scholarly journals The magnitude and the course of local impedance drop to guide successful AF ablation: insight from an Italian registry

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
V Schillaci ◽  
G Zucchelli ◽  
F Solimene ◽  
A De Simone ◽  
C Pandozi ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background It has been demonstrated that an ablation strategy based on local impedance (LI) algorithm is helpful in guiding successful ablation of atrial fibrillation (AF) cases. How the magnitude and the course of LI drop could impact the effectiveness of ablation has to be proved. Purpose We aimed to evaluate LI drop characteristics in predicting effective radiofrequency (RF) ablation of consecutive AF cases. Methods Consecutive patients undergoing AF ablation at 8 Italian centers were included in the CHARISMA registry. A RF ablation catheter equipped with mini-electrodes technology and a dedicated algorithm was used to measure LI and to guide ablation. For our purpose, we defined the time to drop (τ) as the time for the first deflection of LI drop to the plateau. RF applications were targeted to a LI drop of 10 Ω and were stopped when a maximum cut-off LI drop of <40 Ω was observed. Successful single RF ablation was defined according with a reduction of signal voltage by at least 50% and inability to capture local tissue on pacing. The ablation endpoint was PVI as assessed by entrance and exit block. Follow-up were scheduled at 3, 6 and 12 months post-ablation. Results 153 consecutive patients (61% paroxysmal AF, 39% persistent AF) were enrolled in the study. 3556 point-by-point first-pass RF applications of >10 s duration were performed around PVs. The mean LI drop was 13 ± 8Ω, the mean τ was 18.7 ± 13s and the median LI drop/τ was 0.67 [QI-QIII, 0.37 – 1.17] Ω/s. Both absolute drops in LI and LI drop/τ were greater at successful ablation sites (n = 3122, 88%) than at ineffective ablation sites (n = 434, 12%) (14 ± 8Ω vs 6 ± 4Ω, p < 0.0001 for LI; 0.73[0.41–1.25]Ω/s vs 0.35[0.22–0.59]Ω/s for LI drop/τ, p < 0.0001). Every 5-point increment in LI drop was associated with successful ablation, with an OR of 3.13 (95%CI: 2.7 to 3.6, p < 0.0001), reaching the highest point when a value larger than 15 Ω was observed (99.9% of acute success). A significant trend was observed from lower to higher LI drop/τ values and a value greater than 0.65 Ω/s (best cut-off value on the basis of the ROC analysis) was significantly associated with successful RF delivery with an OR of 5.54 (95%CI: 4.31 to 7.11, p < 0.0001). No complications occurred during and after procedures. At 1-year follow-up, the AF recurrence rate was 12% after the 90-day blanking period. Conclusions The magnitude and time-course of the LI drop during RF delivery were associated with effective lesion formation. This ablation strategy for PVI guided by LI technology proved safe and effective, and resulted in a very low rate of AF recurrence over 1-year follow-up.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
L Segreti ◽  
A De Simone ◽  
V Schillaci ◽  
G Zucchelli ◽  
C Pandozi ◽  
...  

