Combining contact force and local impedance to treat idiopathic premature ventricular contractions from the outflow tracts: impact of ablation strategy on outcomes.

Background: Contact force (CF)-sensing catheters have not proved superior to standard catheters in the ablation of premature ventricular contractions (PVCs) from the right and left ventricular outflow tract (RVOT, LVOT). In this context, the utility of measuring local impedance (LI) is not known. We aimed to ascertain whether the use of a catheter combining LI and CF information was associated with superior outcomes in comparison with other catheter technologies.

Prospective evaluation of local impedance drop to guide left atrial posterior wall ablation with high power.

Background: Local impedance (LI) drop predicts acute conduction block during pulmonary vein isolation (PVI). Whether the LI drop predicts also the achievement of left atrial posterior wall isolation (LAPWI) in persistent atrial fibrillation (PersAF) patients is unknown. We evaluated the efficacy and the safety of LI drop-guided LAPW ablation by using high power (50 watts) and investigated the impact of ablation parameters on the LI drop.

Targeted ablation of residual pulmonary vein potentials in atrial fibrillation ablation through ultra-high-density mapping: Insights from the CHARISMA registry.

Introduction: Low-voltage activity beyond pulmonary veins (PVs) may contribute to the failure of ablation of atrial fibrillation (AF) in the long term. We aimed to assess the presence of gaps (PVG) and residual potential (residual antral potential [RAP]) within the antral scar by means of an ultra-high-density mapping (UHDM) system.

Methods: We studied consecutive patients from the CHARISMA registry who were undergoing AF ablation and had complete characterization of residual PV antral activity.

High-density mapping and ablation of an incessant ventricular tachycardia with endo-epicardial involvement in a patient with situs inversus totalis and left ventricular noncompaction.

The association of situs inversus totalis and left ventricular noncompaction is very rare and poses several and unique challenges if endo-epicardial ablation has to be performed, both for anatomical access to the target area and for arrhythmia complexity. We report a case of incessant ventricular tachycardia with endo-epicardial involvement that required ablation in both surfaces to obtain final noninducibility.

Localized reentry in the superior vena cava giving rise to an atypical right atrial flutter: Insights from an analysis of two cases.

The superior vena cava is a known arrhythmogenic structure since it can be a non pulmonary vein focus of atrial fibrillation but also a source of fibrillatory activity that in some cases has been reported to mimick atrial flutter. In this report, we demonstrate that another arrhythmogenic mechanism from this vein, that is localized reentry, can cause a specific pattern of atypical right flutter.

How to unmask septal local abnormal ventricular activities with the new LUMIPOINT software.

We report the use of the new automated tool Lumipoint for the detection of LAVA (local abnormal ventricular activities) when they are buried within the far-field ventricular signal, especially in regions of preserved myocardial thickness, such as the left ventricular (LV) septum. The LV substrate and the tachycardia circuit during ventricular tachycardias of a 60-year-old man with dilated cardiomyopathy were mapped using an ultra-high-density mapping system and then the Lumipoint, analyzing the EGMs of interest, identified the LAVA in the inferoseptal region. This algorithm may be helpful to quickly target the septal substrate avoiding misleading interpretation.

Pseudo-reentry due to automatic annotation of dissociated activity unmasked by the new Lumipoint™ algorithm.

The new Lumipoint™ algorithm based on map analysis with several features is a valuable aid to understanding complex circuits, particularly as it can unmask areas with dissociated activity misleadingly annotated by an automatic mapping system.

Is the mid-diastolic isthmus always the best ablation target for re-entrant atrial tachycardias?

Aims: We evaluated the ability of an ultrahigh mapping system to identify the most convenient Rhythmia ablation target (RAT) in intra-atrial re-entrant tachycardias (IART) in terms of the narrowest area to transect to interrupt the re-entry.

Methods: A total of 24 consecutive patients were enrolled with a total of 26 IARTs. The Rhythmia mapping system was used to identify the RAT in all IARTs.

Mapping and Ablation of Retrograde Conduction During a Nearly Incessant Pacemaker-mediated Tachycardia in a Patient with Third-degree Atrioventricular Block.

Patients with third-degree atrioventricular block implanted with a dual-chamber pacemaker in DDD mode can develop pacemaker-mediated tachycardias if retrograde ventriculoatrial (VA) conduction is present. Programming a long post-VA refractory period to avoid tachycardia initiation can be contraindicated if these patients have a good atrial response from exercise testing and require a high maximum tracking rate to allow for a proper response to sensed atrial rhythms. We report a case of a patient in whom mapping and ablation of retrograde conduction during the pacemaker-mediated rhythm was the only solution to allow both the programming of a high tracking rate and the elimination of tachycardia induction.

High-density mapping to guide ablation of a right bundle branch morphology premature ventricular contraction from the right outflow tract.

The Rhythmia ultrahigh-density mapping system with a specific algorithm seems to be helpful in identifying the target area to successfully treat multiple morphologies by catheter ablation in the right ventricular outflow tract RVOT. Interestingly, the acquisition process seemed to be extremely faster than a standard manual point-by-point premature ventricular contraction (PVC) mapping.