Search

Background Data related to electrophysiologic characteristics of atypical atrial flutter (AFL) following atrial fibrillation (AF) ablation and its prognostic value on repeat ablation success are limited. Methods We studied consecutive patients who underwent a repeat left atrial (LA) ablation procedure for either recurrent AF or atypical AFL, at least 3 months after index AF ablation, between January 2012 and July 2019. The demographics, clinical history, procedural data, complications, and 1-year arrhythmia-free survival rates were recorded for each subject after the first repeat ablation. Results A total of 336 patients were included in our study. Among these 336 patients, 102 underwent a repeat ablation procedure for atypical AFL and 234 underwent a repeat ablation procedure for recurrent AF. The mean age was 63.7 ± 10.7 years, and 72.6% of patients were men. The atypical AFL cohort had significantly higher LA diameters (4.6 vs. 4.4 cm, p = .04) and LA volume indices (LAVi; 85.1 vs. 75.4 ml/m2 , p = .03) compared to AF patients at repeat ablation. Atypical AFL patients were more likely to have had index radiofrequency (RF) ablation (as opposed to cryoballoon) than recurrent AF patients (98% vs. 81%, p = .01). Atypical AFLs were roof-dependent in 35.6% and peri-mitral in 23.8% of cases. Major complications at repeat ablation occurred in 0.9% of the total cohort. Arrhythmia-free survival at one year was significantly higher in the recurrent atypical AFL compared to the recurrent AF cohort (75.5 vs. 65.0%, p = .04). Conclusion In our series, roof-dependent flutter is the most common form of atypical atrial flutter post AF ablation. Patients developing atypical AFL after index AF ablation have greater LA dimensions than patients with recurrent AF. The success rate of first repeat ablation is significantly higher among patients with recurrent atypical AFL as compared to recurrent AF after index AF ablation.

Background: An estimated 1 million patients require cardiac implantable electronic devices (CIEDs) but go without annually. This disparity exists in low-to-middle-income nations largely owing to the cost of CIED hardware. Humanitarian reuse of CIEDs has been shown to be safe and feasible. However, recent publications have raised concern that promotion of CIED reuse may foster a CIED “black market,” to the dismay of manufacturers, regulators, and clinicians alike. Objective: To determine if unregulated CIED sales for potential human use is a real issue by investigating unregulated public online CIED sale listings in the United States of America. Methods: An observational study was undertaken over 6 months using multiple internet search engines from May 1 to November 1, 2019. We cataloged usable CIEDs (still in packaging, manufactured

A significant proportion of AF patients with advanced age are being treated in clinical practice. Cryoballoon ablation of AF, given its shorter procedure time and comparable efficacy to radiofrequency ablation, has rapidly become a commonly used tool for AF ablation. Data regarding the outcomes of cryoballoon ablation of AF in octogenarians are limited because of the exclusion of this age group in the previous studies. The authors report outcomes of 15 octogenarian AF patients undergoing index cryoballoon ablation at a single centre. The mean age of the included patients was 83 ± 3 years. In total, 13 patients (87%) presented with paroxysmal AF, and two (13%) had long-standing persistent AF. At 6 and 12 months of follow-up, freedom from AF was 80% and 70%, respectively. None of the patients suffered any procedure-related complications. Cryoballoon ablation appears to be a safe and effective approach for treating symptomatic AF refractory to antiarrhythmic drug therapy in octogenarian patients, based on outcomes in this cohort. These findings require further validation in prospective randomised studies with larger sample sizes.

Introduction: Despite advances in atrial fibrillation (AF) management, patients with AF continue to experience poor quality of life and adverse outcomes. Engagement of patients, caregivers, and clinicians to identify challenges in AF management can inform strategies to improve quality of life and improve AF related outcomes. Methods: We conducted virtual Human Centered Design (HCD) sessions with a) patients with AF and their caregivers to understand challenges in living with AF, and b) clinicians caring for patients with AF to identify difficulties encountered in AF management. During HCD sessions, we engaged participants to answer open-ended questions. Transcripts of audio recorded sessions were coded and emerging themes were identified. Results: 8 patients (25% African American, 13% Asian), 3 caregivers, and 7 clinicians participated in HCD sessions. Median (interquartile range) patient age was 69 years (58 - 78). Major themes from the patient and caregiver perspective included inadequate education on AF, lack of guidance on AF risk factor modification, lack of support networks, and absence of systems to guide patients when experiencing recurrent AF episodes. Major themes from the clinician perspective were complementary to patient and caregiver input. Themes included inadequate patient education due to limited time clinicians can spend with patients, lack of AF risk factor modification programs, and lack of streamlined services to allow timely communication with patients without increasing the administrative burden for physicians (Figure 1). Conclusions: A diverse group of patients, their caregivers, and clinicians identified lack of adequate education, guidance on AF risk factor modification as well as poorly structured patient-clinician communication as major challenges in AF care. Our findings are informing development of mobile health application addressing identified challenges with a goal to improve quality of life and adverse AF outcomes.

Introduction: Increasing numbers of elderly patients are undergoing catheter ablation (CA) of atrial fibrillation (AF). However, data regarding the experience with this procedure in the octogenarians are limited. Objective: To describe safety and efficacy of index CA of AF and predictors of arrhythmia recurrence in octogenarians. Methods: We conducted a retrospective analysis of patients > 80 years old undergoing index AF ablation between 2012 and 2020 at a large academic medical center. Procedural complications and efficacy, defined as freedom from any atrial tachyarrhythmia (ATA) lasting ≥30 seconds, were assessed. All patients were followed for at least 1 year. Predictors of ATA recurrence were also evaluated. Results: A total of 69 patients were included in our analysis. The median age was 82 (81-85) years, 53.6% were men, and 36.2% had persistent AF (PsAF). The mean left atrial (LA) diameter was 4.3 + 0.8 cm, while the median CHA 2 DS 2 -VASc score was 4 (3-4.5). The majority (n=48, 69.6%) underwent radiofrequency ablation, and the remaining (n=21, 30.4%) patients underwent cryoballoon ablation. Pulmonary vein (PV) isolation was performed in all patients, and 31 (44.9%) patients underwent additional non-PV ablation. None of the patients developed any procedural complications. Acute procedural success with PV isolation was achieved in all the patients, and a total of 44 (63.8%) patients remained free of ATA at 1-year of follow-up. Among the patients with ATA recurrence, 24 (34.8%) were on antiarrhythmic drugs, and 12 (17.4%) patients underwent repeat ablation. Anticoagulation was continued in all the patients. In a multivariable model, only AF type (PsAF) was associated with ATA recurrence at 1-year follow-up (HR=3.42, CI: 1.17-9.94, p=0.02). Conclusion: CA of AF appears to be a safe and effective procedure in octogenarians. AF type (PsAF) is an independent predictor of ATA recurrence at 1-year follow-up.

