A Randomized Trial of Electrographic Flow-Guided Redo Ablation for Nonparoxysmal Atrial Fibrillation (FLOW-AF).

BACKGROUND: Electrographic flow (EGF) mapping enables full spatiotemporal reconstruction of organized wavefront propagation to identify extrapulmonary vein sources of atrial fibrillation (AF). OBJECTIVES: FLOW-AF (A Randomized Controlled Study to Evaluate the Reliability of the Ablacon Electrographic FLOW [EGF] Algorithm Technology [Ablamap Software] to Identify AF Sources and Guide Ablation Therapy in Patients With Persistent Atrial Fibrillation) was multicenter, randomized controlled study of EGF mapping to: 1) stratify a nonparoxysmal AF population undergoing redo ablation; 2) guide ablation of these extrapulmonary vein AF sources; and 3) improve AF recurrence outcomes. METHODS: FLOW-AF enrolled persistent atrial fibrillation (PerAF)/long-standing PerAF patients undergoing redo ablation at 4 centers. One-minute EGF maps were recorded from standardized biatrial basket positions. Patients with source activity ≥26.5% were randomized 1:1 to PVI + EGF-guided ablation vs PVI only; patients without sources ≥26.5% threshold were not randomized. Follow-up and electrocardiographic monitoring occurred at 3, 6, and 12 months. RESULTS: We enrolled 85 patients (age 65.6 ± 9.3 years, 37% female, 24% long-standing PerAF). Thirty-four (40%) patients had no sources greater than threshold; at least 1 source greater than threshold was present in 46 (60%) (EGF-guided ablation, n = 22; control group, n = 26). Patients with sources were older (68.2 vs 62.6 years; P = 0.005) with higher CHA2DS2-VASc scores (2.8 vs 1.9; P = 0.001). The freedom from safety events was 97.2%, and 95% of EGF-identified sources were successfully ablated. In randomized patients, AF-free survival at 12 months was 68% for EGF-guided ablation vs 17% for the control group (P = 0.042); freedom from AF/atrial tachycardia/atrial flutter at 12 months was 51% vs 14% (P = 0.103), respectively. CONCLUSIONS: In nonparoxysmal AF patients undergoing redo ablation, EGF mapping identified AF sources in 60% of patients, and could be successfully ablated in 95%. Compared with PVI alone, PVI + source ablation improved AF-free survival by 51% on an absolute basis. (FLOW-AF: A Study to Evaluate the Ablacon Electrographic FLOW EGF Technology [A Randomized Controlled Study to Evaluate the Reliability of the Ablacon Electrographic FLOW (EGF) Algorithm Technology (Ablamap Software) to Identify AF Sources and Guide Ablation Therapy in Patients With Persistent Atrial Fibrillation]; NCT04473963).

Key influences of VDD (DX) ICD selection: Results from a prospective, national survey.

BACKGROUND: To preserve the benefit of atrial sensing without the implantation of an additional lead, a single-lead ICD system with a floating atrial dipole (DX ICD) has been developed. The purpose of this nationwide survey was to provide an overview of the current key influences of device selection focusing on DX ICD and to test the applicability of a previously published decision-making flowchart of ICD-type selection. METHODS: An online questionnaire was sent to all implanting centers in Hungary. Eleven centers reported data from 361 DX ICD and 10 CRT-DX systems implantations between February 2021 and May 2023. RESULTS: The most important influencing clinical factors indicated by the participating doctors were elevated risk of atrial fibrillation (AF)/stroke (56%), risk of sinus/supraventricular tachycardias (SVT) (42%), and a potential need for CRT upgrade in the future (36%). The DX ICD was considered in the majority of cases instead of the VVI system (87%), and only in a small proportion instead of a DDD ICD (13%). 60% of the patients with DX ICDs were also included into remote monitoring-based follow-up. In 83% of the cases, good (>2 mV) or excellent (>5) atrial signal amplitude was recorded within 6 weeks after the implantation. CONCLUSION: In the current national survey, the most important influencing factors indicated by the implanters for selecting a DX ICD were the elevated risk of stroke or sinus/SVT and a potential need for CRT upgrade in the future. These findings support the use of a previously published decision-making flowchart.

