Atrial Wall Research Articles

Total resection via right mini-thoracotomy for left atrial myxoma in juvenile Carney complex: a case report

Abstract Background Carney complex is a rare syndrome characterized by skin pigmentation, endocrine disorders, and myxomas. It is particularly notorious for its tendency to exhibit aggressive cardiac myxomas. Herein, we present a case of a juvenile female patient diagnosed with Carney complex who underwent a right lateral mini-thoracotomy. Case presentation A 13-year-old girl presented with sudden-onset left hemiplegia and dysarthria. Magnetic resonance imaging revealed multiple areas of restricted diffusion. Echocardiography identified a tumor in the left atrium, suspected to be related to Carney complex based on her medical history and physical examination findings. Surgery was performed via right lateral mini-thoracotomy, which minimized the risk of embolism and ensured a cosmetically favorable outcome. The left atrial wall defect was repaired with autologous pericardium. At 3 years postoperatively, follow-up echocardiography indicated no tumor recurrence and normal cardiac function. Conclusions Ongoing follow-ups are essential due to the aggressive nature of the Carney complex and its high recurrence rates. Right lateral mini-thoracotomy offers the advantage of avoiding re-sternotomy and minimizing adhesion dissection, making it the optimal choice for this case.

Ablation outcome in elderly women with atrial fibrillation undergoing pulsed-field ablation for electrical isolation of pulmonary veins and left atrial posterior wall

Abstract Background Documented evidences indicate higher prevalence of non-paroxysmal atrial fibrillation (AF) as well as in elderly women but also demonstrate the need to go beyond the pulmonary veins (PV) when treating these patients. Objective We compared the ablation outcome in elderly women (>70 years) with that in men in the same age group as well as in younger women (≤70 years) undergoing pulsed-field ablation (PFA) for persistent AF (PerAF). Methods This multicenter study included consecutive PerAF patients undergoing PFA as their first procedure. Patients were divided into 3 groups: Group 1: women >70 years, Group 2: men ≥70 years and Group 3: women ≤70 years. All received PV isolation (PVI) and isolation of left atrial posterior wall (LAPWI). Concentric overlapping lesions were placed in the LAPW. Number of applications were determined on a case-by-case basis. Isolation was confirmed by electrograms recorded on the multispline catheter. In all patients, ICE and fluoroscopy were used to optimize contact between the PFA catheter and the targeted tissue. Arrhythmia-monitoring was performed for 1-year with periodic clinic visits, event recorders and 7-day Holter monitoring. Results A total of 229 patients (group 1: 73; group 2: 47 and group 3: 109) were included in this analysis. Baseline characteristics of the study population is presented in table 1. At 1-year follow-up, 15 (20.5%), 3 (6.38%) and 10 (9.17%) from group 1, 2 and 3 respectively, experienced arrhythmia recurrence off-antiarrhythmic drugs. Recurrence rate in group 1 was significantly higher than that in group 2 (p=0.034) and group 3 (p=0.029). Conclusion In women aged ≤70 years and in elderly men (>70 years), PVI plus isolation of LAPW using ICE-guided PFA was associated with significantly lower recurrence rate compared to that in the elderly women. Given the higher recurrence rate following PVI+LAPWI in the elderly females, the operators should consider addressing all other AF-initiating extra-PV triggers for better ablation-outcome in this subset of the AF population.

True-MAD and pseudo-MAD in consecutive patients undergoing cardiovascular magnetic resonance