Introduction: Atrial fibrillation (AF) is a common in patients with heart failure with preserved ejection fraction (HFpEF), and is associated with higher filling pressures, reduced exercise capacity, and reduced survival. The prevalence of subclinical AF in HFpEF remains unknown. Hypothesis: We hypothesized that subclinical AF was more prevalent in individuals with HFpEF when compared to individuals without clinical heart failure history. Methods: We evaluated subclinical AF in 101 HFpEF patients with no prior diagnosis of clinical AF using 14 day ambulatory ECG patch monitoring (Ziopatch XT, iRhythm Technologies). We compared the prevalence of subclinical AF in HFpEF with controls drawn from 3303 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) exam 6 follow-up, excluding those with known heart failure or high H2FpEF score who underwent the same ECG patch monitoring. Case-control comparisons of participants between the ages of 55 to 93 years were performed using multivariable logistic regression to adjust for demographic and clinical comorbidities, as well as patch monitoring duration. Results: 80 HFpEF patients and 1356 MESA participants were included. The HFpEF patients were younger (69 [63, 76] v. 72 [66, 80], p=0.02), more obese (BMI of 36 [30, 45] v. 27 [24, 30], p Conclusions: HFpEF patients have a higher prevalence of subclinical AF than the general population. Screening for atrial arrhythmias may be appropriate in HFpEF patients for timely initiation of thromboembolic prophylaxis, and may identify individuals at greater risk for clinical decompensation in light of the well documented risks associated with AF in HFpEF.

Background Transesophageal echocardiography (TEE) is variably performed before atrial fibrillation (AF) ablation to evaluate left atrial appendage (LAA) thrombus. We describe our experience with transitioning to the pre-ablation cardiac computed tomography (CT) approach for the assessment of LAA thrombus during the COVID-19 pandemic. Methods We studied consecutive patients undergoing AF ablation at our center. The study cohort was divided into pre- vs. post-COVID groups. The pre-COVID cohort included ablations performed during 1 year before the COVID-19 pandemic; pre-ablation TEE was used routinely to evaluate LAA thrombus in high-risk patients. Post-COVID cohort included ablations performed during the 1 year after the COVID-19 pandemic; pre-ablation CT was performed in all patients, with TEE performed only in patients with LAA thrombus by CT imaging. The demographics, clinical history, imaging, and ablation characteristics, and peri-procedural cerebrovascular events (CVE) were recorded. Results A total of 637 patients (pre-COVID n=424, post-COVID n=213) were studied. The mean age was 65.6  10.1 years in the total cohort, and the majority were men. There was a significant increase in pre-ablation CT imaging from pre to post-COVID cohort (74.8 vs. 93.9%, p=

Aims Inadequate modification of the atrial fibrotic substrate necessary to sustain re-entrant drivers (RDs) may explain atrial fibrillation (AF) recurrence following failed pulmonary vein isolation (PVI). Personalized computational models of the fibrotic atrial substrate derived from late gadolinium enhanced (LGE)-magnetic resonance imaging (MRI) can be used to non-invasively determine the presence of RDs. The objective of this study is to assess the changes of the arrhythmogenic propensity of the fibrotic substrate after PVI. Methods and results Pre- and post-ablation individualized left atrial models were constructed from 12 AF patients who underwent pre- and post-PVI LGE-MRI, in six of whom PVI failed. Pre-ablation AF sustained by RDs was induced in 10 models. RDs in the post-ablation models were classified as either preserved or emergent. Pre-ablation models derived from patients for whom the procedure failed exhibited a higher number of RDs and larger areas defined as promoting RD formation when compared with atrial models from patients who had successful ablation, 2.6 ± 0.9 vs. 1.8 ± 0.2 and 18.9 ± 1.6% vs. 13.8 ± 1.5%, respectively. In cases of successful ablation, PVI eliminated completely the RDs sustaining AF. Preserved RDs unaffected by ablation were documented only in post-ablation models of patients who experienced recurrent AF (2/5 models); all of these models had also one or more emergent RDs at locations distinct from those of pre-ablation RDs. Emergent RDs occurred in regions that had the same characteristics of the fibrosis spatial distribution (entropy and density) as regions that harboured RDs in pre-ablation models. Conclusion Recurrent AF after PVI in the fibrotic atria may be attributable to both preserved RDs that sustain AF pre- and post-ablation, and the emergence of new RDs following ablation. The same levels of fibrosis entropy and density underlie the pro-RD propensity in both pre- and post-ablation substrates.

The purpose of this study was to evaluate the usefulness of intra-atrial dyssynchrony as a marker of underlying left atrial (LA) remodeling to predict recurrence after the first atrial fibrillation (AF) ablation.Catheter ablation for AF remains far from curative with relatively high recurrence rates. One of the causes of recurrence is poor patient selection out of a diverse patient population with different degrees of LA remodeling.We included 208 patients with a history of AF (59.4 ± 10.0 years of age; 26.0% nonparoxysmal AF) referred for catheter ablation of AF who underwent pre-ablation cardiac magnetic resonance in sinus rhythm. Clinical follow-up was 20 ± 6 months. Using tissue tracking cardiac magnetic resonance, we measured the LA longitudinal strain in each of 12 equal-length segments in 2- and 4-chamber views. We defined intra-atrial dyssynchrony as the standard deviation of the time to the peak longitudinal strain corrected by the cycle length (SD-time to peak strain [TPS], %).Patients with AF recurrence after ablation (n = 101) had significantly higher SD-TPS than those without (n = 107; 3.9% vs. 2.2%; p 0.001). Multivariable cox analysis showed that SD-TPS was associated with recurrence after adjusting for clinical risk factors, AF type, LA structure and function, and fibrosis (p 0.001). Furthermore, receiver-operating characteristics analysis showed SD-TPS improved prediction of recurrence better than clinical risk factors, LA structure and function, and fibrosis.Intra-atrial dyssynchrony during sinus rhythm is an independent predictor of recurrence after the first catheter ablation of paroxysmal or persistent AF. Assessment of intra-atrial dyssynchrony may improve ablation outcomes by refining patient selection.

