Search

Aims: (1) Quantitatively characterize the Pseudo Fibrosis Burden (PFB) of Left Atrial Appendage (LAA) Trabecular Musculi Pectinati (TMP) in patients with atrial fibrillation based on histological analysis; (2) Explore the passive dynamic properties of LAA TMP based on uniaxial tensile experiments and determine the hyperelastic constitutive parameters; (3) Explore samples Effects of different storage conditions on the mechanical properties of left atrial appendage TMP. Methods: Fifty TMP were isolated from the resected LAAs of 21 patients with atrial fibrillation and stored (23 strips in the -78°C cryopreservation group and 27 strips in the 4°C normal temperature storage group). The TMP stress-strain curve was obtained through uniaxial tension. According to this curve, the elastic modulus of the low strain zone (EMLS) and the high strain zone (EMHS) were respectively defined. The correlation between the TMP’s diameter and its mechanical properties and the impact of storage temperature on TMP mechanics were analyzed. Four strain energy functions were used to fit the TMP stress-strain curve to obtain the hyperelastic model constitutive parameters. Histological analysis of the axial and transverse microstructure of TMP was performed using Verhoeff-Van Gieson double staining method of Elastic fibers and collagen fibers (EVG) and Masson staining respectively, and the Pseudo Fiber Burden (PFB) was calculated. Analyze the correlation between mechanical properties and PFB. Results: Cryopreservation reduced the elastic modulus in the hyperelastic stage of TMP mechanical properties. EMLS (r=-0.7228, P

Background: The P-wave terminal force in lead V1 (PTFV1) is a marker of cardiomyopathy and risk of atrial fibrillation (AF). Low-voltage area (LVA) in the left atrium (LA), which indicates underlying atrial fibrosis, could predict AF recurrence. This study aimed to investigate the correlation between PTFV1 and LVA in older patients with paroxysmal AF. Methods: From May 1, 2020, to October 31, 2021, a total of 162 patients aged 65–80 years with paroxysmal AF who underwent index ablation procedures were enrolled. PTFV1 was measured in sinus rhythm (SR) using 12-lead electrocardiograms prior to the ablation. Abnormal PTFV1 was defined as a ≥ 4 mVms depression. Additional LVA ablation beyond circumferential pulmonary vein isolation (CPVI) was performed if LVAs were found. Results: Among the 162 patients, 88 had a normal PTFV1 and 74 had an abnormal PTFV1 prior to ablation. There was a significant difference in LVA in patients with and without an abnormal PTFV1 (LVA, 11.0 vs. 5.1 cm2, P < 0.001; LVA burden, 8.9% vs. 4.5%, P < 0.001). PTFV1 and PTAV1 were highest in the upper tertile with extensive LVAs (P < 0.001). Multivariate analysis revealed that abnormal PTFV1 was an independent predictor of LVAs (β = 4.961; 95% CI, 2.135–7.788; P < 0.001). After a median follow-up of 23 months, the AF-free survival rate was similar between the normal PTFV1 group and the abnormal PTFV1 group (13/88 vs. 12/74, hazard ratio [HR], 0.933 [95% CI, 0.425–2.047]; P = 0.861). Conclusions: Abnormal PTFV1 at baseline was independently associated with the extent of LVA in older patients with paroxysmal AF. [ABSTRACT FROM AUTHOR]

Introduction: Endovascular left atrial appendage occlusion (LAAO) is associated with a high incidence of peri-procedure silent cerebral embolism (SCE), while the recommended activated clotting time (ACT) level by the expert consensus is lower than that in atrial fibrillation (AF) ablation. The aim of our study was to investigate whether raising the targeted ACT level during LAAO to the same level as AF ablation could decrease the incidence of SCE. Methods: It was a prospective observational cohort study. Consecutive AF patients receiving LAAO between January 2021 and December 2022 were included and categorized into two groups based on the time of enrollment. Patients enrolled in 2021 (group 250) maintained a target ACT level of ≥250 s during LAAO procedure, while patients enrolled in 2022 (group 300) maintained the peri-procedure ACT ≥300 s. All patients underwent cerebral magnetic resonance imaging before and after the procedure. Results: A total of 81 patients were included (38 in the group 250 and 43 in the group 300). After inverse probability of treatment weighting (IPTW), patients in the group 250 showed a significantly lower incidence of SCE than group 300 (IPTW p = 0.038). Only a stable high ACT pattern could decrease the risk of SCE. No significant differences were found between other ACT change patterns on the SCE incidence. Conclusion: Raising the peri-procedure ACT level to a stable 300 s could decrease the risk of the SCE without increasing the major bleeding events. [ABSTRACT FROM AUTHOR]

Pre-harvest bagging can improve fruit color and protects against diseases. However, it was discovered that improper bagging times could lead to peel browning in production. Using the Ruixue apple variety as the research model, a study was conducted to compare the external and internal quality of fruits bagged at seven different timings between 50 and 115 days after full bloom (DAFB). Our findings indicate that delaying the bagging time can reduce the occurrence of peel browning in Ruixue apples. Compared to the control, the special bag reduced the browning index by 22.95%. However, the fruit point index of Ruixue fruits increased by 65.05% at 115 DAFB compared to 50 DAFB when bagging was delayed. The chlorophyll content of Ruixue fruits in special bags generally increased and then decreased, with the highest chlorophyll content of Ruixue fruits in special bags at 90 DAFB, which was 26.02 mg·kg−1. When the bagging process was delayed, the soluble solids, total phenols, and flavonoids content in the fruits increased, while the number of control volatiles decreased by 10. After two years of testing, results show that using special fruit bags at 90 DAFB bagging can significantly improve the fruit quality of Ruixue apple. [ABSTRACT FROM AUTHOR]

