Catheter ablation versus medical therapy for atrial fibrillation with prior stroke history: a prospective propensity score-matched cohort study.

BACKGROUND: Patients with atrial fibrillation (AF) and prior stroke history have a high risk of cardiovascular events despite anticoagulation therapy. It is unclear whether catheter ablation (CA) has further benefits in these patients. METHODS: AF patients with a previous history of stroke or systemic embolism (SE) from the prospective Chinese Atrial Fibrillation Registry study between August 2011 and December 2020 were included in the analysis. Patients were matched in a 1:1 ratio to CA or medical treatment (MT) based on propensity score. The primary outcome was a composite of all-cause death or ischemic stroke (IS)/SE. RESULTS: During a total of 4.1 ± 2.3 years of follow-up, the primary outcome occurred in 111 patients in the CA group (3.3 per 100 person-years) and in 229 patients in the MT group (5.7 per 100 person-years). The CA group had a lower risk of the primary outcome compared to the MT group [hazard ratio (HR) = 0.59, 95% CI: 0.47-0.74, P < 0.001]. There was a significant decreasing risk of all-cause mortality (HR = 0.43, 95% CI: 0.31-0.61, P < 0.001), IS/SE (HR = 0.73, 95% CI: 0.54-0.97, P = 0.033), cardiovascular mortality (HR = 0.32, 95% CI: 0.19-0.54, P < 0.001) and AF recurrence (HR = 0.33, 95% CI: 0.30-0.37, P < 0.001) in the CA group compared to that in the MT group. Sensitivity analysis generated consistent results when adjusting for time-dependent usage of anticoagulants. CONCLUSIONS: In AF patients with a prior stroke history, CA was associated with a lower combined risk of all-cause death or IS/SE. Further clinical trials are warranted to confirm the benefits of CA in these patients.

Catheter ablation of atrial fibrillation in patients with autoimmune disease: A propensity score matching study based on the China Atrial Fibrillation Registry.

BACKGROUND: Evidence on outcomes of catheter ablation (CA) for atrial fibrillation (AF) in patients with autoimmune disease (AD) is limited. HYPOTHESIS: Patients with AD had worse outcomes after CA procedures for AF. METHODS: A retrospective analysis was performed in patients undergoing AF ablation between 2012 and 2021. The risk of recurrence after ablation was investigated in patients with AD and a 1:4 propensity score matched non-AD group. RESULTS: We identified 107 patients with AD (64 ± 10 years, female 48.6%) who were matched with 428 non-AD patients (65 ± 10 years, female 43.9%). Patients with AD exhibited more severe AF-related symptoms. During the index procedure, a higher proportion of AD patients received nonpulmonary vein trigger ablation (18.7% vs. 8.4%, p = 0.002). Over a median follow-up of 36.3 months, patients with AD experienced a similar risk of recurrence with the non-AD group (41.1% vs. 36.2%, p = 0.21, hazard ratio [HR]: 1.23, 95% confidence interval [CI]: 0.86-1.76) despite a higher incidence of early recurrences (36.4% vs. 13.5%, p = 0.001). Compared with non-AD patients, patients with connective tissue disease were at an increased risk of recurrence (46.3% vs. 36.2%, p = 0.049, HR: 1.43, 95% CI: 1.00-2.05). Multivariate Cox regression analysis showed that the duration of AF history and corticosteroid therapy were independent predictors of postablation recurrence in patients with AD. CONCLUSIONS: In patients with AD, the risk of recurrence after ablation for AF during the follow-up was comparable with non-AD patients, but a higher risk of early recurrence was observed. Further research into the impact of AD on AF treatment is warranted.

Vein of Marshall ethanol infusion: First-step or adjunctive choice for perimitral atrial tachycardia?