Objectives The aim of the current investigation is to examine whether use of high-frequency jet ventilation (HFJV) during pulmonary vein isolation (PVI) performed with force-sensing catheters is associated with improved outcomes. Background Catheter ablation is well established as therapy for symptomatic atrial fibrillation (AF). Reconnection following PVI is commonly observed during repeat ablation procedures. Technologies that may optimize catheter stability and lesion delivery include both force-sensing ablation catheters and HFJV. Methods Patients undergoing PVI at Johns Hopkins Hospital were prospectively enrolled in a registry. The study compared procedural characteristics, adverse event rates, and 1-year procedural outcomes in patients undergoing PVI supported either by standard ventilation or HFJV. Patient and procedural aspects were otherwise constant. Results Eighty-four HFJV patients and 84 matched control patients with 1-year outcome data were identified. Atrial arrhythmia recurrence occurred in 26 of 84 HFJV patients (31%) and 42 of 84 control patients (50%; p = 0.019). In patients with paroxysmal AF, arrhythmia recurrence in HFJV and control patients was 27.3% and 47.3%, respectively (p = 0.045). In patients with persistent AF, arrhythmia recurrence rates were not significantly different (37.9% in HFJV patients, 55.2% in control patients; p = 0.184). On multivariate analysis, HFJV was independently associated with improved freedom from arrhythmia recurrence. Vasopressor use during HFJV cases was significantly higher than during standard ventilation (79.7% vs. 22.4%; p = 0.001). Indices of catheter stability and contact force adequacy were significantly higher in the HFJV patients than in control patients. Complication rates in the 2 groups were similarly low. Conclusions Use of HFJV in patients undergoing PVI with radiofrequency force-sensing catheters is associated with improved outcomes, without appreciable increase in adverse procedural events.

BACKGROUND: Whether rhythm control for post-operative atrial fibrillation after cardiac surgery (POAF) is superior to rate control in patients with heart failure or systolic dysfunction (HF) is not known. METHODS: We performed a post-hoc analysis of a trial by the Cardiothoracic Surgical Trials Network, which randomized patients with POAF after cardiac surgery to rate control or rhythm control with amiodarone/cardioversion. We assessed subgroups of trial participants defined by heart failure/cardiomyopathy history or left ventricular ejection fraction (LVEF) < 50%. We conducted a stratified analysis in patients with and without HF to explore outcomes of rhythm versus rate control strategy. RESULTS: Of 523 subjects with POAF after cardiac surgery, 131 (25%) had HF. 49% of HF patients were randomized to rhythm control. In HF patients, rhythm control was associated with less atrial fibrillation within the first 7 days. There were no differences in rhythm at 30- and 60-day followup. In the HF group, there were significantly more subjects with AF < 48 hours in the rhythm control group compared to rate control group- 68.8% compared to 46.3%, P=0.009. By comparison, in the non-HF stratum, 54.4% of the rate control group had AF < 48 hours compared to 63.5% of the rhythm control group (P=0.067). ), though there was no significant interaction of heart failure with cardiac rhythm at 7 days (Pinteraction 0.16). CONCLUSION: Rhythm control for HF patients with POAF after cardiac surgery increases early restoration of sinus rhythm. Rate and rhythm control are both reasonable for HF patients with AF after cardiac surgery

Introduction: Catheter ablation (CA) for atrial fibrillation (AF) is widely performed, with a rising proportion of patients of advanced age receiving the procedure. There are limited data describing the experience of index radiofrequency (RF) vs. cryoballoon (CB) ablation for AF among elderly patients in the United States. Hypothesis: CB ablation is associated with better outcomes in elderly patients. Methods: We conducted a retrospective analysis of patients > 75 years undergoing index AF ablation between January 2001 and March 2019 at our center. Major complications and efficacy, defined as freedom from any atrial tachyarrhythmia (ATA) lasting ≥30 seconds after 1 year of follow-up, were assessed in patients with index RF vs. CB ablation. Predictors of ATA recurrence at 1year follow-up were also evaluated. Results: In our cohort of 194 patients, the mean age was 78 + 3.1 years, 58.2% were men, and 39.4% had persistent AF. The mean left atrial (LA) diameter was 4.5 + 0.7, while mean CHA2DS2-VASc score was 3.5 + 1.2. The majority (n=149, 76.8%) underwent RF ablation. The incidence of major complications, including bleeding and cardiac tamponade, was similar in the two sub-groups (RF: 2% vs. CB: 0%, p=0.63). No significant difference in success rate at 1year follow-up was found between patients receiving RF vs. CB ablation (57.7% vs. 64.4% Figure, p=0.94). In a multivariable model adjusting for the age, sex, CHA 2 DS 2 -VASc score, AF type, and index RF vs CB ablation, only LA size was associated with ATA recurrence at 1 year follow-up with each increment of 1 cm in LA size was associated with 1.6-fold greater risk of recurrence [HR=1.59, CI: 1.05-2.41, p=0.02]. Conclusion: In elderly patients undergoing index CA for AF, RF ablation was the predominant modality with similar safety and efficacy relative to CB ablation. LA size was the significant predictor of ATA recurrence at 1year independent of index ablation modality.

Introduction: Atrial fibrillation (AF) patients are at high risk of stroke, with the left atrial appendage (LAA) found to be the most common site of clot formation. Left atrial (LA) fibrosis is also associated with higher stroke risk. However, the mechanisms for increased stroke risk in patients with atrial fibrotic remodeling are poorly understood. We sought to explore these specific mechanisms using fluid dynamics analysis. Hypothesis: The presence of LA fibrosis leads to aberrant hemodynamics in the atria, contributing to increased stroke risk in AF patients. Methods: We retrospectively collected LGE-MRI images of 3 AF patients and reconstructed their 3D LA endocardial surfaces. Fibrotic regions were identified as those with intensity 3 standard deviations greater than the mean LA blood-pool intensity. Personalized computational fluid dynamic simulations were performed, and hemodynamics at the LA wall were quantified by wall shear stress (WSS, friction of blood) and oscillatory shear index (OSI, temporal directional change of WSS). For each case, WSS and OSI were compared between fibrotic and normal regions. Results: WSS was significantly lower in the fibrotic region as compared to normal region for all 3 cases. Additionally, OSI was higher in the fibrotic region as compared to normal region for all 3 cases. However, this different was statistically significant for cases 1 and 3; case 2 was not statistically significantly different. Low WSS and high OSI in the vicinity of the fibrotic wall suggest that local blood-flow was slow and oscillating, enabling pro-thrombotic conditions for circulating blood. Conclusion: LA fibrosis correlates with regions of aberrant hemodynamics, which renders it susceptible to blood thrombosis. AF patients with high LA fibrosis burden will have more pro-thrombotic regions, in addition to low flow in the LAA, providing more sites for a potential clot formation. These conditions might get exacerbated during an AF event and cause stroke.