Abstract Background Mitral annulus disjunction (MAD) is a controversial imaging entity with uncertain clinical significance, which has been either considered a pathological entity potentially related to mitral valve prolapse (MVP) and sudden cardiac death or, on the contrary, a benign finding in normal hearts. Cardiovascular magnetic resonance (CMR) is poised to be the ideal imaging modality to assess MAD. Recently, a distinction between pseudo-MAD, present only in systole and secondary to juxtaposition of the billowing posterior leaflet on the adjacent left atrial wall, and true-MAD, where the insertion of the posterior leaflet is clearly displaced on the atrial wall either in diastole or in systole, has been suggested. Purpose We aimed to investigate the prevalence of pseudo-MAD and true-MAD in consecutive patients undergoing clinically-referred CMR. Methods This was a single-center retrospective study including consecutive patients referred to CMR from September 2023 to November 2023. Patients with feasible MAD assessment were included. MAD was defined as a ≥1 mm displacement between the left atrial wall-mitral valve leaflet junction hinge and the top of the left ventricular wall, measured from cine-CMR images in the three long-axis views. Pseudo-MAD and true-MAD were defined according to the presence of MAD only in systole or both in systole and diastole, respectively. MVP was defined as a systolic displacement ≥2 mm of one or both mitral valve leaflets above the annulus in 3-chamber view. Results Two-hundred-ninety patients (mean age 57±18 years; 181 men, 62%) were included. MVP and MAD were respectively found in 24 (8%) and 145 (50%) patients, of which 98 (34%) with true-MAD and 47 (16%) with pseudo-MAD. In all measurements, systolic MAD (2.6±1.3 mm) resulted equal to or greater than diastolic MAD (2.2±1.1 mm). The most frequent MAD location was the inferior wall in the two-chamber view (42%), whereas the rarest one was the inferolateral wall in the three-chamber view (17%). In patients with MVP, the prevalence of MAD was higher when considering all long-axis views (22 patients, 92%), of which 50% presented with true-MAD and 50% with pseudo-MAD. The extent of pseudo-MAD and true-MAD were both greater in patients with MVP (4.2±1.5 mm and 3.0±1.6 mm, respectively) than in those without MVP (2.3±1.0 and 2.1±0.9 mm; p<0.001 and p=0.007, respectively) in all locations. At the level of the inferolateral wall, the prevalence of MAD was 71% vs. 12% (p<0.001) in patients with vs. without MVP. Conclusions The presence of true-MAD was a common imaging finding in consecutive patients undergoing CMR, thus not resulting in a distinctive abnormal feature related to MVP or sudden cardiac death. Patients with MVP showed higher prevalence and extent of true-MAD and pseudo-MAD in all locations, in line with greater degeneration of the mitral annulus. Larger studies are needed to identify potential malignant characteristics of MAD.True-MAD (A,B) and pseudo-MAD (C,D).

Unipolar electroanatomical mapping outperforms bipolar voltage in detecting LGE areas in the left atrium

Abstract Introduction In atrial fibrillation (AF) management, understanding left atrial substrate is crucial. While both electroanatomical mapping (EAM) and late gadolinium enhancement MRI (LGE MRI) are reliable methods in assessing atrial substrate and are associated with the ablation outcome, recent findings have highlighted significant discrepancies between bipolar low voltage areas (LVA) in EAM and LGE areas. Objective Explore the relationship between LGE areas and unipolar LVAs by utilizing multipolar high-density (HD) mapping. Methods Nineteen patients scheduled for AF ablation underwent pre-ablation LGE-MRI. Left atrial (LA) segmentation was conducted using a convolutional neural network, which subsequently generated a 3D mesh integrating the LGE data. HD-EAM was performed in sinus rhythm for each patient, capturing at least 4000 points. The EAM map and LGE MRI mesh were co-registered. LVA areas were defined using voltage cut-offs of 0.5 mV for bipolar and 2.5 mV for unipolar measurements. Correspondence between LGE areas and LVAs on the anterior and posterior LA wall was analyzed. Results Both bipolar and unipolar LVA demonstrated high precision in detecting LGE areas (100% and 88% respectively). However, unipolar LVA exhibited a remarkable accuracy of 81% for detecting LGE areas specifically, whereas bipolar LVA displayed a significantly lower accuracy of 28%. These findings were consistent across the different atrial walls. Conclusion Incorporating unipolar voltage data into electroanatomical mapping in the atrium may bridge the observed gap between LGE areas and bipolar LVAs. Our findings highlight the significance of unipolar voltage in evaluating the left atrial substrate, potentially offering a more comprehensive insight into the different layers of atrial walls, and opening the door for new approaches in AF therapy.

Long term follow up in pulmonary embolism: can right ventricular strain echocardiographic imaging contribute to refine risk stratification?

Abstract Background In pulmonary embolism (PE), the usual evaluation of early risk of death includes clinical, biological and two-dimensional right ventricular (RV) echocardiographic (TTE) parameters. Purpose We hypothesized that myocardial strain analysis could contribute to risk of death prediction at long term follow up. Methods We retrospectively analyzed 477 patients hospitalized for acute EP. Usual parameters used to define RV dysfunction were evaluated using TTE (RV dilatation, systolic pulmonary arterial pressure, TAPSE, S’, Fractionnal Area Change (FAC), end diastolic RV diameter and right atrial, RA, area). In addition, we evaluated, left ventricle (LV) longitudinal, left atrial (LA), RA and RV free wall strains. Patients without history of cancer (n=419) were analyzed on the primary outcome of death at long term follow up. Results Mean of age was 63.7 ± 17.2 years and 227 (47.6) patients were male. The main clinical and echocardiographic characteristics are displayed in the Table 1. During a mean follow-up was 45.0 ± 16.6 months, the primary outcome occurred in 56 patients. In multivariable analysis, systolic pulmonary arterial pressure, indexed right atrial and left atrial volumes, right ventricle free wall strain, right ventricle global longitudinal strain were the only predictors of death (Table 2). Conclusion Atrial volumes and RV strain appeared as strong predictors of death in PE at long term follow up. Right ventricle myocardial strain analysis should be evaluated in each patient hospitalized for PE.

