Mapping the diastole: ultra-high-density substrate mapping in ventricular tachycardia

Outcomes of ventricular tachycardia ablation in patients with ischemic and non-ischemic cardiomyopathy: A propensity-score matched analysis

INTRODUCTION AND OBJECTIVES

Catheter ablation (CA) is effective in the treatment of ventricular tachycardia (VT). Although some observational data suggest patients with non-ischemic cardiomyopathy (NICM) have less favorable outcomes when compared to those with an ischemic etiology (ICM), direct comparisons are rarely reported. We aimed to compare the outcomes of VT ablation in a propensity-score matched population of ICM or NICM patients.

METHODS

Single-center retrospective study of consecutive patients undergoing VT ablation from 2012 to 2023. A propensity score (PS) was used to match ICM and NICM patients in a 1:1 fashion according to age, sex, left ventricular ejection fraction (LVEF), NYHA class, electrical storm (ES) at presentation, and previous endocardial ablation. The outcomes of interest were VT-free survival and all-cause mortality.

RESULTS

The PS yielded two groups of 71 patients each (mean age 63±10 years, 92% male, mean LVEF 35±10%, 36% with ES at presentation, and 23% with previous ablation), well matched for baseline characteristics. During a median follow-up of 2.3 (interquartile range IQR 1.3-3.8) years, patients with NICM had a significantly lower VT-free survival (53.5% vs. 69.0%, log-rank p=0.037), although there were no differences regarding all-cause mortality (22.5% vs. 16.9%, log-rank p=0.245). Multivariate analysis identified NICM (HR 2.34 [95% CI 1.32-4.14], p=0.004), NYHA class III/IV (HR 2.11 [95% CI 1.11-4.04], p=0.024), and chronic kidney disease (HR 2.23 [95% CI 1.25-3.96], p=0.006), as independent predictors of VT recurrence.

CONCLUSION

Non-ischemic cardiomyopathy patients were at increased risk of VT recurrence after ablation, although long-term mortality did not differ.

The advantage of mini electrode-equipped catheter for the radiofrequency ablation of paroxysmal supraventricular tachycardia

INTRODUCTION

Novel ablation catheters equipped with mini-electrodes (ME) offer high resolution mapping for target tissue. This study aimed to evaluate the mapping performance and efficacy of ME catheters in radiofrequency ablation (RFA) of paroxysmal supraventricular tachycardias (PSVTs).

METHODS

We prospectively enrolled 136 patients undergoing RFA of PSVT including 76 patients with atrioventricular nodal reentrant tachycardia (AVNRT) and 60 patients with atrioventricular reentrant tachycardia (AVRT) or Wolff-Parkinson-White (WPW) syndrome. Patients were randomized to the ME group (ablation using ME catheters) or the control group (ablation using conventional catheters). The number of ablation attempt and cumulative ablation time to ablation endpoints, which was defined as an emergence of junctional rhythm in AVNRT or accessory pathway (AP) block in AVRT/WPW syndromes were compared.

RESULTS

During ablation procedures, discrete slow pathway or AP electrograms were found in 27 (39.7%) patients in the ME group and 13 (19.1%) patients in the control group. The primary study outcomes were significantly lower in the ME group (ablation attempt number: 2.0 [1-4] vs. 3.0 [2-7] in the ME and control group, p=0.032; ablation time: 23.5 [5.0-111.5] vs. 64.5 [16.0-185.0] seconds, p=0.013). According to the PSVT diagnosis, ablation time to junctional rhythm was significantly shorter in the ME group in AVNRT. In AVRT/WPW syndrome, both ablation attempt number and ablation time to AP block were non-significantly lower in the ME group.

CONCLUSION

The novel ME catheter was advantageous for identifying pathway potentials and reducing initial ablation attempt number and ablation time to reach acute ablation endpoint for PSVTs. (ClinicalTrials.gov number, NCT04215640) This article is protected by copyright. All rights reserved.

Electroanatomic voltage mapping for tissue characterization beyond arrhythmia definition: A systematic review

Three-dimensional (3D) reconstruction by means of electroanatomic mapping (EAM) systems, allows for the understanding of the mechanism of focal or re-entrant arrhythmic circuits, which can be identified by means of dynamic (activation and propagation) and static (voltage) color-coded maps. However, besides this conventional use, EAM may offer helpful anatomical and functional information for tissue characterisation in several clinical settings. Today, data regarding electromechanical myocardial viability, scar detection in ischaemic and nonischaemic cardiomyopathy and arrhythmogenic right ventricle dysplasia (ARVC/D) definition are mostly consolidated, while emerging results are becoming available in contexts such as Brugada syndrome and cardiac resynchronisation therapy (CRT) implant procedures. As part of an invasive procedure, EAM has not yet been widely adopted as a stand-alone tool in the diagnostic path. We aim to review the data in the current literature regarding the use of 3D EAM systems beyond the definition of arrhythmia.

Electroanatomic voltage mapping and characterisation imaging for "right ventricle arrhythmic syndromes" beyond the arrhythmia definition: a comprehensive review

Three-dimensional (3D) reconstruction by means of electroanatomic mapping (EAM) systems, allows for the understanding of the mechanism of focal or re-entrant arrhythmic circuits along with pacing techniques. However, besides this conventional use, EAM may offer helpful anatomical and functional information. Data regarding electromechanical scar detection in ischaemic (and nonischaemic) cardiomyopathy are mostly consolidated, while emerging results are becoming available in contexts such as arrhythmogenic right ventricular dysplasia (ARVC/D) definition and Brugada syndrome. As part of an invasive procedure, EAM has not yet been widely adopted as a stand-alone tool in the diagnostic path. We aim to review the current literature regarding the use of 3D EAM systems for right ventricle (RV) functional characterisation beyond the definition of arrhythmia.