Abstract Background Recently, a novel technology able to measure local tissue impedance (LI) providing a measure of tissue characteristics aimed at validating confidently ablation endpoints has become available for clinical use. Purpose We report the outcomes of our acute and long-term clinical evaluation of this algorithm in consecutive atrial fibrillation ablation cases. Methods Consecutive patients (pts) undergoing AF ablation at 6 Italian centers were included in the CHARISMA registry. A novel RF ablation catheter and a dedicated algorithm were used to measure LI through the distal catheter's electrode. The ablation was guided by looking at the magnitude and time course of impedance drop during RF delivery. The maximum distance between each ablation spot (center-to-center) was suggested to be ≤4 mm. RF applications were targeted to a LI drop of 10 Ω and RF applications were stopped when a maximum cutoff LI drop of <40 Ω was observed. Successful single RF ablation was defined according with a reduction of signal voltage (RedV) by at least 50% and inability to capture local tissue on pacing. Ablation endpoint was PVI as assessed by entrance and exit block. Post-ablation, all pts were monitored with ambulatory event monitoring, as well as Holter monitoring at 3, 6, and 12 months post-ablation. Additional ECG monitoring was performed as indicated by patient symptoms. Results A total of 1914 point by point first pass RF applications >10 s performed around PVs were analyzed from 98 pts (mean age = 61±11 years, 69% male, 55% paroxysmal AF, 45% persistent AF, 60% de novo procedures, 40% redo procedures). The mean LI was 105±15Ω prior to ablation and 92±13Ω after ablation (p<0.0001, mean absolute LI drop of 12.7±8Ω) during a median RF delivery time of 22 [17–31] sec. Effective ablation spots (88%) showed a higher absolute impedance drop (13.6±8Ω at effective RedV vs 6±3Ω at ineffective RedV, p<0.0001) compared with ineffective sites (12%). No steam pops or complications, including atrio-esophageal fistula or tamponade were reported during or after the procedures. At the end of the procedures all PVs were successfully isolated in all study pts. During a median follow-up of 369 [287–446] days, 13 pts (13.2%) developed an AF/AT recurrence after the 90-days blanking period (9.2% with paroxysmal vs 18% with persistent AF, p=0.239; 8.5% for de novo vs 20.5% for redo procedures, p=0.127). The time to recurrence was comparable among AF type (HR=1.97; 0.66 to 5.86; log-rank p=0.2265 for persistent vs paroxysmal AF) and procedural type (HR=2.56; 0.84 to 7.82; log-rank p=0.087 for redo vs de novo procedure) Conclusions In our experience, the magnitude of the LI drop during RF delivery was associated with effective lesion formation. An ablation strategy for PVI guided by LI technology was safe and effective, and resulted in a very low recurrence rate of AF at 1-year follow-up irrespective of paroxysmal/persistent AF type or de novo/redo procedure. Funding Acknowledgement Type of funding source: None


2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
J Borrego Rodriguez ◽  
C Palacios Echevarren ◽  
S Prieto Gonzalez ◽  
JC Echarte Morales ◽  
R Bergel Garcia ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION CRH in patients with ischemic heart disease is recommended by the different clinical practice guidelines with an IA level of evidence, with an important role in reducing cardiovascular mortality and hospital readmissions during follow-up. OBJECTIVE The goal of this study is to show the 4-year clinical results of a population of patients who participated in an CRH program after an Acute Coronary Syndrome (ACS). METHODS Between May/2014 and September/2017, 221 patients who had recently presented an ACS completed the 12 weeks of phase II of the CRH program at our center. In May/2020 we collected epidemiological, clinical and echocardiographic information at the time of the acute cardiovascular event; and we evaluate the current vital status of the patients and the incidence of readmissions for: angina, HF, new ACS, or arrhythmic events. RESULTS Of the 221 patients, 182 were men (82%). The mean age of our population was 58.3 ± 7.8 years. 58% (129 patients) suffered from ST-elevation ACS. The mean time of hospital stay was 6.20 ± 2.9 days. An echocardiogram was performed at discharge, which showed an average LVEF of 56 ± 6%. Eight patients (4%) developed early Ventricular Fibrilation (VF) during the acute phase of ACS. Among the classic CVRF, smoking (79%) was the most prevalent, followed by dyslipidemia (53%) and hypertension (47%). The mean time from hospital discharge to the start of phase II RHC was 42 ± 16 days. The overall incidence of events was 9%: 10 patients suffered reinfarction during follow-up, and 7 were readmitted for unstable angina, all of whom underwent PCI; no patient was admitted for HF; and none of the 8 patients with early VF had a new tachyarrhythmia, registering a single admission for VT during follow-up. None of the patients had sustained ventricular tachyarrhythmias during exercise-training. At the mean 4.5-year follow-up, 218 patients were still alive (98%). CONCLUSION The incidence of CV events in the follow-up of our cohort was low, which can be explained by the fact that it is a young population, with an LVEF at low limits of normality at discharge, which is one of the most important predictors in the prognosis after an ischemic event. As an improvement, we must shorten the time until the start of phase II of the program. CRH shows once again its clinical benefit after an ACS, in consonance with the existing evidence. Abstract Figure. Outcomes of a CRH program.


2014 ◽  
Vol 86 (4) ◽  
pp. 325 ◽  
Author(s):  
Saverio Forte ◽  
Pasquale Martino ◽  
Silvano Palazzo ◽  
Matteo Matera ◽  
Floriana Giangrande ◽  
...  