Ablation outcome in patients with atrial fibrillation undergoing ICE-guided pulsed-field ablation

Abstract Background Prior experiences from preclinical studies indicate the critical need of catheter-tissue- contact for creation of consistent transmural lesions in pulsed-field ablation (PFA). Intracardiac echocardiography (ICE) not only provide real-time visualization of cardiac structures, but also ensure adequate contact with the tissue. Objective We evaluated ablation outcome and reconnection rate following ICE-guided PFA procedure in patients with atrial fibrillation (AF). Methods Consecutive patients receiving ICE-guided PFA procedure were included in this multi-center analysis. All patients received isolation of PVs (PVI). Additional ablation of left atrial posterior wall (LAPW) was decided based on operator’s discretion. Concentric overlapping lesions were placed in the LAPW. Number of applications were determined on a case-by-case basis. ICE and fluoroscopy were used to optimize contact between the PFA catheter and the targeted tissue. All procedures were performed under uninterrupted anticoagulation. Mapping was done before and after ablation to confirm electrical isolation. Arrhythmia-monitoring was done for 1-year with periodic clinic visits, event recorders and 7-day Holter monitoring. Results A total of 372 patients [age: 62.69 ± 10.41 years, male: 201 (71.3%), paroxysmal AF: 67 (18%)] were included in this analysis of which 48 (12.9%) underwent PVI-only and the remaining subjects received additional ablation of LAPW. Mean number of applications were 34.67 ± 8.88 and 73.65 ± 37.21 for PVI-only and PVI+LAPWI cohorts respectively (p<0.001). No major procedural complications such as esophageal injury, atrio-esophageal fistula, pericardial effusion requiring drainage or cerebrovascular accidents were reported. During 1-year follow-up, 38 (10.2%) patients underwent repeat procedure for recurrence. Reconnection of PV and LAPW were found in only 2 (5.2%) patients. In all 38 patients, new triggers initiating AF were detected to be originating from interatrial septum: 25 (65.8%), superior vena cava: 9 (23.7%), coronary sinus: 7 (18.4%) and left atrial appendage: 6 (15.8%). Conclusion ICE-guided PFA procedures are safe and produce durable lesions leading to very low reconnection rate. The recurrence was mostly due to new triggers initiating AF.

Blood pressure in the early 40s impacts left atrial function by speckle-tracking strain two decades later: data from the ACE 1950 Study

Abstract Background With higher age, the left atrial (LA) wall stiffens, giving rise to impaired reservoir function and a compensatory increase in contractile function. The exposure of systemic blood pressures (BP) through life on the left heart chambers may be an explanation, but long-term follow-up studies are lacking. LA phasic function can be quantified by echocardiographic speckle-tracking strain analysis and provide prognostic information in cardiovascular disease. Purpose To explore the impact of BP in the early 40s on LA function assessed by strain two decades later. Methods A total of 3,706 individuals born in 1950 and residing in Akershus County, Norway, were included in the Akershus Cardiac Examination (ACE) 1950 Study. Baseline examinations were conducted between 2012-2015 and included echocardiography. Of those with available echocardiographic LA strain analyses, 2,399 participants had demographic and clinical data available from the Age 40 Program, a cardiovascular health survey performed when the participants were 40 years old. We assessed the impact of BP at age 40 on LA strain two decades later. Differences in LA reservoir (LASr) and contractile strain (LASct) between systolic (<120, 120-140 and >140mmHg) and diastolic (<70, 70-90, and >90mmHg) BP groups were assessed by ANOVA. Linear regression analyses were performed using BPs as continuous variables. Results Mean age of the 2,399 participants was 40.1±0.3 years at the time of the Age 40 program, and 63.9±0.6 years at the time of the ACE 1950 baseline examination. At age 40, 20.8% of participants had BP ≥140/ ≥90mmHg or used antihypertensive medication. Mean LASr was 35.1±9.2%, while mean LASct was 17.7±5.6%. LASr did not differ significantly between groups of systolic or diastolic BP. LASct, however, showed a statistically significant increase from lower to higher groups of both systolic and diastolic BP (Figure). In linear regression analyses, no associations were found between BPs and LASr, but systolic and diastolic BPs were both significantly associated with LASct (Table). The associations between BPs and LASct remained significant after adjustment for sex, BMI, daily smoking, resting heart rate and hypertension at age 40 (Table). Conclusions Higher systolic and diastolic BP in the early forties were associated with increased LA contractile function two decades later, but no significant changes in LA reservoir function were detected. This indicates contractile function as an early marker of subtle LA dysfunction.Figure.Table.