Risk of Cardiac Implantable Electronic Device Infection after Early versus Delayed Lead Repositioning.

(1) Background: Early reintervention increases the risk of infection of cardiac implantable electronic devices (CIEDs). Some operators therefore delay lead repositioning in the case of dislocation by weeks; however, there is no evidence to support this practice. The aim of our study was to evaluate the impact of the timing of reoperation on infection risk. (2) Methods: The data from consecutive patients undergoing lead repositioning in two European referral centers were retrospectively analyzed. The odds ratio (OR) of CIED infection in the first year was compared among patients undergoing early (≤1 week) vs. delayed (>1 week to 1 year) reoperation. (3) Results: Out of 249 patients requiring CIED reintervention, 85 patients (34%) underwent an early (median 2 days) and 164 (66%) underwent a delayed lead revision (median 53 days). A total of nine (3.6%) wound/device infections were identified. The risk of infection was numerically lower in the early (1.2%) vs. delayed (4.9%) intervention group yielding no statistically significant difference, even after adjustment for typical risk factors for CIED infection (adjusted OR = 0.264, 95% CI 0.032-2.179, p = 0.216). System explantation/extraction was necessary in seven cases, all being revised in the delayed group. (4) Conclusions: In this bicentric, international study, delayed lead repositioning did not reduce the risk of CIED infection.

Device infection in patients undergoing pacemaker or defibrillator surgery: risk stratification using the PADIT score.

BACKGROUND: The use of an antibacterial envelope is cost-effective for patients at high risk of developing cardiac implantable electronic device (CIED) infection. The identification of these high-risk patients may be facilitated using a clinical risk score. The aim of the current study is to evaluate the PADIT score for identifying high-risk patients in patients undergoing a CIED procedure in a tertiary academic center. METHODS: This was a retrospective single-center study of consecutive patients undergoing a CIED procedure between January 2016 and November 2021. Patients who received an antibacterial envelope were excluded from this study. The primary endpoint was hospitalization for a CIED infection in the first year after the procedure. RESULTS: A total of 2333 CIED procedures were performed in the study period (mean age 61.6 ± 16.3 years, male sex 64.5%, previous CIED infection 1.7%, immunocompromised 5.4%). The median PADIT score was 4 (interquartile range, 2-6). CIED infection occurred in 10 patients (0.43%). The PADIT score had good discrimination in predicting major CIED infection (C-statistic 0.70; 95% confidence interval [CI] 0.54 to 0.86, P = 0.03). Using an optimal PADIT score cut-off value of 7, the risk of CIED infection was higher in the patients with a PADIT score of ≥ 7 in comparison to those with a lower PADIT score (1.23% vs. 0.26%, P = 0.02; odds ratio 4.8, 95% CI 1.4 to 16.6, P = 0.01). CONCLUSIONS: The PADIT score is a clinically useful score for identifying patients at high risk of developing CIED infection. The use of an antibacterial envelope in these high-risk patients may be cost-effective.

Indirect Insulin Resistance Indices and Their Cut-Off Values for the Prediction of Post-Transplantation Diabetes Mellitus in Kidney Transplant Recipients.

