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The effective diagnosis and management of procedural complications remains an important challenge for electrophysiology operators. Intracardiac echocardiography provides a real-time imaging modality with spectral and color Doppler capabilities that integrates directly with electroanatomic mapping systems. It provides detailed characterization of anatomic variants, which allows the operator to optimize the ablation strategy to the individual thereby avoiding the inherent risk of excessive or ineffective lesions. Complications, such as intracardiac thrombus or pericardial effusion, can be detected and managed before the onset of clinical symptoms. Intracardiac echocardiography facilitates the diagnosis and management of intraoperative hypotension.

Interest in endomyocardial biopsy (EMB) has progressively grown during the past decade. Still, its use remains limited to highly specialized centers, mostly because it is considered an invasive procedure with poor diagnostic yield and inherent complications. Indeed, the diagnostic performance of EMB is strictly linked to the sample of myocardium we can obtain. If we can precisely localize areas of diseased myocardium, sampling error or inadequate withdrawals are minimized. In this state-of-the-art review, we provide guidance on how to technically and practically perform EMB guided by electroanatomic voltage mapping and intracardiac echocardiography, and review the evidence supporting this combined approach.

Percutaneous epicardial access continues to have a growing role within cardiac electrophysiology. The classic approach has typically been with a Tuohy needle via a subxiphoid approach guided by fluoroscopic landmarks and tactile feedback. Recent developments have highlighted the role of the micropuncture needle, electroanatomic mapping, and real-time pressure sensors to reduce complications. Further, different access sites, such as the right atrial appendage, have been described and may offer a novel approach to percutaneous epicardial access. In addition, future directions of percutaneous access may involve direct visualization, near-field impedance monitoring, and real-time virtual imaging.

In stable ventricular tachycardia (VT), activation mapping and entrainment mapping are the most important strategies to describe the reentrant circuit and its critical components. In many patients, however, VT is noninducible or hemodynamically unstable and unmappable. Several technological advances have broadened ablation options in unmappable VTs. Preprocedural imaging and intraprocedural imaging play an important role in location and extent of the substrate. Electroanatomic mapping with several technological improvements allows more precise electrical assessment of the substrate. A combination of imaging and electroanatomic mapping allows substantial modification of arrhythmogenic substrate in sinus rhythm or during device pacing without hemodynamic compromise.

Ventricular tachycardia is typically hemodynamically unstable. Strategies to target the arrhythmogenic substrate during sinus rhythm are essential for therapeutic ablation. Electroanatomic mapping is the cornerstone of substrate-based strategies; ablation can be directed within a delineated scar region defined by low voltage. Bipolar voltage mapping has inherent limitations. Specific electrogram characteristics may improve the specificity of localizing the most arrhythmogenic regions within the substrate. Deceleration zones during sinus rhythm are niduses for reentry and can be identified by isochronal late activation mapping, which is a functional analysis of substrate propagation with local annotation to electrogram offset.

Intracardiac echocardiography (ICE) is the most practical method for online imaging during electrophysiological procedures. It allows guiding of complex catheter ablation procedures together with electroanatomical mapping systems, either with minimal or with zero fluoroscopy exposure. Besides safe and reproducible transseptal puncture, ICE helps to assess location and contact of the tip of the ablation catheter relative to specific anatomical structures. Another option is visualization of the arrhythmogenic substrate in patients with ventricular arrhythmias. This article describes the clinical utility of ICE in non-fluoroscopic electrophysiology procedures more in detail.

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.

Life expectancy of patients with rToF has considerably improved due to refined surgical interventions. Monomorphic fast VTs are frequently encountered in adult patients with rToF. The dominant substrate of VT is anatomical isthmuses bordered by surgical incisions, patch material and valve annuli. Substrate based ablation strategies aim to transect all slow conducting anatomical isthmuses (SCAI) as identified by electroanatomical mapping. Procedural success is defined as non-inducibility of VT and confirmed conduction block over the SCAI resulting in long-term VT free survival in most patients. The identification of SCAIs in rToF may have important implications for risk stratification and preventive treatment.