Organization of atrial flutter during pulse field ablation for atrial fibrillation

Abstract Background Pulse Field Ablation (PFA) has been acknowledged as an effective and safe tool for ablation of Atrial Fibrillation (AF). It is known that during AF ablation, the arrhythmia may organize into atrial flutter. The left atrial posterior wall is identified as a critical source of non-Pulmonary Vein (PV) triggers that facilitate maintenance of atrial fibrillation. Objective The purpose of this study is to investigate the phenomenon of atrial flutter organization from AF during the application of PFA. Methods This prospective multicentric study encompasses 117 consecutive patients with persistent AF across American and European institutions, undergoing first time catheter ablation. All receive isolation of the Pulmonary Veins (PV) plus Posterior Wall (PW) isolation. The PW isolation procedure targeted the standard area between the PVs and extended to the area demarcated by the line connecting the inferior borders of the inferior PV-encircling lesions to the coronary sinus defined lower part of PW (Fig. 1). The study documented the specific locations where AF organized into atrial flutter with a stable cycle length during PFA. Results Organization of AF to atrial flutter during PFA was observed in 72 (61.5%) patients. Analysis of the organization of flutter revealed that in 41 (56.9%) of these cases, flutter began while ablating the lower part of the PW. Moreover, 9 (12.5%) initiated at one of the PVs, and 22 (30.5%) during the ablation of the posterior wall. Notably, the flutter was described as perimitral flutter in 33 (45.8%), as typical flutter in 24 (33.3%), and as roof-dependent flutter in 15 (20.8%) of cases. Conclusion The findings underscore that during PFA for AF, there is a pronounced tendency for the arrhythmia to organize into atrial flutter, particularly during the ablation of the lower posterior wall. Notably ablation in the left atrium organized AF in typical atrial flutter at a considerable rate.Ablation on lower part of PW

Role of inflammation and macrophages in the formation of the atrial cardiomyopathy associated with obesity

Abstract Introduction The atrial fibrillation (AF), the most frequent cardiac arrhythmia in clinical practice is often associated with an atrial cardiomyopathy (ACM) which is favoured by several clinical conditions including metabolic diseases such as obesity. Recently, the epicardial adipose tissue (EAT) has emerged as an important component of ACM notably in the context of metabolic diseases. Epicardial progenitor cells (EPC) are the main source of EAT. The replacement of EAT by fibrosis is arrhythmogenic and involved inflammation but not yet characterized. The hypothesis tested here is that macrophages are central players for both the recruitment of EPC and replacement of EAT by fibrosis. Purpose-Aims First to characterize subpopulation of macrophages involves in the progression of ACM. Second, to study how the inflammatory environment regulates EPC differentiation. Method A spatial gene expression was used to analyze human samples (n=4) (Agreement, CODECOH, Declaration or authorization of activities involving the preservation and preparation of human body parts for scientific purposes DC-2020-4183). A well-characterized mouse model of atrial cardiomyopathy associated with obesity induced by high fat diet (HFD) was used to characterize macrophages associated with progression of ACM by using immunolabeling together with single nuclei RNA sequencing approaches. ACM was characterized by using echocardiography and atrial burst pacing to evaluate determine AF vulnerability. Transgenic RGB-MAC mice with macrophages tagged with McApple-Csf1R and ECGFP-CX3CR1 or with a knock-out for CCR2 were used to follow infiltration of myeloid cells in the atrial at the different stages of the ACM. Bi-photon microscopy was used to visualize cell subpopulations in the distinct area of the atrial wall. In some experiments EPC and macrophages were cocultured with transwell. Results Macrophages were detected in subepicardium of human atrial samples in area of fibro-fatty infiltrates. After 2 months of HFD, monocytes were infiltrated atria and macrophages were overexpressed in atria from 1 to 4 months of HFD. Using Bi-photon microscopy it was possible to visualise resident ECGFP-CX3CR1+ macrophages at the contact of EAT whereas McApple-Csfr1r+ macrophages were at the junction with fibrosis (figure 1). Preliminary data generated by single nuclei RNA sequencing showed clusters of different subpopulations of macrophages at different time point of the ACM (figure 2). We will present results on the effects of suppression of the CCR2 subpopulation of macrophages on characteristics of the ACM. Conclusion Distinct populations of macrophages i.e resident and monocyte-derived macrophages, participate to the distinct stages of the ACM caused by obesity in mice.Myeloid cells infiltration in epicardiumCCR2+cells infiltration in EAT-fibrosis

Right atrio-ventricular strain as a predictor of death in left-sided heart failure

