Expert consensus on acute management of ventricular arrhythmias - VT network Austria.

The Arrhythmia Working Group of the Austrian Society of Cardiology (ÖKG) has set the goal of systematically structuring and organizing the acute care of patients with ventricular arrhythmias (VA), i.e. ventricular tachycardia (VT) or ventricular fibrillation (VF) in Austria. Within a consensus paper, national recommendations on the basic diagnostic work-up of VA (12-lead ECG, medical history, family history, laboratory analyses, echocardiography, search for reversible causes, ICD interrogation), as well as further medical treatment and therapeutic measures (indication of coronary angiography, ablation therapy) are established. Since acute ablation of VT is indicated in the current ESC guidelines as a class IB indication for scar-associated incessant VT or electrical storm (ES; ≥ 3 ICD therapies in 24 h) as well as for ischemic cardiomyopathy (iCMP) with recurrent ICD shocks, organizational measures must be taken to ensure that these guidelines can be implemented. Therefore, a VT network will be established covering all areas in Austria, consisting of primary and secondary VT centers. Organizational aspects of an acute VT network are defined and should subsequently be implemented by the participating hospitals. All electrophysiologic centers in Austria that deal with VT ablation are to be integrated into the network in the medium-term. Centers that co-operate in the network are divided into primary and secondary VT centers according to predefined criteria.

[Perioperative management of patients with implanted pacemakers or cardioverter/defibrillators. Recommendations of the Austrian Society for Anaesthesiology, Resuscitation and Intensive Care Medicine, the Austrian Society for Cardiology and the Austrian Society for Surgery]. / Perioperatives Management von Patienten mit implantiertem Schrittmacher oder Kardioverter/Defibrillator. Empfehlungen der Osterreichischen Gesellschaft für Anästhesiologie, Reanimation und Intensivmedizin, der Osterreichischen Kardiologischen Gesellschaft und der Osterreichischen Gesellschaft für Chirurgie.

The perioperative risk for patients with pacemakers or implanted cardioverter/defibrillators (ICD) is mainly dependent on the underlying disease. However, severe to life-threatening complications of the implanted system can occur due to electromagnetic interference in the environment of the operation. These complications can be prevented or adequately treated by taking special precautions and measures. Even though the currently available data on the optimal perioperative management to pacemakers and ICDs is still unsatisfactory, the increasing clinical relevance of this topic was the reason for the formulation of recommendations by an interdisciplinary working group in Austria.

Simultaneous angiographic imaging of ipsilateral pulmonary veins for catheter ablation of atrial fibrillation.

Various imaging techniques are nowadays in clinical use to obtain important information about pulmonary vein (PV) anatomy in patients undergoing catheter ablation of atrial fibrillation (AF). Although some controversy exists about the optimal approach for catheter ablation of AF in recent times, knowledge of the individual left atrial-PV anatomy remains a basic feature of the different ablational techniques. Angiographic delineation of PV ostia has become an integral part of the PV isolation procedure, mainly in order to avoid potentially harmful PV stenosis. Selective venography with angiocatheters is well documented and widely available but has its own limitations, particularly with respect to visualization of the atriovenous junctions. The present report summarizes the usefulness, safety and feasibility of a new angiographic technique for simultaneous imaging of ipsilateral PVs applicable during catheter ablation of AF. Electrophysiologically guided segmental PV isolation was accomplished in 31 patients mostly with paroxysmal atrial fibrillation, who experienced significant clinical improvement during a followup of 17 +/- 15 months. The angiographic technique was effective for assessment of the individual anatomy including common ostia and supernumerary veins which can be easily missed by selective venography. Variant PV ostia were identified in about 20% of patients; particularly the presence of a left common trunk was challenging for the segmental ablation strategy. Angiographic detection of variant PV anatomy was comparable to visualization with computer tomography performed at 4-months follow-up. Finally, this type of angiographic imaging performed at the time of catheter ablation may help to reduce the risk of significant PV stenosis.

Relationship of QT interval duration with carotid intima media thickness in a clinically healthy population undergoing cardiovascular risk screening.