Introduction: Left atrial appendage (LAA) is the primary source of clot formation that can cause stroke or transient ischemic attack (TIA) in patients with atrial fibrillation (AF). LAA closure devices have emerged as alternatives to traditional anticoagulation therapy for reducing stroke risk in AF patients. However, ~1-2% of AF patients undergoing LAA closure have subsequent stroke/TIA event. Hypothesis: The presence of a persistent low-flow zone in LA, distinct from LAA, explains why some patients have stroke/TIA events after LAA closure. Methods: We developed a personalized stroke risk prediction tool that uses patient’s CT image to perform computational fluid dynamics simulation and determine presence of low blood-flow in the LA before and after LAA closure. Low flow is quantified by the establishment of low velocity fraction (LVF) in the LA volume, and low wall shear stress fraction (LWSSF) on the surface of the LA wall. The tool was applied retrospectively on 4 AF patients who had undergone LAA closure: 2 patients with TIA 4 months after LAA closure, and 2 controls matched for age, gender, CHA2DS2-VASc score and LAA dimensions with no complications at follow-up up to 2 years. Results: Before LAA closure, TIA and control groups had similar LVF (0.07 and 0.06, respectively) and LWSSF (0.12 and 0.16, respectively). However, after LAA closure, the TIA group had smaller reductions as compared to controls in both LVF (67% vs 79%) and LWSSF (17% vs 52%). This suggests that the LA low-flow region (especially at LA wall) was not substantially reduced after LAA closure, explaining why these patients might have experienced TIA. Conclusion: This proof-of-concept study demonstrates that LAA closure might not substantially reduce low-flow zones for all AF patients, as some retain low-flow zones in LA. Our stroke prediction tool has the potential to identify patients at risk of future stroke/TIA, thus enabling personalized patient selection to increase efficacy of LAA closure devices.

Background The effects of atrial fibrillation (AF) catheter ablation on the left atrium (LA) are poorly understood. Objectives To examine short and long-term associations of AF catheter ablation with LA function using cardiac magnetic resonance (CMR). Methods Fifty-one AF patients (mean age 56±8 years) underwent CMR at baseline, 1 day (n=17) and 11±2 months after ablation (n=38). LA phasic volumes, emptying fractions (LAEF), and longitudinal strain were measured using feature-tracking CMR. LA fibrosis was quantified using late gadolinium enhancement (LGE). Results There were no acute changes in volume, however, active, total LAEF, and peak LA strain decreased significantly compared to the baseline. During long-term follow-up, there was a decrease in maximum but not minimum LA volume (from 99±5.2ml to 89±4.7ml, p=0.009) and a decrease in total LAEF (from 43±1.8% to 39±2.0%, p=0.001). In patients with AF recurrence, LA volumes were unchanged. However, total LAEF decreased from 38±3% to 33±3%; p=0.015. Patients without AF recurrence had no changes in LA functional parameters during follow-up. The amount of LA LGE at long term follow-up was higher compared to the baseline, however was significantly less compared to immediately post procedure (37±1.9 % vs. 47±2.8%, p=0.015). A higher increase in LA LGE extent compared to the baseline was associated with a greater decrease in total LAEF (r=-0.59, p Conclusions LA function is impaired acutely following AF catheter ablation. However, long-term changes of LA function are associated positively with successful restoration of sinus rhythm and inversely with increased LA LGE. This article is protected by copyright. All rights reserved.

Introduction Advanced interatrial block (IAB) on a 12‐lead electrocardiogram (ECG) is a predictor of stroke, incident atrial fibrillation (AF), and AF recurrence after catheter ablation. The objective of this study was to determine which features of IAB structural remodeling is associated with left atrium (LA) magnetic resonance imaging structure and function. Methods/Results We included 152 consecutive patients (23% nonparoxysmal AF) who underwent preprocedural ECG and cardiac magnetic resonance (CMR) in sinus rhythm before catheter ablation of AF. IAB was defined as P‐wave duration ≥120 ms, and was considered partial if P‐wave was positive and advanced if P‐wave had a biphasic morphology in inferior leads. From cine CMR and late gadolinium enhancement, we derived LA maximum and minimum volume indices, strain, LA fibrosis, and LA dyssynchrony. A total of 77 patients (50.7% paroxysmal) had normal P‐wave, 52 (34.2%) partial IAB, and 23 (15.1%) advanced IAB. Patients with advanced IAB had significantly higher LA minimum volume index (25.7 vs 19.9 mL/m2, P = .010), more LA fibrosis (21.9% vs 13.1%, P = .020), and lower LA maximum strain rate (0.99 vs 1.18, P = .007) than those without. Advanced IAB was independently associated with LA (minimum [P = .032] and fibrosis [P = .009]). P‐wave duration was also independently associated with LA fibrosis (β = .33; P = .049) and LA mechanical dyssynchrony (β = 2.01; P = .007). Conclusion Advanced IAB is associated with larger LA volumes, lower emptying fraction, and more fibrosis. Longer P‐wave duration is also associated with more LA fibrosis and higher LA mechanical dyssynchrony. Sin financiación 2.871 JCR (2020) Q3, 79/142 Cardiac & Cardiovascular Systems 1.193 SJR (2020) Q1, 72/349 Cardiology and Cardiovascular Medicine No data IDR 2020 UEM