Abstract Background Right ventricular (RV) strain is an established outcome predictor in heart failure (HF). However, the role of right atrial (RA) strain in the setting of left-sided HF is incompletely understood. Purpose We sought to evaluate the RV, RA and combined right atrio-ventricular (RAV) strain using speckle-tracking echocardiography in a cohort of patients with left-sided HF and to assess their prognostic role. Methods 121 consecutive patients (mean age 59±14 years, 74% men) with HF with reduced ejection fraction (HFrEF) referred to our echocardiography department were prospectively enrolled. The main endpoint was all-cause death. RV strain was measured as the average longitudinal strain of the basal, mid, and apical segments of the RV free wall and was reported as a positive value, thus a lower RV strain reflecting a greater longitudinal dysfunction. RA strain was defined as the maximal longitudinal displacement of the atrial wall at end-systole, corresponding to atrial reservoir function. RAV strain was defined as the sum of RV strain and RA strain. Results During a median follow-up of 19±11 months, 26 patients (21%) died. Patients who reached the endpoint had lower left ventricular ejection fraction (LVEF) (21±7% vs. 26±7%, p=0.001), lower tricuspid annular plane systolic excursion (16±3 vs. 18±5, p=0.02) and lower RA strain (13± 10% vs. 18±11%, p=0.03). In univariable Cox regression, RV, RA and RAV strain were all predictors of death: HR=1.05 [95% CI, 1.00-1.11], p=0.045 for RV strain, HR=0.95 [95% CI, 0.91-0.99], p=0.02 for RA strain, HR=0.97 [95% CI, 0.94-0.99], p=0.01 for RAV strain. We constructed a multivariable model with well-established event predictors in HFrEF and one strain index at a time. After adjustment for LVEF, maximal left atrial volume, tricuspid regurgitation severity and pulmonary artery systolic pressure, only RAV strain remained an independent predictor of death (HR=0.97 [95% CI, 0.94-1.00], p=0.04), while RV strain and RA strain did not (p=0.07 for both). LVEF did not emerge as a predictor of death in multivariable regression (p=0.57). Conclusion In left-sided HF, RV and RA strain were predictors of death. Combining the longitudinal strain of both right heart chambers might improve risk stratification, since RAV strain remained the only independent predictor of adverse outcome after adjustment for confounders.

Interleukin-6 levels in atrium and onset of spontaneous atrial fibrillation: is there a causal relationship

Abstract Background Cumulative evidence suggests that atrial interleukin-6 (IL-6) may play a significant role in the development of spontaneous postoperative atrial fibrillation (sPOAF) in coronary artery bypass grafting (CABG) patients. Our previous studies found that the IL-6 produced by the atrium is positively related to the development of sPOAF. However, the causal relationship between IL-6 and sPOAF is not established. Purpose This study aims to explore the potential causality between atrial IL-6 and spontaneous AF(sAF), alongside assessing the impact of IL-6 on the electrophysiological properties of atrial myocytes (AM). Methods To determine the causal link between IL-6 and sAF, mice were randomly divided into eight groups: seven receiving injections of varying doses of recombinant IL-6 protein groups (15ng/kg to180ng/kg) into the left atrial wall, and one control group (vehicle). Mice were monitored for sAF for 7 days using implanted telemetry device. At 48 hrs post-injection, the left atrial appendages of another set of mice were collected for analyzing levels of IL-6, Myeloperoxidase (MPO), Transforming Growth Factor-β1 (TGF-β1), and Tumor Necrosis Factor-α (TNF-α). To assess the effect of IL-6 on the electrophysiological characteristics of AM, AMs were isolated from the hearts of 12-week-old mice and divided into experimental and control groups for electrophysiological testing. The experimental group was perfused with extracellular solutions containing 100 ng/mL of IL-6 while the control group was perfused with standard extracellular solutions. The measurements focused on action potential (AP), transient outward potassium current (Ito), and inward rectifier potassium current (Ik1) after a 30-minute perfusion. Results As depicted in Fig. 1A, a dose-response relationship between IL-6 levels and sAF occurrence was observed, with incidence increasing from 0% at 15 ng/kg to 75% at 180 ng/kg (χ²= 16.691, P = 0.005). The injection of IL-6 also induced the production of MPO, TGF-β1, and TNF-α with a dose-dependent effects (Fig. 2). In comparison to control, the AP duration at 90% (APD90) and APD50 of repolarization of atrial myocytes were significantly shortened in IL-6 group (Fig. 1B). For voltages from -10mV to +70mV, atrial myocytes in the IL-6 group showed significantly lower Ito current density than those in the control (Fig. 1C). No significant alterations were observed in the impact of IL-6 on Ik1 current density in atrial myocytes (Fig.1D). Conclusion To the best of our knowledge, this is the first study that experimentally tested the causal relation between IL-6 and sAF. The injection of IL-6 could cause the onset of sAF and produce MPO, TGF-β1, and TNF-α with a significant dose-dependent effect. The effect of IL-6 on inducing sAF might be through its effect on reducing APD and Ito current density in mouse atrial myocytes. This suggests that inhibition of atrial IL-6 might be a potential novel sPOAF prevention strategy.

Efficacy of the peak frequency map for left atrial posterior wall isolation.