Background: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. General anesthesia (GA) resolves the problem of pain intolerability and provides regular respiratory mode which might improve the catheter maneuverability of AF ablation. This study aims to compare the procedural performance of PVI under GA versus conscious sedation (CS) from multiple perspectives. Methods: A total of 36 consecutive patients undergoing first AF ablation under GA were enrolled in GA group. Another 109 patients receiving AF ablation under CS in the same period were selected as the control group. After propensity score matching, 29 matched pairs with similar baseline characteristics were available for further analysis. The AIFV (using AI to analyze the raw data from CARTO3 system) system was used to evaluate six procedural parameters in each PVI procedure. Results: Compared with CS, PVI under GA had a significantly shorter total PVI time (51.4 min vs. 67.8 min; p =.003) and higher radiofrequency ratio (62.6% vs. 55.8%; p =.032). The number of gaps (1.0 vs. 3.0; p <.001) and the rate of break point were significantly lower in the GA group. GA was also associated with a higher effective ablation‐index ratio (87.5% vs. 74.1%; p <.001) and effective force‐over‐time ratio (85.3% vs. 69.2%; p =.001). After a medium follow‐up time of 24 months, 12/29 (41.4%) patients in the CS group and 6/29 (20.7%) patients in the GA group suffered from AF recurrence (p =.156). Conclusions: GA improves the lesion quality and procedural efficiency of PVI from multiple perspectives evaluated by the AIFV system. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation is an established therapeutic strategy to treat scar‐related macroreentry atrial tachycardia (MAT). However, the scar properties and arrhythmogenicity and the reentry type have not been clearly defined. Methods and Results: A total of 122 patients with scar‐related MAT were enrolled in this study. The atrial scars were classified into two categories: spontaneous scars (Group A: n = 28) and iatrogenic scars (Group B: n = 94). According to the relationship between scar location and the reentry circuit, MAT was described as scar pro‐flutter MAT, scar‐dependent MAT, and scar‐mediated MAT. The reentry type of MAT was significantly different between Groups A and B: pro‐flutter (40.5% vs. 62.0%, p = 0.02), scar‐dependent AT (40.5% vs. 13.0%, p < 0.001), and scar‐mediated AT (19.0% vs. 25.0%, p = 0.42). After a median follow‐up of 25 months, 21 patients with AT recurrence were observed. Compared with the spontaneous group, there was a lower recurrence rate of MAT in the iatrogenic group (28.6% vs. 10.6%, p = 0.03). Conclusion: Scar‐related MAT has three reentry types, and the proportion of each type varies with the scar properties and its arrhythmogenic basis. Optimization of the ablation strategy based on the scar properties to improve the long‐term outcome of catheter ablation of MAT is necessary. [ABSTRACT FROM AUTHOR]

Background Atrial tachycardias (ATs) frequently develop after a surgical Maze procedure. We aimed to elucidate the electrophysiologic mechanisms and their arrhythmogenic substrates of these ATs. Methods and results We retrospectively reviewed 20 patients (14 females, mean age of 55.5 ± 8.6 years) with post-Maze ATs who underwent high-resolution mapping at three institutions. The slow conduction areas, reentry circuits, voltage signals, complex electrograms, and their correlation with the surgical incisions and lesions placed in the surgical Maze procedures were analyzed. Thirty-six ATs with a mean cycle length of 260.0 ± 67.6 ms were mapped in these patients. Among them, 22 (61.1%) were anatomical macro-reentrant ATs (AMAT), 12 (33.3%) non-AMATs (localized ATs), and 2 (5.6%) focal ATs, respectively. Epicardial conduction bridges were observed in 6/20 (30.0%) patients and 7/36 (19.4%) ATs. Different arrhythmogenic substrates were identified in these ATs, including slow conduction regions within the previous lesion areas or between the incisions and anatomical structures, the prolonged activation pathways caused by the short lesions connecting the tricuspid annulus, and the circuits around the long incisions and/or lesions. Conclusions Reentry is the main mechanism of the post-Maze ATs. The pro-arrhythmic substrates are most likely caused by surgical incisions and lesions. The slow conduction regions and the protected channels yielded from these areas are the major arrhythmogenic factors. [ABSTRACT FROM AUTHOR]

To assess the prevalence and management of atrial thrombus in patients with nonvalvular atrial fibrillation (NVAF) and identify the risk factors of the nonresolution of atrial thrombus. This single-center retrospective observational study consecutively enrolled patients with NVAF and atrial thrombus detected using transesophageal echocardiography (TEE) or cardiac computed tomography angiography (CTA) from January 2012 to December 2020. Patients with prior left atrial appendage (LAA) intervention were excluded. The primary endpoint was the presence of atrial thrombus, while the secondary endpoint was the complete resolution of atrial thrombus. The prevalence of atrial thrombus in patients with NVAF was 1.4%. Ninety patients with atrial thrombus (mean age 62.8 ± 1 1.9 years and 61.1% men) were finally analyzed. Atrial thrombus was in the LAA in 82 (91.1%) patients. During follow up, 60% of the patients showed complete resolution of atrial thrombus. Congestive heart failure (odds ratio [OR]: 8.94; 95% confidence interval [CI]: 1.67-47.80) and a history of ischemic stroke (OR: 8.28; 95% CI: 1.48-46.42) were independently associated with the risk of the nonresolution of atrial thrombus. The presence of atrial thrombus in patients with NVAF who received anticoagulation therapy is non-negligible. Even in anticoagulated patients, TEE or cardiac CTA might still be needed. Congestive heart failure and a history of ischemic stroke are risk factors of the nonresolution of atrial thrombus. [ABSTRACT FROM AUTHOR]