BACKGROUND: Perimitral atrial tachycardia (PMAT) is the most frequent type of iatrogenic atrial tachycardia (AT) after atrial fibrillation (AF) ablation. Vein of Marshall ethanol infusion (EIVOM) is a promising technique in mitral isthmus (MI) ablation. METHODS: A total of 165 patients with PMAT were divided into three groups according to ablation strategies, including RF only group (n = 89), RF-EIVOM group (initial RF ablation with adjunctive EIVOM, n = 28), and EIVOM-RF group (first-step EIVOM with touch-up RF ablation, n = 48). Acute and follow-up procedure outcomes were evaluated. RESULTS: PMAT terminated in 89.9%, 89.3%, and 93.7% of patients in RF only, RF-EIVOM and EIVOM-RF groups, respectively (p = .715), with complete MI block achieved in 80.9%, 89.3%, and 95.8% of patients (EIVOM-RF vs. RF only, p = .012). First-step utilization of EIVOM was associated with a significant shortening of RF ablation time at MI (EIVOM-RF 2.1 ± 1.3 min, RF only 7.9 ± 5.9 min, RF-EIVOM 6.8 ± 5.8 min; p < .001) and a decrease in the proportion of patients need ablation within coronary sinus (CS, EIVOM-RF 14.6%, RF only 61.8%, RF-EIVOM 64.3%; p < .001). After a mean follow-up of 12.1 ± 6.2 months, AF/AT recurred in 39 (43.8%), 6 (21.4%), and 12 (25.0%) patients in RF only, RF-EIVOM, and EIVOM-RF group (RF-EIVOM vs. RF only, p = .026; EIVOM-RF vs. RF only, p = .022). CONCLUSIONS: EIVOM was associated with an enhanced acute MI block rate as well as reduced AF/AT recurrence. First-step utilization of EIVOM promises to significantly simplify the RF ablation process. CONDENSED ABSTRACT: PMAT is the most common type of iatrogenic AT after AF ablation procedures. EIVOM contributed to a higher acute MI block rate and lower arrhythmia recurrence risk during follow-up. First-step utilization of EIVOM significantly reduced the need for radiofrequency ablation at MI and inside CS with the advantage of creating a homogenous, transmural lesion and eliminating epicardial connections.

Decreased cellulose-degrading enzyme activity causes pod hardening of okra (Abelmoschus esculentus L. Moench).

Okra (Abelmoschus esculentus L. Moench) is an important tropical and subtropical crop species, but okra pods age rapidly after they meet harvest standards. The underlying mechanisms by which okra pods harden are unclear. In this study, we determined the cellulose and lignin contents of 'Chaowuxing' okra pods from 4 to 14 days postanthesis (DPA). Based on the histochemical staining of okra fruit during the active period of cellulose accumulation, we found that the hardening of okra fruit is due to the rapid accumulation of cellulose in the cell walls of vascular cells in the pulp. We used RNA-sequencing (RNA-Seq) analyses to investigate the genes that regulate okra fruit aging. Transcriptome sequencing data showed that after 7 DPA, expression of the cellulose synthase gene (CesA) decreased with time. In addition, expression of the gene encoding the first functional enzyme involved in cellulose hydrolysis (endoglucanase) also decreased, but its rate of decrease was much faster than that of the CesA. The quantitative real-time PCR (qRT-PCR) results were consistent with the RNA-Seq data. Accordingly, we speculate that the accumulation of cellulose during okra pod hardening occurs via a reduction in cellulose hydrolysis activity. The above results suggest that thickening of the cell wall caused by a significant increase in cellulose content in the vascular bundles causes okra hardening. The accumulation of cellulose is not directly achieved via increased expression of CesA but rather indirectly via decreased hydrolysis of cellulose.

Role of the notched unipolar electrogram in guiding catheter ablation of frequent premature ventricular contractions originating from the ventricular outflow tract.

OBJECTIVE: To investigate the value of a notched unipolar electrogram (N-uniEGM) in confirming the origin of premature ventricular contractions originating from the ventricular outflow tract (VOT-PVC) during mapping and ablation procedures. METHODS: This retrospective study enrolled consecutive patients with symptomatic idiopathic frequent VOT-PVCs that underwent radiofrequency ablation. The characteristics of the uniEGM of the successful ablation targets were analysed. N-uniEGM was defined as the uniEGM presenting a QS morphology with ≥1 steep notches on the downstroke deflection. All patients were followed-up for 3 months post-ablation. RESULTS: The study enrolled 190 patients with a mean ± SD age of 49.0 ± 15.3 years. N-uniEGMs were recorded in 124 of 190 (65.3%) patients. The N-uniEGM distribution area was limited to a mean ± SD of 0.8 ± 0.4 cm2. N-uniEGM showed consistency with the outcomes of activation mapping and pace mapping. Patients with an N-uniEGM had an ablation success rate of 98.4% (122 of 124) and their ablation times were significantly shorter than those without an N-uniEGM (7.6 ± 3.8 s versus 15.8 ± 8.8 s, respectively). The sensitivity and specificity of N-uniEGM in predicting successful ablation of VOT-PVCs were 72.6% and 91.7%, respectively. CONCLUSION: N-uniEGM was a highly specific and moderately sensitive predictor of successful radiofrequency ablation in patients with VOT-PVCs.