Complete isolation of the left atrial posterior wall (LAPW) is challenging owing to overlapping epicardial conduction. Peak frequency (PF) is a novel parameter that focuses on near- and far-field electrogram components. In this study, we aimed to determine whether transmural block completion is related to the ablation site PF. We analyzed 44 consecutive patients undergoing initial LAPW isolation (LAPWI) between June 2023 and February 2024. Pre-LAPWI and PF maps were obtained using an HD-Grid catheter. In 17 of the 44 patients (Group-1), LAPWI was performed conventionally. In the remaining 27 patients (Group-2), PF-guided LAPWI was applied based on Group-1 results. In Group-1, the left atrial (LA) roof and floor line success rates were 58.8% and 76.5%, respectively. The average PF value in the roof lines of patients with a completed block line was significantly higher than that of the remaining patients (286.6 ± 29.3 Hz vs. 236.1 ± 40.9 Hz, p = .012), but the floor lines were similar. In Group-2, relatively high PF values were targeted to achieve complete block of the LA roof and floor lines, following the results obtained in Group-1. The LA roof line success rates (92.6% vs. 58.8%, p = .007), total number of radiofrequency (RF) applications (22.7 ± 5.6 vs. 27.6 ± 8.5, p = .03), and procedural time (32.6 ± 18.3 vs. 47.9 ± 25.6 min, p = .03) differed between Group-1 and Group-2. Using a PF map for determining the optimal ablation line for LAPWI by RF catheter ablation is feasible.

Comparative Effects of Different Power Settings for Achieving Transmural Isolation of the Left Atrial Posterior Wall with Radiofrequency Energy.

Comparative Effects of Different Power Settings for Achieving Transmural Isolation of the Left Atrial Posterior Wall with Radiofrequency Energy.

The spatial overlap between left atrial epicardial adipose tissue and fibrosis is not associated to clinical stage of atrial fibrillation

Left atrial (LA) epicardial adipose tissue (EAT) and wall fibrosis are both proven to contribute to the pathogenesis and progression of atrial fibrillation (AF). The theory of LA wall fibrosis induction by local EAT infiltration, paracrine secretions, and activation of the inflammatory process is strongly advocated, but the imaging evidence for anatomical proximity of the two tissue types and its association to AF stage is lacking. Accordingly, the aim of the study was to analyse the spatial overlap between LA EAT and adjacent wall fibrosis using 3D Dixon water-fat separated late gadolinium enhancement (LGE-Dixon) MRI and correlate the findings with the clinical AF stage. Forty-two AF patients (18 paroxysmal, 10 persistent, and 14 permanent) and nine non-AF patients were scanned. The permanent AF patients had greater LA volume and EAT than the paroxysmal group. The LA fibrosis area showed the same trend. The LA EAT-fibrosis overlap area was small and there was no significant difference between the three AF stages. There was no significant relationship between LA EAT- fibrosis overlap area and AF type. The findings shed light on the complex interplay between LA fibrosis and EAT during the progression from paroxysmal to permanent AF.

Donor Posterior Atrial Flap Rotation for Left Atrial Cuff Reconstruction in Lung Transplantation.

We describe in detail a novel surgical technique for repairing donor anterior left atrial wall defect in vivo by rotating the posterior atrial flap during lung transplantation. This method can safely and effectively address the most common type of donor left atrial cuff defect: the anterior wall defect, with the intact posterior wall, typically retained when the donor heart is also used. During atrial cuff anastomosis in lung transplantation, the excess donor posterior atrial wall is trimmed into an atrial flap. After the posterior wall anastomosis is completed, the atrial flap is rotated 180° and used as a patch for anterior wall reconstruction anastomosis. After restoring blood flow, the flow rate of the pulmonary vein is normal and smooth as confirmed by transesophageal echocardiography. Compared with the traditional patch reconstruction method, the new method effectively reduces the atrial cuff anastomosis time. Our results showed no significant difference in pulmonary vein obstruction after reconstruction. Pulmonary artery systolic blood pressure was significantly lower and pulmonary function improved postoperatively in all groups, with no significant differences among the groups. The new technique provides a feasible strategy for the reconstruction of left atrial cuff defects and can improve the effective utilization rate of donor lungs.