Background: Pulmonary vein isolation (PVI) is an effective treatment strategy for patients with atrial fibrillation (AF), but many experience AF recurrence and require repeat ablation procedures. The goal of this study was to develop and evaluate a methodology that combines machine learning (ML) and personalized computational modeling to predict, before PVI, which patients are most likely to experience AF recurrence after PVI. Methods: This single-center retrospective proof-of-concept study included 32 patients with documented paroxysmal AF who underwent PVI and had preprocedural late gadolinium enhanced magnetic resonance imaging. For each patient, a personalized computational model of the left atrium simulated AF induction via rapid pacing. Features were derived from pre-PVI late gadolinium enhanced magnetic resonance images and from results of simulations of AF induction. The most predictive features were used as input to a quadratic discriminant analysis ML classifier, which was trained, optimized, and evaluated with 10-fold nested cross-validation to predict the probability of AF recurrence post-PVI. Results: In our cohort, the ML classifier predicted probability of AF recurrence with an average validation sensitivity and specificity of 82% and 89%, respectively, and a validation area under the curve of 0.82. Dissecting the relative contributions of simulations of AF induction and raw images to the predictive capability of the ML classifier, we found that when only features from simulations of AF induction were used to train the ML classifier, its performance remained similar (validation area under the curve, 0.81). However, when only features extracted from raw images were used for training, the validation area under the curve significantly decreased (0.47). Conclusions: ML and personalized computational modeling can be used together to accurately predict, using only pre-PVI late gadolinium enhanced magnetic resonance imaging scans as input, whether a patient is likely to experience AF recurrence following PVI, even when the patient cohort is small.

Our world is faced with a global pandemic that threatens to overwhelm many national health care systems for a prolonged period. Consequently, the elective long-term cardiac implantable electronic device (CIED) management of millions of patients is potentially compromised, raising the likelihood of patients experiencing major adverse events owing to loss of CIED therapy. This review gives practical guidance to health care providers to help promptly recognize the requirement for expert consultation for urgent interrogation and/or surgery in CIED patients.

Objectives This study aimed to determine the long-term outcomes and predictors of left ventricular (LV) ejection fraction (LVEF) improvement in patients with severe cardiomyopathies undergoing cardiac resynchronization therapy (CRT). Background Whether patients with severe LV dysfunction benefit from CRT or have reached a point in disease severity past the point at which CRT is beneficial is unknown. Methods We collected clinical and echocardiographic data on 420 patients with an LVEF of ≤15% and a QRS duration of ≥120 ms undergoing CRT at the Cleveland Clinic and 2 hospitals in the Johns Hopkins Health System between April 2003 and May 2014. Multivariate models were created to determine factors associated with response to CRT, defined as an absolute improvement in LVEF of >5% and survival free of LVAD and heart transplant. Procedure-related deaths were also collected. Results A total of 298 patients had pre- and appropriately timed post-CRT echocardiograms, of whom 145 (48.7%) met the criteria for response. In multivariate analysis, LV size and left bundle branch block (LBBB) were associated with response. Among the most dilated quintile (LV end-diastolic diameter [LVEDD] of >7.8 cm), 30.4% met the criteria for response. In multivariate analysis, smaller LV end-diastolic dysfunction and presence of LBBB were associated with improved survival free of heart failure and LVAD over a mean follow-up period of 5.2 years. There were no procedure-related deaths. Conclusions Patients with severe LV dysfunction respond to CRT, although at a lower rate compared to traditional CRT candidates. Smaller LV size and LBBB are important predictors of positive outcomes in this population. Even among the most dilated patients, 30.4% realized a meaningful improvement in LVEF with CRT. The CRT implant procedure itself appears well tolerated.

Background Patients go without pacemaker, defibrillator, and cardiac resynchronization therapies (devices) each year due to the prohibitive costs of devices. Objective We sought to examine data available from studies regarding contemporary risks of reused devices in comparison with new devices. Methods We searched online indexing sites to identify recent studies. Peer-reviewed manuscripts reporting infection, malfunction, premature battery depletion, and device-related death with reused devices were included. The primary study outcome was the composite risk of infection, malfunction, premature battery depletion, and death. Secondary outcomes were the individual risks. Results Nine observational studies (published 2009-2017) were identified totaling 2,302 devices (2,017 pacemakers, 285 defibrillators). Five controlled trials were included in meta-analysis (2,114 devices; 1,258 new vs 856 reused). All device reuse protocols employed interrogation to confirm longevity and functionality, disinfectant therapy, and, usually, additional biocidal agents, packaging, and ethylene oxide gas sterilization. Demographic characteristics, indications for pacing, and median follow-up were similar. There were no device-related deaths reported and no statistically significant difference in risk between new versus reused devices for the primary outcome (2.23% vs 3.86% respectively, P = 0.807, odds ratio = 0.76). There were no significant differences seen in the secondary outcomes for the individual risks of infection, malfunction, and premature battery depletion. Conclusions Device reuse utilizing modern protocols did not significantly increase risk of infection, malfunction, premature battery depletion, or device-related death in observational studies. These data provide rationale for proceeding with a prospective multicenter noninferiority randomized control trial.

Objectives The aim of this study was to examine atrial fibrillation (AF) substrate using different modalities (point-by-point [PBP], fast anatomic mapping [FAM], and late gadolinium enhancement [LGE] magnetic resonance imaging [MRI] mapping) in patients presenting for AF ablation. Background Bipolar voltage mapping, as part of AF ablation, is traditionally performed in a PBP approach using single-tip ablation catheters. Alternative techniques for fibrosis delineation include FAM with multi-electrode circular catheters and LGE MRI. The correlation between PBP, FAM, and LGE-MRI fibrosis assessment is unknown. Methods LGE MRI was performed pre-ablation in 26 patients (73% men, mean age 63 ± 8 years). Local image intensity ratio (IIR) was used to normalize myocardial intensities. PBP and FAM voltage maps were acquired, in sinus rhythm, prior to ablation and coregistered with LGE MRI. Results The mean bipolar voltage for all 19,087 FAM voltage points was 0.88 ± 1.27 mV, and the average IIR was 1.08 ± 0.18. In an adjusted mixed-effects model, each unit increase in local IIR was associated with a 57% decrease in bipolar voltage (p 0.74 corresponded to a bipolar voltage Conclusions LGE-MRI, FAM, and PBP mapping showed good correlation in delineating electroanatomic AF substrate. Each approach has fundamental technical characteristics, the awareness of which allows proper assessment of atrial fibrosis.

