A case report on the usefulness of combining online continuous wavelet transform analysis with a novel real-time phase mapping system during nonparoxysmal atrial fibrillation catheter ablation.
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ABSTRACT:
SUBMITTER: Yokoyama Y
PROVIDER: S-EPMC9039114 | biostudies-literature | 2022 Apr
REPOSITORIES: biostudies-literature
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A case report on the usefulness of combining online continuous wavelet transform analysis with a novel real-time phase mapping system during nonparoxysmal atrial fibrillation catheter ablation.
Yokoyama Yasuhiro Y Nakamura Hiroaki H Kato Nobutaka N Higuchi Koji K
HeartRhythm case reports 20220119 4
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Project description:BackgroundAtrial fibrosis is involved in non-paroxysmal atrial fibrillation (NPAF) and is mainly mediated by the calcium-binding protein S100A4. This study aimed to verify the role of circulating S100A4 in the diagnosis of atrial fibrosis and the prognosis of NPAF.MethodsConsecutive NPAF patients undergoing catheter ablation were selected. Patients with low voltage amplitudes (<0.40 mV) in the left atrium (LA), defined as low voltage zones (LVZs), were grouped in the scar group by electroanatomic mapping (EAM). Circulating S100A4 was detected by a human enzyme-linked immunosorbent assay (ELISA). The role of S100A4 in atrial fibrosis was further evaluated by Masson's trichrome staining and immunochemistry (IHC) in NPAF (atrial pacing) and control dogs. The prognostic value of the circulating S100A4 was evaluated by Cox regression analyses, the Kaplan-Meier (KM) method, and receiver operating characteristic (ROC) curves.ResultsWe enrolled a total of 101 NPAF patients (age 60±8 years) who underwent EAM, including 53 patients with scars and 48 patients without scars at 1-year follow-up. The scar group showed a higher serum level of S100A4 (3.4±1.7 vs. 2.5±1.4 ng/mL, P<0.001) than the non-scar group. In the canine model, scar size matched the larger location of interstitial fibrosis in the NPAF group determined by Masson's trichrome staining. The expression of α-SMA and S100A4 was elevated in the NPAF group as determined by IHC compared to the control group (P<0.001). The clinical recurrence rate was markedly elevated in the scar group (27.1% vs. 8.9%, P<0.001), and the area under the ROC curve was high (0.865, 95% CI: 0.750-0.981) in predicting clinical recurrence of NPAF with the circulating S100A4 model.ConclusionsCirculating S100A4 plays a role in atrial fibrosis in NPAF patients following ablation. The level of serum S100A4 can predict the clinical recurrence of NPAF.
| S-EPMC8506725 | biostudies-literature
Project description:Background and objectivesWe investigated whether extra-pulmonary vein (PV) ablation targeting a high maximal slope of the action potential duration restitution curve (Smax) improves the rhythm outcome of persistent atrial fibrillation (PeAF) ablation.MethodsIn this open-label, multi-center, randomized, and controlled trial, 178 PeAF patients were randomized with 1:1 ratio to computational modeling-guided virtual Smax ablation (V-Smax) or empirical ablation (E-ABL) groups. Smax maps were generated by computational modeling based on atrial substrate maps acquired during clinical procedures in sinus rhythm. Smax maps were generated during the clinical PV isolation (PVI). The V-Smax group underwent an additional extra-PV ablation after PVI targeting the virtual high Smax sites.ResultsAfter a mean follow-up period of 12.3±5.2 months, the clinical recurrence rates (25.6% vs. 23.9% in the V-Smax and the E-ABL group, p=0.880) or recurrence appearing as atrial tachycardia (11.1% vs. 5.7%, p=0.169) did not differ between the 2 groups. The post-ablation cardioversion rate was higher in the V-Smax group than E-ABL group (14.4% vs. 5.7%, p=0.027). Among antiarrhythmic drug-free patients (n=129), the AF freedom rate was 78.7% in the V-Smax group and 80.9% in the E-ABL group (p=0.776). The total procedure time was longer in the V-Smax group (p=0.008), but no significant difference was found in the major complication rates (p=0.497) between the groups.ConclusionsUnlike a dominant frequency ablation, the computational modeling-guided V-Smax ablation did not improve the rhythm outcome of the PeAF ablation and had a longer procedure time.Trial registrationClinicalTrials.gov Identifier: NCT02558699.
