Herzschrittmachertherapie und Elektrophysiologie最新文献

The two currently available leadless pacemakers are highly effective and safe in the respective approval studies and also real-world registries. Compared to conventional pacemakers, there are lower long-term complication rates compared to conventional pacemaker systems (especially regarding lead dislocations and systemic infections). Increasing evidence (currently largely for the Micra™ [Medtronic, Minneapolis, MN, USA] device) shows that these advantages are also valid in the long-term. Leadless pacemakers can therefore be regarded a "permanently good solution", when appropriately implanted in suitable patients.

Electrical storm due to recurrent ventricular tachycardias (VTs) is a life-threatening arrhythmic emergency. The authors present a case report of a 69-year-old male patient with VT storm of non-ischemic etiology. Despite optimal medical treatment escalated by amiodarone antiarrhythmic drug therapy, the patient experienced multiple implantable cardioverter defibrillator (ICD) shocks. An electrophysiological study revealed an epicardial substrate; however, considering the patient's extreme obesity and active anticoagulant effect, catheter ablation was deemed to be unfeasible. Subsequently, mexiletine was added to the patient's drug regimen, resulting in successful control of arrhythmias during the following 6 months. Although the most recent European guidelines for the management of patients with ventricular arrhythmias mention mexiletine only for the treatment of LQT3 patients, its use for treatment-refractory VT storm seems to also be an important indication area.

Atrial loss of capture in the chronic phase after implantation may be permanent due to various causes, e.g. technical lead problems or increased scar tissue formation around the lead tip. However, it may also be transient after atrial ischemia in the context of occlusion of the right coronary artery. In this case, it may be preferable to wait for recovery, which may take up to 45 days, instead of immediately performing an atrial lead revision.

Background: Atrioventricular-nodal reentrant tachycardia (AVNRT) is a common supraventricular tachycardia, particularly in younger patients. The treatment of choice is radiofrequency catheter ablation (RFCA), traditionally necessitating ionizing radiation for catheter guidance.

Objective: The authors aimed to demonstrate the feasibility and safety of zero-fluoroscopy RFCA of AVNRT using EnSite™ NavX™ as a three-dimensional (3D) electroanatomical mapping system (EAM).

Methods: The authors retrospectively analyzed 68 patients that underwent AVNRT-RFCA. One group was a priori allocated to conventional fluoroscopy mapping (convFluoro, n = 30). In 38 cases, the electrophysiologist chose to use 3D-EAM for ablation. Of these patients, 20 could be ablated without fluoroscopy use (zeroFluoro). In 18 cases that were initially intended as 3D-EAM, additional fluoroscopy use was necessary due to difficult anatomic conditions (convertedFluoro). Procedure duration, fluoroscopy duration and dose, as well as complications were analyzed.

Results: Procedure duration was similar for the convFluoro and zeroFluoro groups (74 ± 24 min vs. 80 ± 26 min, p = ns). The convertedFluoro group showed longer procedure duration compared to the convFluoro group (94 ± 30 min vs. 74 ± 24 min, p < 0.05). The use of 3D-EAM significantly reduced fluoroscopy duration comparing the convFluoro with the convertedFluoro group (12 ± 9 min vs. 7 ± 6 min, p < 0.05). The difference in fluoroscopy dose between convFluoro and convertedFluoro did not reach significance (169 ± 166 cGycm² vs. 134 ± 137 cGycm², p = ns). In zeroFluoro cases, no radiation was used at all. 3D-EAM-guided RFCA was primarily successful in all patients. Overall, there were only few minor complications in the different groups. No major complications occurred.

Conclusion: Zero-fluoro RFCA in patients with AVNRT is feasible and safe. 3D-EAM can reduce radiation exposure in the majority of patients without prolonging procedure duration or increasing complications.

Lead extraction due to infection or lead dysfunction has become more important in recent years. Patients with high risk of severe and life-threatening complications should only undergo surgery in experienced centers where appropriate personnel and equipment are available. In this review, different techniques and methods to safely and successfully perform transvenous lead extraction are summarized.

Ablation is an established treatment option for atrial fibrillation (AF) and is associated with convincing success rates and a reasonable safety profile. Ablation strategies going beyond pulmonary vein isolation in patients with chronic forms of AF are less well established and reproducible. Especially in patients with progressed AF forms multiple ablation procedures might be mandatory to achieve reasonable clinical success. An early ablation strategy might stop or prolong the progress from paroxysmal to persistent AF. In addition, ablation is more effective than drug-based treatment and comparably safe. Long-term success rates after a single and after multiple ablation procedures in paroxysmal AF are reported with 60-70% and up to 80%, while success rates in persistent or long-standing persistent AF are less favorable (single procedure 40-50%, multiple procedures 70%). However, currently non-recurrence of AF is the most established but potentially not the best endpoint. The burden of AF after ablation as assessed by novel monitoring modalities might gain further clinical importance.

In recent years, imaging techniques have improved enormously. This leads to a decrease in stress testing indication for diagnosis and management of coronary artery diseases. However, stress testing remains an indispensable diagnostic tool for assessing patients' physical activity and their circulatory behavior during exercise. Using stress testing helps to assess patients' heart rate behavior or even to detect or trigger cardiac arrhythmias, for example, assessment of chronotropic competency, tachycardia-triggering or detection of a sudden heart rate drop with relevant bradycardia. The present review focuses on the assessment of stress testing in rhythmology. Since abnormal findings, which may indicate the presence of coronary heart disease, may occur during exercise testing, relevant ischemic criteria are also briefly addressed.

Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia in patients with accessory pathways (AP) are common supraventricular tachycardias. High long-term efficacy of about 97% (AVNRT) and 92% (AP) has been observed in children and adults. The risk of occurring atrioventricular block is low (0.4-0.8% during AVNRT, 0.1-0.2% for AP). Catheter ablation shows a lower efficacy of 87-93% and elevated atrioventricular block risk up to 10% in patient groups with complex congenital heart disease. Nonsynchronized ventricular activation during preexcitation or permanent reentrant tachycardias can induce heart failure, and remission of left ventricular function can be expected in > 90% after successful catheter ablation. Therefore, catheter ablation is the long-term therapy of choice for AVNRT and AP with high efficacy and safety for most patient populations.