Background: Cardiac resynchronization therapy (CRT) has significant nonresponse rates. We assessed whether machine learning (ML) could predict CRT response beyond current guidelines. Methods: We analyzed CRT patients from Cleveland Clinic and Johns Hopkins. A training cohort was created from all Johns Hopkins patients and an equal number of randomly sampled Cleveland Clinic patients. All remaining patients comprised the testing cohort. Response was defined as ≥10% increase in left ventricular ejection fraction. ML models were developed to predict CRT response using different combinations of classification algorithms and clinical variable sets on the training cohort. The model with the highest area under the curve was evaluated on the testing cohort. Probability of response was used to predict survival free from a composite end point of death, heart transplant, or placement of left ventricular assist device. Predictions were compared with current guidelines. Results: Nine hundred twenty-five patients were included. On the training cohort (n=470: 235, Johns Hopkins; 235, Cleveland Clinic), the best ML model was a naive Bayes classifier including 9 variables (QRS morphology, QRS duration, New York Heart Association classification, left ventricular ejection fraction and end-diastolic diameter, sex, ischemic cardiomyopathy, atrial fibrillation, and epicardial left ventricular lead). On the testing cohort (n=455, Cleveland Clinic), ML demonstrated better response prediction than guidelines (area under the curve, 0.70 versus 0.65; P =0.012) and greater discrimination of event-free survival (concordance index, 0.61 versus 0.56; P P Conclusions: ML with 9 variables incrementally improved prediction of echocardiographic CRT response and survival beyond guidelines. Performance was not improved by incorporating more variables. The model offers potential for improved shared decision-making in CRT (online calculator: http://riskcalc.org:3838/CRTResponseScore ). Significant remaining limitations confirm the need to identify better variables to predict CRT response.

Background: Previous studies showed that the quantity of the left atrial (LA) periatrial fat tissue predicts recurrence after catheter ablation of atrial fibrillation (AF). We hypothesized that the quality of the LA periatrial fat tissue, measured by the mean computed tomography attenuation, predicts recurrence after AF ablation independent of the quantity of the LA periatrial fat tissue. Methods: We included 143 consecutive patients with drug-refractory AF referred for the first catheter ablation of AF (62.2±10 years, 40% nonparoxysmal AF). All participants had a preablation cardiac computed tomography. We measured the quantity of the LA periatrial fat tissue by the area (millimeter square) and the quality by the mean computed tomography attenuation (Hounsfield units) in a standard 4-chamber view. Results: Patients with AF recurrence after ablation (n=57) had a significantly larger fat area (167.6 [interquartile range, 124.1–255] versus 145.4 [95.6–229.3] mm 2 ; P =0.018) and a higher fat attenuation (−92.0±9.8 versus −96.5±9.4 Hounsfield units; P =0.006) than those without recurrence (controls). LA fat attenuation was correlated with LA fat volume and LA bipolar voltage by invasive mapping and was associated with AF recurrence after adjusting for clinical risk factors, including body mass index, AF type, LA dimension, and fat area (hazard ratio, 2.65; P =0.001). Conclusions: The quality of the LA periatrial fat tissue is an independent predictor of recurrence after the first AF ablation. Assessment of LA periatrial fat attenuation can improve AF ablation outcomes by refining patient selection.

The aims of this study were to: 1) use a novel method of late gadolinium enhancement (LGE) quantification that uses normalized intensity measures to confirm the association between LGE extent and atrial fibrillation (AF) recurrence following ablation; and 2) examine the presence of interaction and effect modification between LGE and AF persistence.Recurrent AF after catheter ablation has been reported to associate with the baseline extent of left atrial LGE on cardiac magnetic resonance. Traditional methods for measurement of intensity lack an objective threshold for quantification and interpatient comparisons of LGE.The cohort included 165 participants (mean age 60.0 ± 10.2 years, 77% men, 57% with persistent AF) who underwent initial AF ablation. The association of baseline LGE extent with AF recurrence was examined using multivariable Cox proportional hazards models. Multiplicative and additive interactions between AF type and LGE extent were examined.During 10.2 ± 5.7 months of follow-up, 63 patients (38.2%) experienced AF recurrence. Baseline LGE extent was independently associated with AF recurrence after adjusting for confounders (hazard ratio: 1.5 per 10% increased LGE; p 0.001). The hazard ratio for AF recurrence progressively increased as a function of LGE. The magnitude of association between LGE35% and AF recurrence was greater among patients with persistent AF (hazard ratio: 6.5 [p = 0.001] vs. 3.6 [p = 0.001]); however, there was no evidence for statistical interaction.Regardless of AF persistence at baseline, participants with LGE ≤35% have favorable outcomes, whereas those with LGE35% have a higher rate of AF recurrence in the first year after ablation. These findings suggest a role for: 1) patient selection for AF ablation using LGE extent; and 2) substrate modification in addition to pulmonary vein isolation in patients with LGE extent exceeding 35% of left atrial myocardium.

Symptomatic left atrial (LA) flutter (LAFL) is common after atrial fibrillation (AF) ablation.The purpose of this study was to examine the association of baseline LA function with incident LAFL after AF ablation.The source cohort included 216 patients with cardiac magnetic resonance (CMR) before initial AF ablation between 2010 and 2013. Patients who underwent cryoballoon or laser ablation, patients with AF during CMR, and those with suboptimal CMR, or missing follow-up data were excluded. Baseline LA volume and function were assessed by feature-tracking CMR analysis.The final cohort included 119 patients (mean age 58.9 ± 11 years; 76.5% men; 70.6% patients with paroxysmal AF). During a median follow-up of 421 days (interquartile range 235-751 days), 22 patients (18.5%) had incident LAFL. Baseline LA volume was similar between the 2 groups. In contrast, baseline reservoir, conduit, and contractile function of the LA were significantly impaired in patients with incident LAFL. Baseline global peak longitudinal atrial strain (PLAS)22.65% predicted incident LAFL with 86% sensitivity and 68% specificity (C statistic 0.76). In a multivariable model adjusting for age, heart failure, and LA volume, PLAS (hazard ratio 0.9 per % increase in PLAS; P = .003) and LA linear lesions (hazard ratio 2.94; P = .020) were independently associated with incident LAFL. The coexistence of PLAS22.65% and linear lesions was associated with 9-fold increased hazard of incident LAFL.Baseline LA function and linear lesions were independently associated with incident LAFL after AF ablation. Linear lesions should be limited to selected cases, especially in patients with impaired LA function.