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Project description:Atrial fibrillation (AF) is associated with complex and multifaceted etiology including neural modulation that alters atrial electrophysiology. To explore potential biomarkers for AF and AF recurrence. Peripheral histidine levels in PeAF were significantly higher compared to those in the right atrium and coronary sinus. Receiver operating characteristic (ROC) analysis revealed that peripheral histidine was predictive of AF recurrence, with an optimal cutoff value of ≤ 4.71 µg/mL, yielding a sensitivity of 76.3% and a specificity of 76.5%. The area under the ROC curve (AUC) was 0.75 (95% CI, 0.59–0.90). Peripheral His was robustly associated with lower incidence of AF recurrence after covariates adjustment (OR 0.34, 95% CI 0.14- 0.71, p=0.01).
2025-02-14 | GSE289284 | GEO
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| S-EPMC11398660 | biostudies-literature
Project description:Yield is an important indicator in evaluating rice planting, and it is the collective result of various factors over multiple growth stages. To achieve a large-scale accurate prediction of rice yield, based on yield estimation models using a single growth stage and conventional spectral transformation methods, this study introduced the continuous wavelet transform algorithm and constructed models under the premise of combined multiple growth stages. In this study, canopy reflectance spectra at four important stages of rice elongation, heading, flowering and milky were selected, and then, a rice yield estimation model was constructed by combining vegetation index, first derivative and wavelet transform based on random forest algorithm or multiple stepwise regression. This study found that the combination of multiple growth stages significantly improved the model accuracy. In addition, after two validations, the optimal model combination for rice yield estimation is first derivative-wavelet transform-vegetation index-random forest model based on four growth stages, with the coefficient of determination (R2) of 0.86, the root mean square error (RMSE) of 35.50 g·m-2 and the mean absolute percentage error (MAPE) of 4.6% for the training set, R2 of 0.85, RMSE of 33.40 g.m-2 and MAPE 4.30% for the validation set 1, and R2 of 0.80, RMSE of 37.40 g·m-2 and MAPE of 4.60% for the validation set 2. The research results demonstrated that the established model could accurately predict rice yield, providing technical support and a foundation for large-scale statistical estimating of rice yield.
| S-EPMC9285008 | biostudies-literature
Project description:Mounting evidence for the role of sleep spindles in neuroplasticity has led to an increased interest in these non-rapid eye movement (NREM) sleep oscillations. It has been hypothesized that fast and slow spindles might play a different role in memory processing. Here, we present a new sleep spindle detection algorithm utilizing a continuous wavelet transform (CWT) and individual adjustment of slow and fast spindle frequency ranges. Eighteen nap recordings of ten subjects were used for algorithm validation. Our method was compared with both a human scorer and a commercially available SIESTA spindle detector. For the validation set, mean agreement between our detector and human scorer measured during sleep stage 2 using kappa coefficient was 0.45, whereas mean agreement between our detector and SIESTA algorithm was 0.62. Our algorithm was also applied to sleep-related memory consolidation data previously analyzed with a SIESTA detector and confirmed previous findings of significant correlation between spindle density and declarative memory consolidation. We then applied our method to a study in monozygotic (MZ) and dizygotic (DZ) twins, examining the genetic component of slow and fast sleep spindle parameters. Our analysis revealed strong genetic influence on variance of all slow spindle parameters, weaker genetic effect on fast spindles, and no effects on fast spindle density and number during stage 2 sleep.
