2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias.

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Clinical impact of defibrillation testing at the time of implantable cardioverter-defibrillator insertion.

BACKGROUND: Ventricular fibrillation is routinely induced during implantable cardioverter-defibrillator insertion to assess defibrillator performance, but this strategy is experiencing a progressive decline. We aimed to assess the efficacy of defibrillator therapies and long-term outcome in a cohort of patients that underwent defibrillator implantation with and without defibrillation testing. METHODS: Retrospective observational series of consecutive patients undergoing initial defibrillator insertion or generator replacement. We registered spontaneous ventricular arrhythmias incidence and therapy efficacy, and mortality. RESULTS: A total of 545 patients underwent defibrillator implantation (111 with and 434 without defibrillation testing). After 19 (range 9-31) months of follow-up, the death rate per observation year (4% vs. 4%; p = 0.91) and the rate of patients with defibrillator-treated ventricular arrhythmic events per observation year (with test: 10% vs. without test: 12%; p = 0.46) were similar. The generalized estimating equations-adjusted first shock probability of success in patients with test (95%; CI 88-100%) vs. without test (98%; CI 96-100%; p = 0.42) and the proportion of successful antitachycardia therapies (with test: 87% vs. without test: 80%; p = 0.35) were similar between groups. There was no difference in the annualized rate of failed first shock per patient and per shocked patient between groups (5% vs. 4%; p = 0.94). CONCLUSIONS: In this observational study, that included an unselected population of patients with a defibrillator, no difference was found in overall mortality, first shock efficacy and rate of failed shocks regardless of whether defibrillation testing was performed or not.

Sustained ventricular tachycardia in structural heart disease.

Ventricular arrhythmias are responsible for the majority of sudden cardiac deaths (SCD), particularly in patients with structural heart disease. Coronary artery disease, essentially previous myocardial infarction, is the most common heart disease upon which sustained ventricular tachycardia (VT) occurs, being reentry the predominant mechanism. Other cardiac conditions, such as idiopathic dilated cardiomyopathy, Chagas disease, sarcoidosis, arrhythmogenic cardiomyopathies, and repaired congenital heart disease may also present with VT in follow-up. Analysis of the 12-lead electrocardiogram (ECG) is essential for diagnosis. There are numerous electrocardiographic criteria that suggest VT with good specificity. The ECG also guides us in locating the site of origin of the arrhythmia and the presence of underlying heart disease. The electrophysiological study provides valuable information to establish the mechanism of the arrhythmia and guide the ablation procedure, as well as to confirm the diagnosis when dubious ECG. Given the poor efficacy of antiarrhythmic drug therapy, adjunctive catheter ablation contributes to reduce the frequency of VT episodes and the number of shocks in patients implanted with a cardioverter-defibrillator (ICD). ICD therapy has proven to be effective in patients with aborted SCD or sustained VT in the presence of structural heart disease. It is the only therapy that improves survival in this patient population and its implantation is unquestioned nowadays.