Introduction: The intrarenal resistance index (RI) is a calculated parameter for the assessment of the status of the graft during the follow-up ultrasound of the transplanted kidney. Currently it is still unclear the predictive value of RI, also in function of the time. Materials and Methods: We retrospectively investigated the correlation between the RI and the graft survival (GS) and the overall survival (OS) after transplantation. We evaluated 268 patients transplanted between 2003 and 2011, the mean followup was 73 months (12-136). The RI was evaluated at 8 days, 6 months, 1 year and 3 years. The ROC analysis was used to calculate the predictive value of RI and the Kaplan Mayer curves was used to evaluated the OS and PS. Results: The ROC analysis, correlated to the GS, identified a value of RI equal to 0.75 as a cut-off. All patients was stratified according to the RI at 8 days (RI ≤ 0,75: 212 vs RI > 0.75: 56), at 6 months (RI ≤ 0.75: 237 vs RI > 0.75: 31), at 1 year (RI ≤ 0.75: 229 vs RI > 0.75: 39) and at 3 years (RI ≤ 0.75: 224 vs RI > 0.75: 44). The RI showed statistically significant differences between the two groups in favor of those who had an RI ≤ 0.75 only at 8 days and at 6 moths (p = 0.0078 and p = 0.02 to 8 days to 6 months) on the GS. On the contrary, we observed that the RI estimated at 1 year and 3 years has not correlated with the GS. The same RI cut-off was correlate with PS after transplantation. We observed that there are no correlations between the RI and OS. Conclusions: The RI proved to be a good prognostic factor on survival organ when it was evaluated in the first months of follow- up after transplantation. This parameter does not appear, however, correlate with OS of the transplanted subject.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
G R Rios-Munoz ◽  
N Soto ◽  
P Avila ◽  
T Datino ◽  
F Atienza ◽  
...  

Abstract Introduction Treatment of atrial fibrillation (AF) remains sub-optimal, with low success in pulmonary vein isolation (PVI) ablation procedures in long-standing-persistent AF patients. The maintenance mechanisms of AF are still under debate. Rotational activity (RA) events, also known as rotors, may play a role in perpetuating AF. The characterisation of these drivers during electroanatomical (EA) guided ablation procedures in relationship with follow-up and recurrence ratios in AF patients is necessary to design new ablation strategies to improve the AF treatment success. Purpose We report an AF patient cohort of endocardial mapping and PVI ablation procedures with additional RA events detected during the EA study. We aim to study the presence and distribution of RA in AF patients and its impact on AF recurrence when only PVI ablation is performed. Methods 75 persistent consecutive AF patients (age 60.7±9.8, 74.7% men) underwent EA mapping and RA detection with an automatic algorithm. The presence of RA was annotated on the EA map based on the unipolar electrograms (EGMs) registered with a 20-pole catheter. RA presence was analysed at different left atrial locations (37.2±14.8 sites per patient). AF recurrence was evaluated in follow-up after treatment. Results At follow-up (9±5 months), 50% of the patients presented AF recurrence. Patients with RA had more dilated atria in terms of volumes (p=0.002) and areas (p=0.001). Patients with RA exhibited higher mean voltage EGMs 0.6±0.3 mV vs 0.5±0.2 mV (p=0.036), with shorter cycle lengths 169.1±26.0 ms vs. 188.4±44.2 ms (p=0.044). Finally, patients with RA presented more AF recurrence rates than patients with no RA events (p=0.007). No significant differences were found in terms of comorbidities, e.g., heart failure, hypertension, COPD, stroke, SHD, or diabetes mellitus. Conclusions The results show that patients with more RA events and those with RA outside the PVI ablated regions presented higher AF recurrence episodes than those with no RA or events inside the areas affected by radio-frequency ablation. The study suggests that further ablation treatment of the areas harboring RA might be necessary to reduce the recurrence ratio in AF patients. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III; Sociedad Española de Cardiología


1986 ◽  
Vol 1 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Furio Pacini ◽  
Rossella Elisei ◽  
Stefano Anelli ◽  
Lucia Gasperini ◽  
Ernestina Schipani ◽  
...  