Electrocardiographic morphology during left bundle branch area pacing: Characteristics, underlying mechanisms, and clinical implications.

AIMS: In this study, we investigated the characteristics and underlying mechanisms of the electrocardiographic (ECG) morphology during left bundle branch area pacing (LBBAP), which have not been systematically described. METHODS: Patients with indications for permanent cardiac pacing underwent LBBAP attempts. The ECGs of patients with confirmed left bundle branch (LBB) capture were compared with those of individuals with right bundle branch block (RBBB) on 12-lead ECG. Intracardiac electrograms recorded during implantation were analyzed in all patients who underwent pacing. RESULTS: LBBAP was successfully achieved in 87.5% (56/64) of patients. The QRS morphologies in lead V1 during LBBAP, which typically demonstrated Qr (60.7%), qR (19.6%), rSR' (7.1%), or QS (12.5%) patterns, differed from those of native RBBB, which featured rsR' (57.5%), M shape (23.7%), or monophasic R patterns (18.7%). The terminal R' wave duration in lead V1 was significantly shorter during LBBAP than during native RBBB (51 ± 12 ms vs 85 ± 19 ms, p < 0.001). LBB potentials were recorded in 66.1% (37/56) of the LBBAP patients. No significant differences in ECG characteristics were found between LBBAP with and without recorded LBB potentials. The presence of bundle branch block during LBBAP significantly prolonged QRS duration, R wave peak time, and terminal R' wave duration in lead V1 . CONCLUSION: LBBAP-ECG patterns are characterized by a shorter terminal R' wave duration in lead V1 compared with that of native RBBB configurations. Bundle branch conduction integrity has an impact on ECG characteristics during LBBAP.

EGF upregulates RFPL3 and hTERT via the MEK signaling pathway in non­small cell lung cancer cells.

Activation of the epidermal growth factor receptor (EGFR) during tumor development can trigger the MEK signaling pathway. In the present study, we investigated the MEK signaling pathway in non­small cell lung cancer (NSCLC) cells with respect to the effect of epidermal growth factor (EGF) on expression of Ret finger protein like 3 (RFPL3) and human telomerase reverse transcriptase (hTERT), and the effect of RFPL3 overexpression on other MEK signaling proteins. In vitro, A549 and H1299 cells were treated with different concentrations of EGF for 24 h or 48 h. Expression of RFPL3 and hTERT at the mRNA and protein levels was determined by real­time quantitative PCR (RT­qPCR) and western blot analysis; cell viability was detected by MTT assay, and apoptosis was assayed via flow cytometry. We also pretreated A549 and H1299 cells with EGFR tyrosine kinase inhibitors, AG1478 and erlotinib, and MEK­specific inhibitor (PD98059) in the presence of EGF. We used western blot analysis to assess the expression levels of RFPL3, hTERT and related MEK­pathway proteins in A549 and H1299 cells transfected with RFPL3­overexpression plasmids. EGF significantly upregulated RFPL3 and hTERT protein levels in the NSCLC cells. RFPL3 and hTERT proteins upregulation by EGF were attenuated by pretreatment with AG1478 and erlotinib. EGF promoted proliferation and inhibited apoptosis; PD98059 decreased RFPL3 and hTERT protein expression; and RFPL3 overexpression increased the expression of hTERT and related MEK­pathway proteins. EGF upregulated RFPL3 and hTERT protein expression in NSCLC cells via the MEK pathway, promoted cell proliferation and inhibited apoptosis. RFPL3 overexpression increased expression of hTERT and related MEK signaling proteins (Ras, Raf, ERK and p­ERK), which implies that RFPL3 is a potential therapeutic target for NSCLC.

Dependent mechanism of Chinese prepositions processing in the brain: evidence from event-related potentials.

OBJECTIVE: To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain. METHODS: We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and prepositions. RESULTS: Both verbs and prepositions elicited a negativity at the frontal site in 230-330 ms and 350-500 ms window. No difference was seen in 230-330 ms and 350-500 ms window; In difference waves, a negativity was elicited in the left and right hemisphere at about 270-400 ms and 470-600 ms window for both open and closed-class words. CONCLUSION: These may demonstrate that prepositions in modern Chinese are probably not a separate class from verbs and that N280 may be not a specific component for only prepositions (or closed-class words).