To assess the cost-utility of ablation guided by three-dimensional electroanatomical mapping (3DEAM) with antiarrhythmic drug (AAD) therapy in the management of patients with idiopathic ventricular arrhythmias (IVA) at a highly specialized cardiovascular center in Peru. A cost-utility economic evaluation was conducted in a public institution involving patients diagnosed with IVAs between 2017 and 2022. The analysis included projections adjusted according to life expectancy. Cost analysis was performed from the payer’s perspective (public health insurance) using the macro-cost estimation methodology and applying a 9.6

Anatomy:We aim to review the anatomy of the moderator band (MB) and the trabeculated right ventricle (RV). Pathology:We thoroughly describe the morphological variations of the MB and its spatial relationship with the right ventricular anterior papillary muscle, its muscular trabeculations, and the free wall. Imaging correlation:We provide echocardiography, computed tomography, and magnetic resonance imaging to better understand histologic specimens of the MB, the trabeculated RV, and the right ventricular papillary muscles. Treatment:We provide examples of intracardiac echocardiography and transesophageal echocardiogram to guide safe and effective structural interventions in the RV, and mapping and ablation of ventricular arrhythmias arising from the MB.

Clinical applications relevant to the sinoatrial node anatomy for interventional electrophysiology procedures are reviewed. Inappropriate sinus tachycardia, atrial tachycardia, and superior vena cava triggers for atrial fibrillation. Three-dimensional electroanatomic mapping, intracardiac echocardiography. Ablation guided by activation mapping and intracardiac electrograms. Understanding the anatomy of the sinoatrial node and the perinodal region provides key anatomic concepts to safely and effectively guide ablation procedures.

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.

Conduction abnormalities requiring permanent pacemaker (PPM) are a frequent complication following TAVR. Few studies have evaluated chronic pacemaker dependency after TAVR. To evaluate post-TAVR pacemaker dependency and impact on mortality at one year. 626 patients with severe aortic stenosis who underwent TAVR between 01/01/2012 and 12/31/2019 were identified. Those with pre-TAVR pacemaker were excluded. Patients underwent post TAVR PPM if found to have high grade AV block,> 5seconds pause or symptomatic bradycardia < 50 bpm. Patients who underwent TAVR without PPM implant represented the control arm. PPM dependency was defined as > 50% pacing during 1 and 30 days post implantation. All-cause mortality was reported at one year. Of 357 patients, 16% required PPM with no difference in either balloon expandable or self-expandable valve types (14.6% vs 17.6%; P=0.471). The mean age was 80 + 8.2 years, and 52.7% were male. The median time to PPM implantation was 2 days. The main indications were complete AV block (67%) and symptomatic bradycardia (8.8%). 56.1% received a dual chamber, 24.6% a single chamber and 8.8% received a biventricular PPM. At day 1 and 30 days following implant 73.7% and 78.9% of patient fulfilled criteria for PPM dependency. There were no difference in mortality between the cohorts at one year (Fig. 1). 78% of patients requiring PPM post TAVR were pace dependent at 30 days. PPM implantation did not have an impact on mortality at 1 year. Indications for acute pacing predicted PPM dependency at 30 days and support the selection criteria used for PPM implantation in this cohort.

We aimed to study the characteristics of the membranous septum (MS) and its relationship with the aortic valve (AoV) and aortic annulus (AA) in patients who required PPM post-TAVR. We performed a retrospective case–control study of 144 patients undergoing TAVR from 2016 to 2018. Thirty-four patients, requiring PPM implantation, were compared with 34 matched controls who did not require pacing. The total MS length, supra-annular MS (SA-MS) length, infra-annular MS (IA-MS) length, angle between the plane of the AA and MS (AA-MS), and degree of AoV calcifications (AVC) were obtained from preoperative CT. AoV prosthesis implantation depth was obtained from intra-operative fluoroscopy. There were no significant differences in valve type (self-expandable: 23 cases vs 25 controls, and balloon-expandable: 11 vs 9, p = 0.79), degree of AVC (0.65 cm3 vs 0.82 cm3, p = 0.62), or implantation depth (7.76 mm vs 7.28 mm, p = 0.83). Compared to controls, there was no difference in total MS length (6.68 mm vs 6.06 mm, p = 0.97), but the IA-MS was significantly shorter (3.64 mm vs 4.56 mm, p = 0.02) and the SA-MS was significantly longer (2.73 mm vs 1.67 mm, p = 0.02) in patients requiring PPM. Patients requiring PPM also had a larger AA-MS angle (103.5° vs 96.7°, p = 0.01). The position of the MS with respect to the AA and MS distance below the annular plane were more closely associated with post-TAVR conduction abnormalities requiring PPM than the absolute length of the MS. Patients undergoing TAVR with such anatomy have a higher risk of requiring PPM and should be monitored for developing these complications.

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.

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.

Background: Functional/molecular imaging characteristics of ischemic ventricular tachycardia (VT) substrate are incompletely understood. Objective: Compare regional 18F-FDG - PET tracer uptake with detailed electroanatomic maps (EAM) in a more extensive series of post-infarction VT patients to define metabolic properties of the VT substrate/successful ablation sites. \n\nMethods: 3D metabolic left ventricular (LV) reconstructions were created from perfusion-normalized 18F-FDG images in consecutive patients undergoing VT ablation. Metabolic defects were defined as severe (\u003c50% uptake) or moderate (50-70% uptake) referenced to the maximal 17-segmental uptake. Color-coded PET scars reconstructions were co-registered with corresponding high-resolution 3D EAM. \n\nResults: All 56 patients had ischemic cardiomyopathy (EF=29±12%). Severe PET defect ( 70% (n = 7,782, 3.2±1.3mV, p 70%). Metabolic channels (n = 26) existed in 45% (n = 25) of patients with average length/width of 17.6±12.5mm/10.3±4.2mm. Metabolic channels were oriented apex/base (86%) predominantly, harboring VT channel/exit sites in 31%. Metabolic Rapid Transition Areas (RTA: \u003e50% change of 18F-FDG tracer uptake/15mm) were detected in 59% (n = 33) co-localizing to VT channels/exit sites (15%) or its proximity (85%, 12.8±8.5mm). Metabolism-voltage mismatches (MVM) with PET 1.5mV) were seen in 21% (n = 12) harboring VT channel/exit sites in 41% of patients. \n\nConclusion: Abnormal 18F-FDG uptake categories can be detected using incremental 3D step-up reconstructions. They predicted decreasing bipolar voltages and VT channel/exit sites in ~90%. Additionally, functional imaging allowed detecting novel molecular tissue characteristics within the ischemic VT substrate such as metabolic channels, RTA, and MVM demonstrating intra-substrate heterogeneity and providing possible targets for imaging-guided ablation.

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.)

Introduction: Prior to ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO. Methods: Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24-hour ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation. Results: High VE variability (coefficient of variation ≥ 0.7) and the presence of any hour with < 50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%). Conclusion: VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favourably to existing ECG algorithms.