BACKGROUND: Insulin resistance plays an important role in the development of post-transplantation diabetes mellitus (PTDM) in kidney transplant recipients (KTRs). Current methods for the direct determination of insulin resistance are complicated and invasive. Therefore, this study aimed to investigate the relevance of indirect insulin resistance indices in relation to the development of PTDM in KTRs. METHODS: We included 472 stable outpatient KTRs without diabetes at baseline from a prospective cohort study. Four indirect insulin resistance indices, namely homeostasis model assessment-insulin resistance (HOMA-IR), visceral adiposity index (VAI), lipid accumulation product (LAP), and triglycerides-glucose (TyG) index, were assessed. We analyzed each measure using the receiver operating characteristic (ROC) curve for PTDM development. The optimal cut-off value for each parameter was determined using the Youden index. RESULTS: After a median of 9.6 years (interquartile range (IQR) 6.6-10.2) of follow-up, 68 (14%) KTRs developed PTDM. In Cox regression analyses, all indirect insulin resistance indices associated with incident PTDM were independent of potential confounders. ROC curve was 0.764 (95% CI, 0.703-0.826) for HOMA-IR, 0.685 (95% CI, 0.615-0.757) for VAI, 0.743 (95% CI, 0.678-0.808) for LAP, and 0.698 (95% CI, 0.629-0.766) for TyG index, with respective optimal cut-off values of 2.47, 4.01, 87.0, and 4.94. CONCLUSIONS: Indirect insulin resistance indices can be used to predict incident PTDM in KTRs. In addition to HOMA-IR, insulin-free surrogates of insulin resistance might serve as useful methods to identify KTRs at risk of PTDM, thus obviating the necessity to measure insulin.

Dynamic Perfusion Computed Tomography for the Assessment of Concomitant Coronary Artery Disease in Patients with a History of Percutaneous Transluminal Angioplasty for Chronic Limb-Threatening Ischemia-A Pilot Study.

BACKGROUND: Chronic limb-threatening ischemia (CLTI) is associated with high rates of long-term cardiovascular mortality. Exercise stress testing to detect obstructive coronary artery disease (CAD) can be difficult in this subset of patients due to inability to undergo exercise testing, presence of balanced ischemia and severe coronary artery calcification (CAC). AIM: To test the feasibility of regadenoson stress dynamic perfusion computed tomography (DPCT) in CLTI patients. METHODS: Between 2018 and 2023, coronary computed tomography angiography (CTA) and, in the case of a calcium score higher than 400, DPCT, were performed in 25 CLTI patients with a history of endovascular revascularization. RESULTS: Of the 25 patients, 19 had a calcium score higher than 400, requiring DPCT image acquisition. Obstructive CAD could be ruled out in 10 of the 25 patients. Of the 15 CTA/DPCT+ patients, 13 proceeded to coronary angiography (CAG). Revascularization was necessary in all 13 patients. In these 13 patients, vessel-based sensitivity and specificity of coronary CTA/DPCT as compared to invasive evaluation was 75%, respectively. At follow-up (27 ± 21 months) there was no statistically significant difference in all-cause mortality between CTA/DPCT- positive and -negative patients (p = 0.065). CONCLUSIONS: Despite a high prevalence of severe CAC, coronary CTA complemented by DPCT may be a feasible method to detect obstructive and functionally significant CAD in CLTI patients.

Single accessory pathway with multiple insertions? First-in-human 3D visualization using dipole charge density mapping: a case report.

Background: Accessory pathways (APs) with multiple atrial insertions are often unrecognized and associated with initial catheter ablation (CA) failure. Recently, a novel dipole charge density mapping (DCDM) system was developed that allows mapping of complex arrhythmias based on a single beat. We aim to present the first-in-human report of 3D visualization of a single AP with two atrial insertion sites using high-resolution DCDM. Case summary: A 43-year-old man with recurrent symptomatic atrioventricular re-entrant tachycardia and previously failed CA attempts underwent repeated CA using DCDM. Dipole charge density mapping identified two quasi-simultaneous early atrial activation sites at the left lateral and left anterolateral atrial aspects of the mitral annulus, suggesting the presence of a single AP with dual atrial insertion sites. Successful radiofrequency CA was performed at the mid-body of the AP. Discussion: The true prevalence of APs with multiple atrial insertion sites may be higher than currently reported. This is the first-in-human report of 3D visualization of a single AP with two atrial insertion sites using high-resolution DCDM. Dipole charge density mapping allows the accurate localization of APs with multiple insertion sites based on a single beat.