OBJECTIVES: To investigate the relationship between cardiac repolarization (QT interval duration) and intima media thickness (IMT) of the carotid arteries as surrogate measures of subclinical atherosclerosis. DESIGN: Prospective study with consecutive subjects enrolled in the SAPHIR program (Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk). SETTING: The analysis of the material was performed at the departments of medicine and neurology of a university hospital. SUBJECTS: The study cohort comprises a population-based sample of 1199 clinically healthy subjects (851 men and 348 women; age 39-66 years). Exclusion criteria were cardiovascular disease, diabetes, atrial fibrillation, bundle branch block and use of medication affecting QT interval duration. MAIN OUTCOME MEASURES: IMT of common (CCA) and internal carotid arteries (ICA) was measured by B-mode ultrasound. QT interval duration was determined in the resting 12-lead electrocardiogram by an automatic analysis program. The QT intervals were corrected for heart rate with five standard equations (QTc-Bazett, -Fridericia, -Framingham, -Hodges and -Rautaharju) and tested for their relationship with carotid IMT after adjustment for clinical and metabolic variables. Results. Females had higher heart rates than males (64 +/- 10 b min(-1) vs. 60 +/- 9 b min(-1), P <0.0005), with longer mean QT (410 +/- 28 ms vs. 404 +/- 28 ms, P=0.003) and QTc intervals in all correction formulae (P <0.0005). Significant correlations between QT/QTc and ICA IMT (r=0.14-0.16) were found in males. In the general linear model the association between QTc (except for Bazett) and ICA IMT remained significant after adjusting for age, BMI and further cardiovascular risk factors. In females the crude correlations between QT/QTc and ICA IMT were lower than those with CCA IMT. Only the correlation between uncorrected QT and CCA IMT (r=0.15, P=0.006) remained significant after adjustment for covariates. CONCLUSIONS: The results of the present study demonstrate that QT and QTc prolongation are in part associated with IMT of carotid arteries, which is an established risk marker of subclinical atherosclerosis. In men the data support the hypothesis of an association between QTc and ICA IMT. In women a statistically significant relationship was found between the uncorrected QT interval and CCA IMT. These findings suggest that differences in carotid IMT and ventricular repolarization between genders might be related to hormonal and nonhormonal effects.

Ablation of postinfarction ventricular tachycardia guided by isolated diastolic potentials.

Frequent recurrences of ventricular tachycardia (VT) despite implantable cardioverter-defibrillator (ICD) and antiarrhythmic drug therapy are a typical indication for catheter ablation. We performed endocardial mapping of an haemodynamically tolerated VT in a 67-year-old male patient. Isolated diastolic potentials (IDPs) of similar morphology were recorded during atrial paced rhythm at baseline and during monomorphic VT. The isolated potentials were required for initiation and maintenance of ventricular arrhythmia. These diastolic electrograms were considered to be part of the reentry circuit, as they remained constantly associated with VT during oscillations of cycle length and resetting. Validation of the ablation target was not performed by exact entrainment pacing in order to test the predictive value of the observed diagnostic phenomena. Radiofrequency (RF) energy applications were successful at the site where IDPs were recorded during atrial paced rhythm and VT. Ablation decreased the need for ICD therapies effectively in a patient with scar-related, slow VT.

Radiofrequency ablation of focal atrial tachycardia and atrioatrial conduction from recipient to donor after orthotopic heart transplantation.

After cardiac transplantation, atrial arrhythmias may develop in the residual recipient atrium and conduct to the donor heart. Radiofrequency (RF) ablation of the atrioatrial conduction may be effective in arrhythmia control, although the recipient atrium continues its tachycardia. We hypothesize that in patients with posttransplant atrial tachycardia, it is possible to ablate both the arrhythmogenic focus in the recipient atrium and the atrioatrial conduction. A 47-year-old patient who had orthotopic heart transplantation 9 months earlier underwent RF ablation procedure because of medically uncontrolled atrial arrhythmia. By conventional electrophysiologic mapping, we localized the focus of the atrial tachycardia in the recipient atrium and the electrical atrioatrial connection across the anastomotic suture line. Selective applications of RF energy eliminated both targets successfully. RF ablation of recipient atrial tachycardia and atrioatrial conduction from recipient to donor may lead to long-term success of arrhythmia control.