Outcomes of the Modified Warden Procedure for Partial Anomalous Pulmonary Venous Connection Drainage to a High Location in the Superior Vena Cava

To report the safety and effectiveness of a modified Warden procedure. Twenty-six (26) patients underwent modified Warden surgery at our centre from September 2017 to September 2021. In all patients, the superior vena cava (SVC) was reconstructed by turning the atrial wall in the main body of the right atrium upwards and applying fresh autologous pericardial patches. There were 13 male patients and 13 female patients, and the median age of the patients was 7.0 (range, 0.3-47.0) years. The median follow-up time after surgery was 47.0 (range, 32.0-80.0) months. The aortic cross-clamp time was 108.50±34.72 minutes, the cardiopulmonary bypass time was 154.81±41.65 minutes, the median postoperative mechanical ventilation time was 8.5 (range, 0.0-91.0) hours, the median intensive care unit stay was 43.5 (range, 15.0-352.0) hours, and the median length of postoperative hospital stay was 7.0 (range, 6.0-19.0) days. All patients were safely and successfully discharged from the hospital. No deaths or sinus node dysfunction occurred during the follow-up period. The mean gradient of the reconstructed SVC and/or the right pulmonary vein (PV) increased in eight patients and decreased to less than 1 mmHg in six patients. One (1) adult patient had already undergone two vascular interventions, and one child had persistent stenosis but did not undergo reoperation at the time of the study. In addition, two patients were subjected to pericardial windowing. A modified Warden technique using a right atrial flap and autologous pericardium effectively corrected the high-plane connection between the PVs and SVC. This technique effectively avoids sinus node dysfunction; however, a short-term increase in the differential pressure of the re-established SVC or PV after the procedure is acceptable, and reintervention is required only in rare cases.

Comparison of efficiency of PFA catheter designs by computer modeling.

Various catheter designs are appearing for Pulsed Field Ablation (PFA). It is unclear if they differ in terms of safety and efficiency. PFA studies have reported hemolysis, kidney injury, high troponin, among other side effects. Using a CT-derived computer model, we compared catheter designs using two metrics: (1) efficiency: power delivered to an atrial wall target, expressed as a percent of total generator power; and (2) safety: electric current to achieve 90% transmurality (since more energy causes more collateral effects), as well as the corresponding electrode current density (ECD), a heat and bubble metric. The following catheter designs were compared: penta-spline basket, Nitinol spheres (focal 9 mm and large 1-shot), circular, balloon, and flex-circuit. Target was a 6 × 47 mm circumferential segment of atrial wall at LPV antrum. Transmurality was defined as percent of target having >600 volts per centimeter (V/cm) electric field needed for electroporation. Efficiency was 0.9, 1.4, 2.7, 5.9, 10, and 12% for the large 1-shot and 9 mm Nitinol spheres, penta-spline, circular, flex spline, and balloon catheters, respectively. Regarding safety, currents for 90% transmurality were 70, 39,36,12.5, 5.3, and 4 Amps for the same respective catheters, with less being safer. ECD was 124, 25, 74, 83, 41, and 31 A/cm2, respectively. Computer models demonstrated a remarkable range in efficiency among catheters studied. Those having less atrial blood exposure had the highest efficiencies, with factors of up to 13X more efficiency compared to exposed ones. Higher efficiency designs have less collateral current and are safer. Confirmatory in-vivo studies are required.

Effect of Pulmonary Vein Isolation with Left Atrial Wall Isolation Plus Selective CFAE Ablation in Patients with Persistent Atrial Fibrillation.

Pulmonary vein isolation (PVI) is a foundational treatment for persistent atrial fibrillation (PeAF), but the effectiveness of adding posterior wall isolation (PWI) and selective complex fractionated atrial electrogram (CFAE) ablation in the roof and anterior wall remains debated. The potential of these additional ablation techniques to improve long-term outcomes for PeAF patients is still uncertain. This retrospective study included 151 PeAF patients who underwent first-time catheter ablation at our center. The choice of ablation strategy was based on the operator's clinical judgment, taking into account the patient's specific condition and anatomical features. Patients were divided into two groups: the PVI group, which received PVI alone, and the modified PWI (MPWI) group, which received PVI along with additional PWI and selective CFAEs ablation in the roof and anterior wall. The primary endpoint was the absence of atrial arrhythmia lasting more than 30 s, without antiarrhythmic drugs, at 12 months. At the 12-month follow-up, 77.3% of the patients in the MPWI group and 52.1% of the patients in the PVI group remained in sinus rhythm without an atrial arrhythmia recurrence (p = 0.001). The BIC-based Cox regression analysis identified the ablation strategy and atrial fibrillation (AF) duration as independent predictors of recurrence across the cohort. It was found that MPWI significantly reduced the risk of recurrence, while a longer AF duration increased it. In the MPWI group, AF duration, left ventricular internal diameter in systole (LVIDs), and moderate or greater tricuspid regurgitation were independent predictors of recurrence. In the PVI group, only the left atrial low voltage area (LVA) index was a significant predictor. The addition of PWI and selective CFAE ablation to PVI significantly improves 12-month arrhythmia-free survival compared to PVI alone, demonstrating the superiority of this combined approach in improving long-term outcomes for patients with persistent AF.

Outcomes of hybrid surgical ablation and concomitant left atrial appendage exclusion in long-standing persistent atrial fibrillation.

