[Epicardial VT ablation : In whom, when, how and why?] / Epikardiales Mapping und Ablation bei ventrikulären Tachykardien : Bei wem, wann, wie und mit welchen Erfolgsaussichten?

Ventricular tachycardia (VT) is a leading cause of cardiovascular death and remains the main cause of sudden cardiac death. Implanted cardiac defibrillators (ICD) improve survival but the recurrent ICD therapies, mostly ICD shocks, are associated with an increased mortality and deleterious psychological effects. In this regard and based on the results of multicenter studies, the current European guidelines recommend early referral for catheter ablation. The ablation strategy (isolated endocardial approach or combined epi-/endocardial) depends mostly on the underlying myocardial disease. Thus, almost all patients with right ventricular dysplasia and Chagas disease, the majority of those with dilative cardiomyopathy, and some patients with ischemic cardiomyopathy (mostly posterior wall infarction or large transmural anterior wall infarction) have an epicardial scar as the underlying substrate for recurrent VT episodes. Thus, in this group of patients, isolated endocardial VT ablation may be associated with an increased VT recurrence and therefore an epicardial approach is also needed. Cardiac imaging (cardio-CT/MRI with late enhancement[MRI LE]) can reliably identify the distribution and characteristics of the myocardial scar and may be helpful in planning the ablation strategy. When performed in highly specialized centers, epicardial catheter ablation of VT leads to a significant reduction of recurrent VT episodes compared to the endocardial VT ablation alone and with lower complication rates.

[Epicardial ablation of ventricular tachycardias]. / Epikardiale Ablation ventrikulärer Tachykardien.

Ventricular tachycardias (VT) in patients with structural heart diseases have predominantly a scar-associated reentry mechanism so that substrate-based ablation approaches also have to be used in nearly all procedures. In many VT cases-especially in nonischemic cardiomyopathy (NICM) and arrhythmogenic right ventricular cardiomyopathy-a critical epicardial substrate can be identified as an essential component of the reentry circuit so that for the ablation-based modification of the substrate in these cases an epicardial approach is necessary. In cases of redo-VT ablation procedures in ischemic cardiomyopathy (after a previously endocardial ablation), an epicardial approach should also be considered. There are also cases in whom no endocardial substrate can be identified and an isolated epicardial substrate can be identified. Worldwide epicardial VT ablations are usually performed after gaining epicardial access using subxyphoidal puncture. The results of recent studies show a higher efficiency with stabilization of cardiac rhythm and reduction of recurrent VT episodes (about 70% event-free survival at the 2­year follow-up) after endo-plus epicardial substrate modification. In electrical storm cases, an early epicardial VT ablation approach also appears to be relevant, especially in NICM. Epicardial instrumentation and ablation represents a complex procedure which should only be performed in experienced centers with cardiac surgery back-up. In these experienced centers, the complications rate is less than 5%.

[Interventional electrophysiology in cardiac MRI : what is the current status?]. / Interventionelle Elektrophysiologie in der kardialen MRT : Wie ist der aktuelle Stand?

The ablation of simple and complex cardiac arrhythmias has become a first-line therapy in interventional cardiology and is mainly guided by conventional fluoroscopy. Cardiac magnetic resonance imaging (cMRI) allows exact three-dimensional (3D) visualization of complex anatomical structures and serves in the planning and implementation of ablation procedures. Post-procedural lesion visualization using cMRI can assess the success of ablation therapy and may distinguish potential complications. Performing ablation directly in the MRI scanner, with the option of anatomical substrate imagining, exact catheter navigation and real-time lesion visualization, holds the promise of improving success rates and safety in the interventional therapy of simple and complex arrhythmias.

[Pulmonary embolism: clinical relevance, requirements for diagnostic and therapeutic strategies]. / Lungenembolie: Klinische Bedeutung, Anforderung an die Diagnostik und Behandlungsoptionen.

In the population the annual incidence of pulmonary embolism amounts to 1.3-2.8 per 1000 at the age of 65-89 years. Mortality reaches about 17% within the first 3 months. Acute pulmonary embolism is characterized by an increase in pulmonary arterial pressure and an impairment of the pulmonary gas exchange. Elevation of the right cardiac pressure up to right heart decompensation may follow. In addition, hypoxemia, hyperventilation, dead space ventilation, right to left shunting, bronchoconstriction, and vasoconstriction may occur. Clinical examination, ECG, laboratory findings such as elevated D-dimer, blood gas analysis, ultrasound examination of the veins of the lower extremities, and transthoracic echocardiography are acutely available diagnostic methods of an emergency department. In addition, extensive diagnostic procedures like pulmonary scintigraphy and pulmonary angiography may be required. The aim is to get a definite diagnosis as quickly as possible to direct therapy. In acute pulmonary embolism with cardiac shock, monitoring and stabilization of the circulatory function as well as an appropriate anticoagulant therapy are essential. In some cases surgery or a local fibrinolytic intervention is indicated.

[TEE-guided cardioversion in patients with atrial fibrillation without previous anticoagulation]. / TEE-geführte Kardioversion bei Patienten mit Vorhofflimmern ohne vorherige Antikoagulation.

A total of 332 patients (mean age 65+/-10 years, 86 female) with nonvalvular atrial fibrillation (AF) of more than 48 hours duration and lack of a sufficient anticoagulation were included. After exclusion of thrombotic material in the left atrium using transesophageal echocardiography (TEE) cardioversion (CV) was performed within 24 hours. At the same time oral anticoagulation (AC) (overlapping with PTT-affecting heparinisation) was started. If thrombi were found by TEE, the examination was repeated after at least four weeks of anticoagulation. If thrombi were absent at this time, CV was performed. Periprocedural embolism was defined as primary endpoint, whereas the detection of atrial thrombi before CV was defined as secondary endpoint. In 33 of the 332 Patients (9.9%) the TEE showed a thrombus in the left atrium respectively the left atrial appendage (n=22) or thrombi could not be excluded (n=11). 383 TEEs were performed without complications in an overall of 332 patients.A total of 305 CV were performed (electrical n=300, pharmacological n=5) and during periprocedural monitoring and in the time of four weeks after CV no thromboembolic complications were observed.TEE-guided CV in patients with AF persisting for more than 48 hours and without previous AC can be considered as a method that is both safe and effective.