodes will be overwritten, but if the newer episodes are all classified as supraventricular, the last two ventricular episodes (VT or VF) will remain in the episode memory. This article describes stored electrograms, detection, and treatment algorithms of implantable cardiac devices manufactured by Biotronik.

[Atrial fibrillation. New aspects for diagnosis and follow-up]. / Vorhofflimmern. Neue Aspekte für Diagnostik und Follow-up.

Continuous rhythm monitoring is the gold standard of objective rhythm assessment in patients with atrial fibrillation, thus, facilitating accurate detection of symptomatic and asymptomatic atrial fibrillation. This is of scientific and clinical interest for the understanding of this arrhythmia, the establishment of evidence-based therapeutic approaches, the definition of clinically indicated monitoring strategies, and for decision-making about oral anticoagulation. This article illustrates the importance of continuous monitoring of atrial fibrillation and presents developing technologies with their advantages and limitations as well as initial clinical experience.

Atrial fibrillation in the elderly.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and its prevalence is increasing with age. With aging of the population treatment of atrial fibrillation especially in elderly population is a growing task for all medical staff working with elderly patients. Treatment of atrial fibrillation especially in elderly patients has to focus on prevention of thromboembolism as well as symptom relief with rate or rhythm control. This review article will focus on medical and non-pharmacological treatment options for the treatment of atrial fibrillation in elderly patients.

Epicardial versus transvenous left ventricular lead placement in patients receiving cardiac resynchronization therapy: results from a randomized prospective study.

BACKGROUND: The aim of this prospective study was to determine the differences in left ventricular (LV) lead positioning for cardiac resynchronization therapy (CRT): comparing a percutaneous transvenous approach via the coronary sinus versus epimyocardial placement via a left lateral mini-thoracotomy. METHODS: Eighty consecutive patients with symptomatic left ventricular dysfunction and an indication for CRT were randomized to receive either a transvenous (n = 40) or epicardial (n = 40) LV-lead placement. Postoperative follow-up included assessment of NYHA functional class, ECG and echocardiography. RESULTS: The transvenous group had a shorter ICU stay (0.66 vs. 3.8 days) and shorter ventilation times (0.34 vs. 3.2 h). The epicardial group had less exposure to radiation (7.4 vs. 23 min) and required less use of contrast medium (3.24 vs. 61 ml). At 6 months follow-up, no major differences in LV-lead parameters (threshold, sensing, and impedance) were observed. CONCLUSION: Both epicardial and transvenous LV-lead placement for CRT therapy are safe and effective. The transvenous approach is less invasive and should be considered the standard procedure for patients without renal insufficiency. However, in a case of difficult coronary venous anatomy with the inability to position the lead as desired, epicardial LV-lead placement remains an alternative option.

Radiofrequency ablation of accessory pathways. Contemporary success rates and complications in 323 patients.

INTRODUCTION: 17 years ago the first radiofrequency catheter ablation of an accessory pathway (AP) was performed. The aim of this study was to describe the contemporary success rates and procedure related complication rates of radiofrequency (RF) ablation of accessory pathways (APs). In addition, the present study describes the anatomical distribution of APs according to the new nomenclature introduced by NASPE and ESC in 1999. METHODS: The analysis included all patients, who underwent RF ablation of an AP in the Heart Center Leipzig between January 2000 and December 2003. RESULTS: Over a 4 year period 336 APs were ablated in 323 patients. 201 APs (60%) presented with antegrade and retrograde conduction and showed preexcitation on ECG. For the remaining 135 APs (40%), only retrograde conduction over the AP was documented. According to the new nomenclature APs were classified as left-sided, right sided, septal and paraseptal APs. 188 APs (56%) were located on the left, 41 (12%) on the right, 64 (19%) in the paraseptal space and 31 APs (9%) presented with a septal or parahisian localization, respectively. Because of atypical course and/or characteristics 12 APs (4%) could not be classified. Ablation of all pathways were successful in 315 patients (98%). In 289 patients (89%) success was achieved within a single ablation session. The left-sided pathways had a re-intervention rate of 5%, which was significantly lower compared to the remaining localizations. The highest re-intervention rate was observed in the septal APs (23%). Complications were observed in less than 2% of all treated patients. CONCLUSIONS: 17 years after the first RF catheter ablation of an AP this therapy is established as a highly effective procedure. The success rate has improved to 98% and the complication rate has been minimized to less than 2%. The most frequent localization of APs is left posterior. Left sided APs also presented with the lowest re-intervention rate. The introduction of the new nomenclature in 1999 by NASPE and ESC has simplified the description of the exact anatomical localization of an AP.