Intracardiac echocardiography guided anatomical ablation of the arcuate ridge for drug refractory inappropriate sinus tachycardia.

INTRODUCTION: Inappropriate sinus tachycardia (IST) is a common condition with frequently not tolerated beta-blockers or ivabradine and a high rate of complication in ablation strategy; we describe an alternative anatomical approach of sinus node (SN) modulation. METHODS: This retrospective study describes a case series of 6 patients from two centers diagnosed with symptomatic IST undergoing SN ablation. RESULTS: The mean age was 40.6 ± 13.9 years; five of the six patients were female, 100% of patients reported heart palpitations, and 66% reported dizziness, the average heart rate (HR) on a 24-h Holter was 93.2 ± 7.9 bpm. HR during the first stage of a stress test using a standard Bruce protocol was 150 ± 70 bpm, The average HR on 24-h Holter postablation was 75 ± 5.6 bpm, the sinus rate HR during stage 1 of a Bruce protocol exercise stress test was 120 ± 10 bpm. CONCLUSION: This is the first case series reporting the acute and long-term results of a novel anatomical approach for SN modulation to treat IST targeting the arcuate ridge (AR) under intracardiac echography (ICE) guidance. The novel anatomic ICE-guided catheter ablation approach aimed to identify the earliest activation at the AR with an extension of RF lesions toward its septal region seems effective and safe to modulate the SN in symptomatic patients with IST refractory to medical treatment.

Preventing Complications During Mapping and Ablation of Left Ventricular Summit Arrhythmias.

The left ventricular summit is a site of origin for idiopathic ventricular arrhythmias. With advancements in mapping and ablation techniques, sites previously considered inaccessible can now be approached. Anatomical knowledge of the 3-dimensional landmarks of this space is important, as critical structures reside within its boundaries and are potentially liable to collateral injury during ablation. This article reviews reported complications from ablation of ventricular arrhythmias arising from the left ventricular summit and its vicinity and discusses the pros and cons of different ablation technique and the role of an individualized anatomical approach to reduce procedural related complications and improve outcomes.

Dominant vector changes during early wavebreak/spiral wave (Wiggers stage 1) in ventricular fibrillation: insights from the analysis of 100 electrophysiology studies.

PURPOSE: To describe electrocardiographic vector patterns during early VF transition (Wiggers stage 1). METHODS: In 100 electrophysiology studies with VF induction, the first 3 beats of VF were analyzed in lead I for left/right axis (LA/RA), V1 for left/right bundle (LB/RB), and aVF for superior/inferior axis (SA/IA). Correlation with demographic/clinical factors was performed using regression analyses and mixed effect modeling. RESULTS: VF initiated more likely with LA than RA (P < 0.001) and LB than RB (P = 0.04) suggesting original wavebreak in the right ventricle. The 3-dimensional morphology changed in 69% of VF during the first 3 beats, with predominant increase in RB, suggesting a transition of QRS-originating vector to septum/left ventricle. Conservation of morphology (31%) was favored by initial RB (P = 0.002) and LA morphology (P = 0.01). Initiation of VF with LA vs RA was more likely in African-Americans (P = 0.016) and increasing age (P = 0.032). Ischemic cardiomyopathy favored VF initiation with RB 6.7-fold (P = 0.025), possibly linking LV myocardial scar to initial VF wavebreak location. Male gender and ischemic cardiomyopathy prolonged time-to-loss of predominant vector by 119% (P = 0.002) and 71% (P = 0.017), respectively, suggesting more preserved anatomic/functional reentry. CONCLUSION: The predominant QRS vectors during early Wiggers stage 1 VF are not random and suggest an initial wavebreak more commonly in the right ventricle, followed by a transitional shift to the septum/left ventricle. Ethnicity, male gender, age, and co-morbidities result in directional preservation of initiating VF vectors possibly due to myocardial mass/fibrosis. Findings may allow new treatment/ablation approaches.

A Novel Use of Noninvasive Registered Electrocardiographic Imaging Map for Localization of VT and PVC.

A 33-year-old woman presented with sustained monomorphic ventricular tachycardia (VT). The 12-lead electrocardiogram, 3-dimensional (3D) picture of chest electrodes, and cardiac magnetic resonance were used to create a noninvasive 3D electrocardiographic imaging map to identify the most likely site of VT origin. This map was integrated with a 3D mapping system to aid in VT ablation. (Level of Difficulty: Advanced.).

Image Integration Using Intracardiac Echography and Three-dimensional Reconstruction for Mapping and Ablation of Atrial and Ventricular Arrhythmias.

This article reviews the basis for image integration of intracardiac echocardiography (ICE) with three-dimensional electroanatomic mapping systems and preprocedural cardiac imaging modalities to enhance anatomic understanding and improve guidance for atrial and ventricular ablation procedures. It discusses the technical aspects of ICE-based integration and the clinical evidence for its use. In addition, it presents the current technical limitations and future directions for this technology. This article also includes figures and videos of clinical representative arrhythmia cases where the use of ICE is key to a safe and successful outcome.

Perioperative Imaging to Guide Epicardial Mapping and Ablation.

Accessing the epicardial space without a sternotomy or a surgical pericardial window to treat ventricular arrhythmias in Chagas disease became a medical necessity in South America. Since the introduction of the dry percutaneous epicardial access approach, epicardial access has been standard procedure for management of ventricular arrhythmias in ischemic and nonischemic cardiomyopathies and atrioventricular accessory pathways after failed conventional endocardial ablation. Understanding the epicardial space and neighboring structures has become an important subject of teachings in electrophysiology. The evolution of complex ablation procedures to treat atrial and ventricular arrhythmias and device interventions to prevent cardioembolic stroke requires thorough understanding of pericardial anatomy.