Robotic magnetic navigation-guided catheter ablation establishes highly effective pulmonary vein isolation in patients with paroxysmal atrial fibrillation when compared to conventional ablation techniques.

INTRODUCTION: Pulmonary vein isolation (PVI) is a pivotal part of ablative therapy for atrial fibrillation (AF). Currently, there are multiple techniques available to realize PVI, including: manual-guided cryoballoon (MAN-CB), manual-guided radiofrequency (MAN-RF), and robotic magnetic navigation-guided radiofrequency ablation (RMN-RF). There is a lack of large prospective trials comparing contemporary RMN-RF with the more conventional ablation techniques. This study prospectively compared three catheter ablation techniques as treatment of paroxysmal AF. METHODS: This multicenter, prospective study included patients with paroxysmal AF who underwent their first ablation procedure. Procedural parameters (including procedural efficiency), complication rates, and freedom of AF during 12-month follow-up, were compared between three study groups which were defined by the utilized ablation technique. RESULTS: A total of 221 patients were included in this study. Total procedure time was significantly shorter in MAN-CB (78 ± 21 min) compared to MAN-RF (115 ± 41 min; p < .001) and compared to RMN-RF (129 ± 32 min; p < .001), whereas it was comparable between the two radiofrequency (RF) groups (p = .062). A 3% complication rate was observed, which was comparable between all groups. At 12-month follow-up, AF recurrence was observed in 40 patients (19%) and was significantly lower in the robotic group (MAN-CB 19 [24%], MAN-RF 16 [23%], RMN-RF 5 [8%] AF recurrences, p = .045) (multivariate hazard ratio of RMN-RF on AF recurrence 0.32, 95% confidence interval: 0.12-0.87, p = .026). CONCLUSION: RMN-guided PVI results in high freedom of AF in patients with paroxysmal AF, when compared to cryoablation and manual RF ablation. Cryoablation remains the most time-efficient ablation technique, whereas RMN nowadays has comparable efficiency with manual RF ablation.

Effect of myocardial scar size on the risk of ventricular arrhythmias in patients with chronic total coronary occlusion.

BACKGROUND: The presence of an untreated chronic total coronary occlusion (CTO) is associated with a higher risk of ventricular arrhythmias (VAs). This increased risk may be modulated by the presence of an existing scar. OBJECTIVES: To evaluate whether scar size is associated with VA in patients with an implantable cardioverter-defibrillator (ICD) and a CTO. METHODS: In this retrospective study we included patients with a CTO that received an ICD between 2005 and 2015. Scar size was estimated using the Selvester QRS score on a baseline 12­lead ECG. The primary endpoint was any appropriate ICD therapy. RESULTS: Our study population comprised 148 CTO patients with a median scar size at baseline of 18% (IQR, 9-27%). Patients with a scar size ≥18% more often had a CTO located in the left anterior descending artery and a higher proportion of poor left ventricular function (<35%) and infarct-related CTO compared to patients with a smaller scar size (<18%). During a median follow-up of 35 months (interquartile range [IQR], 8-60 months), 42 patients (28%) received appropriate ICD therapy. The cumulative 5-year event rate was higher in the patients with a large scar in comparison to those with a smaller or no scar (36% versus 19%, P = 0.04). Multivariable Cox regression analysis demonstrated that large scar and diabetes mellitus were independent factors associated with appropriate ICD therapy. CONCLUSION: In ICD recipients with an untreated CTO, a larger scar is an independent factor associated with an increased risk of VA.

Electrographic flow mapping guided catheter ablation offers advantages for patients with persistent atrial fibrillation.