Endocardial and epicardial electroanatomical mapping and ablation is a safe and effective therapy in the treatment of right ventricle arrhythmias occurring in the setting of arrhythmogenic right ventricular cardiomyopathy (ARVD). Careful mapping and ablation plans must be tailored for each patient based on comorbidities and ventricular tachycardia morphologies. This review focuses on the catheter ablation for ventricular arrhythmias in patients with ARVD.

To characterize cardiac activity and arrhythmias, electrophysiologists can record the electrical activity of the heart in relation to its anatomy through a process called cardiac mapping (electroanatomic mapping, EAM). A solid understanding of the basic cardiac biopotentials, called electrograms, is imperative to construct and interpret the cardiac EAM correctly. There are several mapping approaches available to the electrophysiologist, each optimized for specific arrhythmia mechanisms. This article provides an overview of the fundamentals of EAM.

Mapping and ablation in the pericardial space has been shown to be beneficial for the treatment of different supraventricular and ventricular arrhythmias. The percutaneous subxiphoid approach is the most frequently used approach to access the pericardial space. Mapping and ablation in this space may be challenging because it is an open space without obstacles where catheters can move freely, making some locations difficult to reach. Remote magnetic navigation is a modern way to overcome many of the limitations the electrophysiologist encounters during mapping and ablation of arrhythmias in the pericardial space. This article recounts the authors' experiences and reviews the limited data on this topic.

A case of atrial arrhythmia after lung transplant is presented. The key features of this case are relevant to most atypical flutters. A combination of entrainment and electroanatomic mapping can help to efficiently identify the culprit area. The target is typically a long mid-diastolic fractionated potential shown to be integral to the circuit by entrainment mapping. A micro-reentrant circuit may appear to be focal by the electroanatomic map, but entrainment techniques can still be used to localize the tachycardia.

Fluoroscopy-based cardiac mapping techniques can be used for mapping atrial tachycardia after atrial fibrillation ablation. The local atrial activation time can be determined with intracardiac bipolar electrograms alone, providing a sharp local activation time in combination with unipolar electrograms, the morphology of which provides important information regarding wave genesis and propagation. Using conventional activation mapping and entrainment mapping techniques, most atrial tachycardia can be mapped accurately.

Compared to patients with prior myocardial infarction, mapping and ablation of ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) patients represents a unique challenge, often with non-endocardial myocardial substrate, multiple VT morphologies, and higher incidence of arrhythmia recurrence post-ablation. Multi-modality imaging and detailed electroanatomic mapping demonstrated two predominant regional scar distributions: basal inferolateral and basal anteroseptal locations. Among the latter group, patients with predominantly septal scar pose a particularly difficult subset. Careful and systemic mapping is required to define the VT substrate. Aggressive ablations are often required from both sides of the septum to achieve arrhythmia control.

Radiofrequency ablation has become a mainstay in the therapy for atrial fibrillation (AF). Although there are many different techniques for achieving adequate results, the cornerstone of AF remains pulmonary vein isolation. Three-dimensional (3D) electroanatomical mapping systems play an important role in the reduction of fluoroscopy and the identification of electrical and anatomic landmarks and are used commonly in AF ablation procedures. In this article, the authors discuss the advantages and limitations of 3D mapping systems and try to answer the question: Are they needed for successful AF ablation ?

Monomorphic ventricular tachycardia (VT) is a natural consequence of the unique fibrotic process seen in arrhythmogenic cardiomyopathy. The fibrosis is confluent and is centered around the epicardium of the right ventricle in most cases, progressing inwards towards the endocardium. This has important implications for the mechanism, surface morphology, size and location of the reentrant VT circuits seen in this disease. This article examines the electrophysiologic substrate underlying monomorphic VT in arrhythmogenic cardiomyopathy. It also explores the current role and technique of endocardial and epicardial catheter ablation of VT in this condition.