Management of patients with long-standing persistent atrial fibrillation (LSPAF) presents a clinical challenge. Hybrid convergent ablation has been shown to have superior efficacy compared to endocardial-only ablation. However, data on concomitant left atrial appendage (LAA) management along with hybrid ablation is sparse. We aimed to evaluate the effectiveness of concomitant hybrid convergent ablation and LAA clipping in patients with LSPAF. We conducted a retrospective analysis of all patients with LSPAF who underwent hybrid surgical ablation with LAA clipping at our institution. The primary endpoint was a recurrence of atrial arrhythmias at 12 months. Further, the durability of surgical left atrial posterior wall ablation was examined during the endocardial catheter ablation using standing electrophysiological criteria. A total of 79 patients were included. Mean age was 63.5 ± 9.6 years, and 71% were males. LAA clipping was performed in 99% of patients. The mean time between the surgical and endocardial stages of the procedure was 2.6 ± 1.7 months. Persistent posterior wall activity was observed in 34.2% (n = 27/79) patients during the endocardial phase of the procedure. Cardiac implantable electronic device was used in 74% of patients for monitoring of recurrence of atrial fibrillation (AF). The primary effectiveness of AF freedom at 12 months was 73.8% (45/61). Over a 12-month follow-up period, 11.4% (9/79) of patients required repeat catheter ablation, of which 88.9% (8/9) had evidence of persistent posterior wall activity. Concomitant hybrid convergent ablation and LAA exclusion with an atrial clip provides reasonable long-term AF-free survival in patients with LSPAF. Persistent posterior wall activity is seen commonly in patients presenting with recurrent AF following hybrid convergent AF ablation.

Numerical Study of the Effect of the Port Angle of the Superior Vena Cava Supplying Cannula on Hemodynamics in the Right Atrium in VV-ECMO.

Objective: To elucidate the pattern of the influence of the port angle of the superior vena cava supplying cannula (SVCS) on hemodynamics within the right atrium in VV-ECMO. Methods: A three-dimensional model of the right atrium was established based on CT images of a real patient. The 3D models of the SVCS and inferior vena cava draining cannula (IVCD) were established based on the Edwards 18Fr and Medos 22Fr real intubation models, respectively. Based on these models, three-dimensional models of the SVCS ports with bending angles of -90°, -60°, -30°, 0°, 30°, 60°, and 90° in the plane formed by the centerline of the SVCS and the center point of the tricuspid valve (TV) were established. Transient-state computational fluid dynamics (CFD) was performed to clarify the right atrium blood flow pattern and hemodynamic states at different SVCS port orientation angles. The velocity clouds, wall pressure, wall shear stress (WSS), relative residence time (RRT), and recirculation fraction (RF) were calculated to assess hemodynamic changes in the right atrium at different angles of the port of the SVCS. Results: As the angle of the port of the superior chamber cannula changed, the location of the high-velocity blood impingement from the SVCS changed, and the pattern of blood flow within the right atrium was dramatically altered. The results for the maximum right atrial wall pressure were 13,472 pa, 13,424 pa, 10,915 pa, 7680.2 pa, 5890.3 pa, 5597.6 pa, and 7883.5 pa (-90° vs. -60° vs. -30° vs. 0° vs. 30° vs. 60° vs. 90°), and the results for the mean right atrial wall pressure were 6788.9 pa, 8615.1 pa, 8684.9 pa, 6717.2 pa, 5429.2 pa, 5455.6 pa, and 7117.8 pa ( -90° vs. -60° vs. -30° vs. 0° vs. 30° vs. 60° vs. 90°). The results of the maximum right atrial wall WSS in the seven cases were 63.572 pa, 55.839 pa, 31.705 pa, 39.531 pa, 40.11 pa, 28.474 pa, and 35.424 (-90° vs. -60° vs. -30° vs. 0° vs. 30° vs. 60° vs. 90°), respectively, and the results of the mean right atrial wall WSS results were 3.8589 pa, 3.6706 pa, 3.3013 pa, 3.2487 pa, 2.3995 pa, 1.3304 pa, and 2.0747 pa (-90° vs. -60° vs. -30° vs. 0° vs. 30° vs. 60° vs. 90°), respectively. The results for the area percentage of high RRT in the seven cases were 3.44%, 2.23%, 4.24%, 1.83%, 3.69%, 7.73%, and 3.68% (-90° vs. -60° vs. -30° vs. 0° vs. 30° vs. 60° vs. 90°), and the results for the RF were 21.57%, 23.24%, 19.78%, 12.57%, 10.24%, 5.07%, and 8.05% (-90° vs. -60° vs. -30° vs. 0° vs. 30° vs. 60° vs. 90°). Conclusions: The more the port of the SVCS is oriented toward the TV, the more favorable it is for reducing RF and the impingement of blood flow in the right atrial wall, but there may be an increased risk of RRT. The opposite orientation of the SVCS port to the TV is not conducive to reducing flow impingement on the right atrial wall and RF.