Whether rhythm control for post-operative atrial fibrillation after cardiac surgery (POAF) is superior to rate control in patients with heart failure (HF) is not known. We performed a post-hoc analysis of a trial by the Cardiothoracic Surgical Trials Network, which randomized patients with POAF to

Background: Recent studies suggest that left atrial (LA) late gadolinium enhancement (LGE) can quantify the underlying tissue remodeling that harbors atrial fibrillation (AF). However, quantification of LA-LGE requires labor-intensive magnetic resonance imaging acquisition and postprocessing at experienced centers. LA intra-atrial dyssynchrony assessment is an emerging imaging technique that predicts AF recurrence after catheter ablation. We hypothesized that 1) LA intra-atrial dyssynchrony is associated with LA-LGE in patients with AF and 2) LA intra-atrial dyssynchrony is greater in patients with persistent AF than in those with paroxysmal AF. Method: We conducted a cross-sectional study comparing LA intra-atrial dyssynchrony and LA-LGE in 146 patients with a history of AF (60.0 ± 10.0 years, 30.1% nonparoxysmal AF) who underwent pre-AF ablation cardiac magnetic resonance (CMR) in sinus rhythm. Using tissue-tracking CMR, we measured the LA longitudinal strain in two- and four-chamber views. We defined intra-atrial dyssynchrony as the standard deviation (SD) of the time to peak longitudinal strain (SD-TPS, in %) and the SD of the time to the peak pre-atrial contraction strain corrected by the cycle length (SD-TPSpreA, in %). We used the image intensity ratio (IIR) to quantify LA-LGE. Results: Intra-atrial dyssynchrony analysis took 5 ± 9 minutes per case. Multivariable analysis showed that LA intra-atrial dyssynchrony was independently associated with LA-LGE. In addition, LA intra-atrial dyssynchrony was significantly greater in patients with persistent AF than those with paroxysmal AF. In contrast, there was no significant difference in LA-LGE between patients with persistent and paroxysmal AF. LA intra-atrial dyssynchrony showed excellent reproducibility and its analysis was less time-consuming (5 ± 9 minutes) than the LA-LGE (60 ± 20 minutes). Conclusion: LA Intra-atrial dyssynchrony is a quick and reproducible index that is independently associated with LA-LGE to reflect the underlying tissue remodeling. Resumo Fundamento: Estudos recentes sugerem que o realce tardio com gadolínio (RTG) no átrio esquerdo (AE) pode quantificar a remodelação tecidual subjacente que abriga a fibrilação atrial (FA). No entanto, a quantificação do RTG-AE requer um trabalho intenso de aquisição por ressonância magnética e pós-processamento em centros experientes. A avaliação da dessincronia intra-atrial no AE é uma técnica de imagem emergente que prediz a recorrência da FA após ablação por cateter. Nós levantamos as hipóteses de que 1) a dessincronia intra-atrial está associada ao RTG-AE em pacientes com FA e 2) a dessincronia intra-atrial é maior em pacientes com FA persistente do que naqueles com FA paroxística. Método: Realizamos um estudo transversal comparando a dessincronia intra-atrial no AE e o RTG-AE em 146 pacientes com história de FA (60,0 ± 10,0 anos, 30,1% com FA não paroxística) submetidos à ressonância magnética cardíaca (RMC) durante ritmo sinusal antes da ablação da FA. Com utilização de RMC com tissue tracking, medimos o strain longitudinal do AE em cortes de duas e quatro câmaras. Definimos a dessincronia intra-atrial como o desvio padrão (DP) do tempo até o pico do strain longitudinal (DP-TPS, em %) e o DP do tempo até o pico do strain antes da contração atrial corrigido pela duração do ciclo (DP-TPSpreA, em %). Utilizamos a razão da intensidade da imagem (RIM) para quantificar o RTG-AE. Resultados: A análise da dessincronia intra-atrial levou 9 ± 5 minutos por caso. A análise multivariada mostrou que a dessincronia intra-atrial no AE esteve independentemente associada ao RTG-AE. Além disso, a dessincronia intra-atrial no AE foi significativamente maior em pacientes com FA persistente do que naqueles com FA paroxística. Por outro lado, não houve diferença significativa no RTG-AE entre pacientes com FA persistente e paroxística. A dessincronia intra-atrial no AE mostrou excelente reprodutibilidade e sua análise foi menos demorada (5 ± 9 minutos) do que o RTG-AE (60 ± 20 minutos). Conclusão: A dessincronia intra-atrial no AE é um índice rápido, reprodutível e independentemente associado ao RTG-AE para indicar remodelação tecidual subjacente. (Arq Bras Cardiol. 2019; 112(4):441-450)

Atrial fibrillation (AF)-the most common arrhythmia-significantly increases the risk of stroke and heart failure. Although catheter ablation can restore normal heart rhythms, patients with persistent AF who develop atrial fibrosis often undergo multiple failed ablations, and thus increased procedural risks. Here, we present personalized computational modelling for the reliable predetermination of ablation targets, which are then used to guide the ablation procedure in patients with persistent AF and atrial fibrosis. First, we show that a computational model of the atria of patients identifies fibrotic tissue that, if ablated, will not sustain AF. Then, we report the results of integrating the target ablation sites in a clinical mapping system and testing its feasibility in ten patients with persistent AF. The computational prediction of ablation targets avoids lengthy electrical mapping and could improve the accuracy and efficacy of targeted AF ablation in patients while eliminating the need for repeat procedures.