BACKGROUND: Catheter ablation (CA) remains challenging due to suboptimal success rates in persistent atrial fibrillation (AF). Existing mapping technologies cannot reliably distinguish sources in this patient population. Recently, the novel electrographic flow (EGF) mapping system was developed using a modified Horn-Schunk optical flow algorithm to detect and quantify patterns of electrical wavefront propagation in the atria. OBJECTIVES: To test the hypothesis that targeted source ablation based on EGF mapping is superior to empiric AF ablation. METHODS: We included all consecutive patients undergoing EGF guided ablation for persistent AF. All patients underwent pulmonary vein isolation (PVI) and were treated with the same EAM system (CARTO). The outcome of PVI+EGF guided CA was compared with data of PVI-only procedures (PVI-only group) and PVI plus additional empiric adjunctive linear and substrate ablations (PVI+LINES group). 12-months outcome as freedom from AF and atrial tachycardia/flutter (AT/AFL), procedural safety and efficiency characterized by procedure duration, fluoroscopy use, radiofrequency applications and duration, were analyzed. Both intention-to-treat and per protocol analysis were conducted. RESULTS: A total number of 70 patients (39 in PVI+EGF, 16 in PVI-only and 15 patients in PVI+LINES group) were enrolled. Intention-to-treat analysis showed fewer AF recurrences in PVI+EGF as compared with the PVI-only or PVI+LINES groups at 12 months (25.6% vs. 62.5% vs. 53.3%, p = .02). There were no differences in AT/AFL recurrence (17.9% vs. 37.5% vs. 20.0%, p = .37). Procedure times were longer in PVI+EGF group (p < .01), and there were no differences in fluoroscopy use (p = .67). CONCLUSION: Our data suggest that patients treated with EGF-guided CA developed fewer AF recurrences. Although the procedure times are longer, it seems to be safe and offers a more targeted, patient-specific ablation strategy beyond PVI than adjunctive empiric lines and substrate ablation in this complex group of patients.

Fasting Ketone Bodies and Incident Type 2 Diabetes in the General Population.

With rising incidence and prevalence of type 2 diabetes, prevention including identification of prospective biomarkers becomes increasingly relevant. Although ketone bodies recently received a renewed interest as potential biomarkers, data linking these metabolites to diabetes risk are scarce. Therefore, the present prospective study investigated a potential association between fasting ketone bodies and incident type 2 diabetes in the general population. This study from the PREVEND cohort included 3,307 participants from the general population initially free of diabetes or impaired fasting glucose. Baseline fasting ketone body concentrations were measured by nuclear magnetic resonance spectroscopy. One hundred twenty-six participants (3.8%) developed type 2 diabetes during a median (interquartile range) follow-up of 7.3 (6.3-7.6) years. In Kaplan-Meier analysis, sex-stratified ketone body levels strongly positively associated with incident type 2 diabetes, which was confirmed in Cox regression analyses adjusted for several potential confounders. There was no significant interaction by sex. Both 3-ß-hydroxybutyrate and acetoacetate+acetone individually associated with incident type 2 diabetes. In conclusion, fasting plasma ketone body levels are strongly positively associated with incident type 2 diabetes in the general population independent of several other recognized risk factors. These results may have important implications for diabetes prevention including dietary strategies. ARTICLE HIGHLIGHTS: The identification of biomarkers that predict type 2 diabetes is increasingly relevant for personalized medicine strategies. Data regarding ketone bodies and incident type 2 diabetes are scarce. This study shows that ketone bodies, either combined or as individual subspecies, are strongly associated with incident type 2 diabetes in the general population, independent of potential confounders. These results may have important implications for diabetes prevention including dietary strategies.

Electrographic flow-guided ablation in redo patients with persistent atrial fibrillation (FLOW-AF): design and rationale.