| S-EPMC4652604 | biostudies-literature
Project description:BackgroundAdditional ablation strategies after pulmonary vein isolation (PVI) for patients with nonparoxysmal atrial fibrillation (non-PAF) lasting ≥2 years have not been fully effective. This is presumably because of insufficient identification of non-PAF maintenance mechanisms. In this study, we employed a novel online and real-time phase mapping system, ExTRa Mapping, to identify and modulate rotors as one of the non-PAF maintenance mechanisms in patients with non-PAF sustained after PVI. We investigated the relationship between outcomes of ExTRa Mapping-guided rotor ablation (ExTRa-ABL) and non-PAF duration prior to this procedure.MethodsThis study consisted of 73 non-PAF patients (63 ± 8 years, non-PAF duration 31 ± 37 months) who underwent the first ExTRa-ABL in patients with non-PAF sustained after completion of PVI.ResultsFreedom from non-PAF/atrial tachycardia (AT) recurrence at 12 months after ExTRa-ABL was achieved in 50 (69%) of patients. The non-PAF duration prior to ExTRa-ABL was significantly longer in patients with non-PAF/AT recurrence after ExTRa-ABL compared with those without (56 ± 50 vs. 19 ± 22 months, p = .001). In patients with non-PAF duration of ≤60 months prior to ExTRa-ABL, compared with >60 months, non-PAF/AT-free rate was significantly higher (68.9% vs. 23.1%, p < .001), during the follow-up of 36 ± 18 months.ConclusionsA non-PAF duration of ≤60 months prior to ExTRa-ABL was associated with a better outcome. The effect of ExTRa-ABL was considered to be limited in patients with >60 months of non-PAF duration.
| S-EPMC10407168 | biostudies-literature
Project description: Not available
| S-EPMC1860761 | biostudies-literature
Project description:BACKGROUND:Combined 'hybrid' thoracoscopic and percutaneous atrial fibrillation (AF) ablation is a strategy used to treat AF in patients with therapy-resistant symptomatic AF. We aimed to study efficacy and safety of single-stage hybrid AF ablation in patients with symptomatic persistent AF, or paroxysmal AF with failed endocardial ablation, and assess determinants of success and quality of life. METHODS:We included consecutive patients undergoing single-stage hybrid AF ablation. First, we performed epicardial ablation, via thoracoscopic access, to isolate the pulmonary veins and superior caval vein and to create a posterior left atrial box. Thereafter, isolation was assessed endocardially and complementary endocardial ablation was performed, followed by cavotricuspid isthmus ablation. Efficacy was assessed by 12-lead electrocardiography and 72-hour Holter monitoring after 3, 6 and 12 months. Recurrence was defined as AF/atrial flutter/tachycardia recorded by electrocardiography or Holter monitoring lasting >30 s during 1‑year follow-up. RESULTS:Fifty patients were included, 57 ± 9 years, 38 (76%) men, 5 (10%) paroxysmal, 34 (68%) persistent and 11 (22%) long-standing persistent AF. At 1‑year 38 (76%) maintained sinus rhythm off antiarrhythmic drugs. Majority of recurrences were atrial flutter (9/12 patients). Success was associated with type of AF (p = 0.039). Patients with paroxysmal AF had highest success, patients with longstanding persistent AF had lowest success. Seven (14%) patients had procedure-related complications. Quality of life improved after ablation in patients who maintained sinus rhythm. CONCLUSION:Success of single-stage hybrid AF ablation was 76% off antiarrhythmic drugs, being associated with type of AF. Quality of life improved significantly, Procedure-related complications occurred in 14%.
| S-EPMC6393682 | biostudies-literature
Project description:The dimension of the void area in pavement is crucial to its structural safety. However, there is no effective method to measure its geometric parameters. To address this issue, a void size extraction algorithm based on the continuous wavelet transform (CWT) method was proposed using ground-penetrating radar (GPR) signal. Firstly, the finite-difference time-domain (FDTD) method was used to investigate the GPR response of void areas with different shapes, sizes, and depths. Next, the GPR signal was processed using the CWT method, and a 3D image based on the CWT result was used to visualize the void area. Based on the differences between the void and normal pavement in the time and frequency domains, the signal with maximum energy from the CWT time-frequency result was extracted and combined to reconstruct the new B-scan image, where void areas have energy concentration phenomenon. Based on this, width and depth of void detection algorithm was proposed to recognize the void area. Finally, the detection algorithm was verified both in numerical model and physical lab model. The results indicated that the CWT time-frequency energy spectrum can be used to enhance the void feature, and the 3D CWT image can clearly visualize the void area with a highlighted energy area. After fully testing and validating in numerical and lab models, our proposed method achieved high accuracy in void width and depth detection, providing a precise method for estimating void dimension in pavement. This method can guide DOT departments to carry out pre-maintenance, thereby ensuring pavement safety.
| S-EPMC10641085 | biostudies-literature