Focal impulse and rotor mapping (FIRM) involves intracardiac detection and catheter ablation of re-entrant drivers (RDs), some of which may contribute to arrhythmia perpetuation in persistent atrial fibrillation (PsAF). Patient-specific computational models derived from late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) has the potential to non-invasively identify all areas of the fibrotic substrate where RDs could potentially be sustained, including locations where RDs may not manifest during mapped AF episodes. The objective of this study was to carry out multi-modal assessment of the arrhythmogenic propensity of the fibrotic substrate in PsAF patients by comparing locations of RD-harboring regions found in simulations and detected by FIRM (RDsim and RDFIRM) and analyze implications for ablation strategies predicated on targeting RDs. For 11 PsAF patients who underwent pre-procedure LGE-MRI and FIRM-guided ablation, we retrospectively simulated AF in individualized atrial models, with geometry and fibrosis distribution reconstructed from pre-ablation LGE-MRI scans, and identified RDsim sites. Regions harboring RDsim and RDFIRM were compared. RDsim were found in 38 atrial regions (median [inter-quartile range (IQR)] = 4 [3; 4] per model). RDFIRM were identified and subsequently ablated in 24 atrial regions (2 [1; 3] per patient), which was significantly fewer than the number of RDsim-harboring regions in corresponding models (p < 0.05). Computational modeling predicted RDsim in 20 of 24 (83%) atrial regions identified as RDFIRM-harboring during clinical mapping. In a large number of cases, we uncovered RDsim-harboring regions in which RDFIRM were never observed (18/22 regions that differed between the two modalities; 82%); we termed such cases “latent” RDsim sites. During follow-up (230 [180; 326] days), AF recurrence occurred in 7/11 (64%) individuals. Interestingly, latent RDsim sites were observed in all seven computational models corresponding to patients who experienced recurrent AF (2 [2; 2] per patient); in contrast, latent RDsim sites were only discovered in two of four patients who were free from AF during follow-up (0.5 [0; 1.5] per patient; p < 0.05 vs. patients with AF recurrence). We conclude that substrate-based ablation based on computational modeling could improve outcomes.

AIMS: The optimal site for biventricular endocardial (BIV(ENDO)) pacing remains undefined. Acute haemodynamic response (AHR) is reproducible marker of left ventricular (LV) contractility, best expressed as the change in the maximum rate of LV pressure (LV-dp/dt(max)), from a baseline state. We examined the relationship between factors known to impact LV contractility, whilst delivering BIV(ENDO) pacing at a variety of LV endocardial (LV(ENDO)) locations. METHODS AND RESULTS: We compiled a registry of acute LV(ENDO) pacing studies from five international centres: Johns Hopkins-USA, Bordeaux-France, Eindhoven-The Netherlands, Oxford-United Kingdom, and Guys and St Thomas’ NHS Foundation Trust, London-UK. In all, 104 patients incorporating 687 endocardial and 93 epicardial pacing locations were studied. Mean age was 66 ± 11 years, mean left ventricular ejection fraction 24.6 ± 7.7% and mean QRS duration of 163 ± 30 ms. In all, 50% were ischaemic [ischaemic cardiomyopathy (ICM)]. Scarred segments were associated with worse haemodynamics (dp/dt(max); 890 mmHg/s vs. 982 mmHg/s, P 50%) achieved greater increases in AHR than non-late activating tissue (LVLED 50%) yields greater improvements in AHR however, the optimal location is frequently not the site of latest activation.

We thank Penela et al for their comments and congratulate them for their achievements and unique work in the field. Starting in 2005, our group, as well as others, described the utility of cardiac magnetic resonance for ventricular tachycardia substrate identification in the setting of structural heart disease,1 …

Bipolar voltage mapping, as part of atrial fibrillation (AF) ablation, is traditionally performed in a point-by-point (PBP) approach using single-tip ablation catheters. Alternative techniques for fibrosis-delineation include fast-anatomical mapping (FAM) with multi-electrode circular catheters, and late gadolinium-enhanced magnetic-resonance imaging (LGE-MRI). The correlation between PBP, FAM, and LGE-MRI fibrosis assessment is unknown.In this study, we examined AF substrate using different modalities (PBP, FAM, and LGE-MRI mapping) in patients presenting for an AF ablation.LGE-MRI was performed pre-ablation in 26 patients (73% males, age 63±8years). Local image-intensity ratio (IIR) was used to normalize myocardial intensities. PBP- and FAM-voltage maps were acquired, in sinus rhythm, prior to ablation and co-registered to LGE-MRI.Mean bipolar voltage for all 19,087 FAM voltage points was 0.88±1.27mV and average IIR was 1.08±0.18. In an adjusted mixed-effects model, each unit increase in local IIR was associated with 57% decrease in bipolar voltage (p0.0001). IIR of0.74 corresponded to bipolar voltage0.5 mV. A total of 1554 PBP-mapping points were matched to the nearest FAM-point. In an adjusted mixed-effects model, log-FAM bipolar voltage was significantly associated with log-PBP bipolar voltage (ß=0.36, p0.0001). At low-voltages, FAM-mapping distribution was shifted to the left compared to PBP-mapping; at intermediate voltages, FAM and PBP voltages were overlapping; and at high voltages, FAM exceeded PBP-voltages.LGE-MRI, FAM and PBP-mapping show good correlation in delineating electro-anatomical AF substrate. Each approach has fundamental technical characteristics, the awareness of which allows proper assessment of atrial fibrosis.

The aim of the current investigation is to examine whether use of high-frequency jet ventilation (HFJV) during pulmonary vein isolation (PVI) performed with force-sensing catheters is associated with improved outcomes.Catheter ablation is well established as therapy for symptomatic atrial fibrillation (AF). Reconnection following PVI is commonly observed during repeat ablation procedures. Technologies that may optimize catheter stability and lesion delivery include both force-sensing ablation catheters and HFJV.Patients undergoing PVI at Johns Hopkins Hospital were prospectively enrolled in a registry. The study compared procedural characteristics, adverse event rates, and 1-year procedural outcomes in patients undergoing PVI supported either by standard ventilation or HFJV. Patient and procedural aspects were otherwise constant.Eighty-four HFJV patients and 84 matched control patients with 1-year outcome data were identified. Atrial arrhythmia recurrence occurred in 26 of 84 HFJV patients (31%) and 42 of 84 control patients (50%; p = 0.019). In patients with paroxysmal AF, arrhythmia recurrence in HFJV and control patients was 27.3% and 47.3%, respectively (p = 0.045). In patients with persistent AF, arrhythmia recurrence rates were not significantly different (37.9% in HFJV patients, 55.2% in control patients; p = 0.184). On multivariate analysis, HFJV was independently associated with improved freedom from arrhythmia recurrence. Vasopressor use during HFJV cases was significantly higher than during standard ventilation (79.7% vs. 22.4%; p = 0.001). Indices of catheter stability and contact force adequacy were significantly higher in the HFJV patients than in control patients. Complication rates in the 2 groups were similarly low.Use of HFJV in patients undergoing PVI with radiofrequency force-sensing catheters is associated with improved outcomes, without appreciable increase in adverse procedural events.