Background: Electrographic flow (EGF) mapping enables the dynamic detection of functional or active atrial fibrillation (AF) sources outside the pulmonary veins (PVs), and the presence or absence of these sources offers a novel framework for classifying and treating persistent AF patients based on the underlying pathophysiology of their AF disease. Objective: The primary objective of the FLOW-AF trial is to evaluate the reliability of the EGF algorithm technology (Ablamap software) to identify AF sources and guide ablation therapy in patients with persistent AF. Methods: The FLOW-AF trial (NCT04473963) is a prospective, multicenter, randomized clinical study in which patients with persistent or long-standing persistent AF who have failed prior PV isolation (PVI) undergo EGF mapping after confirmation of intact PVI. In total, 85 patients will be enrolled and stratified based on the presence or absence of EGF-identified sources. Patients with an EGF-identified source above the predetermined activity threshold of ≥26.5% will be randomized in a 1:1 fashion to PVI only vs PVI + ablation of EGF-identified extra-PV sources of AF. Results: The primary safety endpoint is freedom from serious adverse events related to the procedure through 7 days following the randomization procedure; and the primary effectiveness endpoint is the successful elimination of significant sources of excitation with the target parameter the activity of the leading source. Conclusions: The FLOW-AF trial is a randomized study designed to evaluate the ability of the EGF mapping algorithm to identify patients with active extra-PV AF sources.

Long-Term Outcome of ICD Therapy in Patients With Noncompaction Cardiomyopathy Compared With DCM and HCM.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) are frequently used for primary and secondary prevention in patients with cardiomyopathies due to different etiologies. However, long-term outcome studies in patients with noncompaction cardiomyopathy (NCCM) are scarce. OBJECTIVES: This study summarizes the long-term outcome of ICD therapy in patients with NCCM compared with those with dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM). METHODS: Prospective data from our single-center ICD registry were used to analyze the ICD interventions and survival in patients with NCCM (n = 68) compared with patients with DCM (n = 458) and patients with HCM (n = 158) from January 2005 to January 2018. RESULTS: This NCCM population with an ICD for primary prevention comprised 56 (82%) patients with a median age of 43 years and 52% males, compared with 85% in patients with DCM and 79% in patients with HCM (P = 0.20). During a median follow-up of 5 years (IQR: 2.0-6.9 years), appropriate and inappropriate ICD interventions were not significantly different. Nonsustained ventricular tachycardia during Holter monitoring in patients with NCCM was the only significant risk factor for appropriate ICD therapy in patients with NCCM, with a HR of 5.29 (95% CI: 1.12-24.96). The long-term survival was significantly better in the univariable analysis in the NCCM group. However, there was no difference in multivariable Cox regression analyses between the cardiomyopathy groups. CONCLUSIONS: At 5 years of follow-up, the rate of appropriate and inappropriate ICD interventions in NCCM was comparable to that in DCM or HCM. In multivariable analysis, no differences in survival were found between the cardiomyopathy groups.

The performance of dipole charge density mapping integrated with robotic magnetic navigation in the treatment of atrial tachycardias.

BACKGROUND: Catheter ablation (CA) has become a well-established first-line therapy for a broad spectrum of arrhythmias, including atrial tachycardias (ATs). In this study we aimed to assess the performance of the integrated novel high-resolution new generation noncontact mapping system (AcQMap) with robotic magnetic navigation (RMN) system in CA procedures for patients with ATs including comparing patient subgroups based on the utilized mapping modality, arrhythmia mechanism, localization and type of procedure. METHODS: All patients undergoing CA for AT using the AcQMap-RMN system were included. Procedural safety and efficacy were characterized by intra- and post-procedural complications. Acute procedural success and the long-term outcome were assessed in the overall group and in the subgroups. RESULTS: A total number of 70 patients were referred for CA with atrial arrhythmias including 67 AT/AFL (mean age 57.1 ± 14.4 years), and 3 additional patients with inappropriate sinus tachycardia. Thirty-eight patients had de novo AT, 24 had post-PVI AT including 2 patients with perinodal AT, and 5 had post-MAZE AT. Two patients (2.9%) suffered post-procedural complications including 1 patient with groin hematoma and 1 patient with a transient ischemic attack. Acute success was achieved in 63/67 (94.0%) procedures. Thirteen patients (19.4%) had documented recurrence at the end of the 12-months follow-up period. The performance of AcQMap was equally good in focal vs. reentry mechanisms (p = 0.61, acute success), in the left and right atrium (p = 0.21). CONCLUSIONS: AcQMap-RMN integration might improve success rates in CA of ATs with low number of complications.

