Catheter ablation is a well-established treatment option for patients with ventricular arrhythmias. Recent advances in various imaging modalities, including three-dimensional electroanatomic mapping systems, magnetic resonance imaging, transesophageal and intracardiac echocardiography (ICE) have been adopted in catheter ablation of ventricular arrhythmias improving procedural outcome and safety. ICE is an imaging tool which provides real-time visualization of anatomical structures of the heart, facilitating catheter manipulation and navigation during ablation procedures. In this review we aim to highlight the benefits of ICE use in catheter ablation of ventricular arrhythmias and to describe practical techniques for visualization of cardiac structures with ICE during ventricular tachycardia ablations.

Several clinical, electrocardiographic (ECG) and electrophysiological markers have been proposed to provide optimal risk stratification in patients with Brugada syndrome (BrS). Of the different markers, only a spontaneous type 1 ECG pattern has clearly shown a sufficiently high predictive value. This review article highlights specific ECG markers based on depolarization and/or repolarization that have been associated with an increased risk of arrhythmic events in patients with BrS.

Red cell distribution width (RDW) and neutrophil-to-lymphocyte ratio (NLR) are simple hematologic indices that have been used to predict adverse outcomes in different clinical settings. The aim of our study is to determine whether RDW and NLR can predict atrial fibrillation (AF) recurrence in patients undergoing AF ablation. Consecutive patients, without known hematological disorders, who underwent AF catheter ablation between January 2014 and April 2017 were enrolled into this study. Blood samples were taken one day before and five hours after the ablation procedure. A total of 346 patients (224 males (65%), mean age: 59 ± 11 years old) were included. After a mean follow up of 26.2 ± 12.1 months, 80 (23.1%) patients experienced late AF recurrence (defined as any recurrence after the blanking period of three months), while 97 (28%) patients experienced early AF recurrence during the blanking period. Univariate analysis showed that early arrhythmia recurrence, type of AF and NLR after the procedure were significantly associated with late AF recurrence, while early arrhythmia recurrence and NLR remained significant in multivariate analysis. RDW was not associated with late AF recurrence. None of the parameters above predicted early arrhythmia recurrence. Simple and inexpensive hematological indices such as NLR should be evaluated for their ability to predict AF recurrence in patients undergoing catheter ablation in larger prospective studies.

The identification of patients prone to atrial fibrillation (AF) relapse after catheter ablation is essential for better patient selection and risk stratification. The current prospective cohort study aims to validate a novel P-wave index based on beat-to-beat (B2B) P-wave morphological and wavelet analysis designed to detect patients with low burden AF as a predictor of AF recurrence within a year after successful catheter ablation. From a total of 138 consecutive patients scheduled for AF ablation, 12-lead ECG and 10 min vectorcardiogram (VCG) recordings were obtained. Univariate analysis revealed that patients with higher B2B P-wave index had a two-fold risk for AF recurrence (HR: 2.35, 95% CI: 1.24–4.44, p: 0.010), along with prolonged P-wave, interatrial block, early AF recurrence, female gender, heart failure history, previous stroke, and CHA₂DS₂-VASc score. Multivariate analysis of assessable predictors before ablation revealed that B2B P-wave index, along with heart failure history and a history of previous stroke or transient ischemic attack, are independent predicting factors of atrial fibrillation recurrence. Further studies are needed to assess the predictive value of the B2B index with greater accuracy and evaluate a possible relationship with atrial substrate analysis.