Treatment of pathophysiologic propagation outside of the pulmonary veins in retreatment of atrial fibrillation patients: RECOVER AF study.

AIMS: RECOVER AF evaluated the performance of whole-chamber non-contact charge-density mapping to guide the ablation of non-pulmonary vein (PV) targets in persistent atrial fibrillation (AF) patients following either a first or second failed procedure. METHODS AND RESULTS: RECOVER AF was a prospective, non-randomized trial that enrolled patients scheduled for a first or second ablation retreatment for recurrent AF. The PVs were assessed and re-isolated if necessary. The AF maps were used to guide the ablation of non-PV targets through elimination of pathologic conduction patterns (PCPs). Primary endpoint was freedom from AF on or off antiarrhythmic drugs (AADs) at 12 months. Patients undergoing retreatment with the AcQMap System (n = 103) were 76% AF-free at 12 months [67% after single procedure (SP)] on or off AADs (80% free from AF on AADs). Patients who had only received a pulmonary vein isolation (PVI) prior to study treatment of non-PV targets with the AcQMap System were 91% AF-free at 12 months (83% SP). No major adverse events were reported. CONCLUSION: Non-contact mapping can be used to target and guide the ablation of PCPs beyond the PVs in persistent AF patients returning for a first or second retreatment with 76% freedom from AF at 12 months. The AF freedom was particularly high, 91% (43/47), for patients enrolled having only a prior de novo PVI, and freedom from all atrial arrhythmias for this cohort was 74% (35/47). These early results are encouraging and suggest that guiding individualized targeted ablation of PCPs may therefore be advantageous to target at the earliest opportunity in patients with persistent AF.

Right ventricular electromechanical dyssynchrony in adults with repaired Tetralogy of Fallot.

Background and purpose: Electromechanical dyssynchrony, manifested by right bundle branch block and regional wall mechanical dysfunction, contributes to inefficient RV function in repaired Tetralogy of Fallot (ToF). This study aims to evaluate the synchronicity of multiple RV walls using two-dimensional multi-plane echocardiography (2D-MPE) in order to augment current understanding of the mechanisms behind RV dyssynchrony. Methods: Sixty-nine adult ToF patients [aged 33 (23-45) years; 61% male] and twenty-five matched healthy controls underwent deformational analysis of the RV lateral, anterior, inferior and septal walls following 2D-MPE acquisitions. RV synchronicity was assessed by the intra-RV deformation delay between each basal RV wall and mid-septal segment in addition to mechanical dispersion calculated across four, six and eight segments (MD). Results: All RV wall-septum delays plus MD-4 and MD-6 indices were significantly greater in ToF patients compared to healthy controls (p < 0.001-0.03). In ToF patients, the lateral and anterior RV walls were last to reach peak deformation and anterior wall longitudinal strain was lower (p = 0.001). Post systolic shortening of at least one RV wall segment was identified in 19 (28%) ToF patients. Despite similar ECG characteristics, lateral and anterior wall-septum delays were significantly longer in patients with greater degrees of dyssynchrony (73 [37-108]ms vs. 37 [0-63]ms, p = 0.006; 91 [52-116]ms vs. 41 [1-69]ms, p = 0.013), although RV ejection fraction (RVEF) was not significantly lower. MD-4 and MD-8 indices displayed moderate negative associations with RVEF, strengthened by inclusion of lateral wall longitudinal strain (r = 0.64/0.65; p ≤0.01). Conclusion: RV dyssynchrony in ToF is characterised by electromechanical delays between the lateral, anterior and septal walls, with anterior wall dysfunction likely associated with surgical repair of the RV outflow tract. Prospectively, 2D-MPE may have an emerging role evaluating RV mechanical response to electrical resynchronisation therapy.