The utility of determining circulating neuron-specific enolase (NSE) in medullary thyroid carcinoma was assessed in 25 patients followed up for a mean period of 45.6 months. In 5 patients tested before any treatment serum NSE concentrations were in the normal range. After total thyroidectomy abnormally high serum NSE concentrations (more than 9.8 ng/ml) were found in 1/3 patients with normal calcitonin (CT) in remission, in 2/10 with elevated CT levels but no evidence of disease and in 9/12 with elevated CT levels and documented metastases. The mean (± SD) NSE value in this last group was 12.0 ± 12.6 ng/ml, significantly higher than in the other groups (p < 0.005). The time course of serum NSE in patients with long follow-up seems to indicate that serum NSE rises when a large tumor mass is present and usually parallels the pattern of circulating CT. Effective treatment of the metastases is usually followed by reduction of serum NSE. Thus, serum NSE can serve as an additional humoral marker for medullary thyroid carcinoma, its elevation being associated with important metastatic involvement and with a poor prognosis of the tumor.


2006 ◽  
Vol 16 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Tugcin Bora Polat ◽  
Yalim Yalcin ◽  
Celal Akdeniz ◽  
Cenap Zeybek ◽  
Abdullah Erdem ◽  
...  

Background:Disturbances of conduction are well known in the setting of acute rheumatic fever. The aim of this study is to investigate the QT dispersion as seen in the surface electrocardiogram of children with acute rheumatic fever.Methods:QT dispersion was quantitatively evaluated in 88 children with acute rheumatic fever. Patients were divided into two groups based on the absence or presence of carditis. As a control group, we studied 36 healthy children free of any disease, and matched for age with both groups. Repeat echocardiographic examinations were routinely scheduled in all patients at 3 months after the initial attack to study the evolution of valvar lesions.Results:The mean QT dispersion was significantly higher in children with rheumatic carditis. But there was no statistical difference between children without carditis and normal children. Among the children with carditis, the mean dispersion was higher in those with significant valvar regurgitation. Dispersion of greater than 55 milliseconds had a sensitivity of 85%, and specificity of 70%, in predicting rheumatic carditis, while a value of 65 milliseconds or greater had sensitivity of 81% specificity of 85% in predicting severe valvar lesions in acute rheumatic carditis. At follow-up examination, a clear reduction on the QT dispersion was the main finding, reflecting an electrophysiological improvement.Conclusions:These observations suggest that QT dispersion is increased in association with cardiac involvement in children with acute rheumatic fever.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Tilz ◽  
C L Lenz ◽  
P S Sommer ◽  
N Sawan ◽  
R Meyer-Saraei ◽  
...  

Abstract Background Based on the assumption of trigger elimination, pulmonary vein isolation (PVI) currently presents the gold standard of atrial fibrillation (AF) ablation. Recently, rapidly spinning rotors or focal impulse formation has been raised as a crucial sustaining mechanism of AF. Ablation of these rotors may potentially obviate the need for trigger elimination with PVI. Purpose This study sought to compare the safety and effectiveness of Focal Impulse and Rotor Modulation (FIRM) guided catheter ablation only with the gold standard of pulmonary vein isolation (PVI) in patients with paroxysmal AF. Methods This was a post-market, prospective, single-blinded, randomized, multi-center trial. Patients were enrolled at three centers and equally (1:1) randomized between those undergoing conventional RF ablation with PVI (PVI group) vs. those treated with FIRM-guided RF ablation without PVI (FIRM group). Data was collected at enrollment, procedure, and at 7-day, 3-month, 6-month, and 12-month follow-up visits. The study was closed early by the sponsor. At the time of study closure, any pending follow-up visits were waived. Results From February 2016 until February 2018, a total of 51 (out of a planned 170) patients (mean age 63±10.6 years, 57% male) were enrolled and randomized. Four patients withdrew from the study prior to treatment, resulting in 23 patients allocated to the FIRM group and 24 in the PVI group. Only 13 patients in the FIRM group and 11 patients in the PVI group completed the 12-month follow-up. Statistical analysis was not completed given the small number of patients. Single-procedure effectiveness (freedom from AF/atrial tachycardia recurrence after blanking period) was 52.9% (9/17) in the FIRM group and 85.7% (12/14) in the PVI group at 6 months; and 31.3% (5/16) in the FIRM group and 80% (8/10) in the PVI group at 12 months. Repeat procedures were performed in 45.8% (11/24) patients in the FIRM group and 7.4% (2/27) in the PVI group. The acute safety endpoint [freedom from procedure-related serious adverse events (SAE)] was achieved in 87% (20/23) of FIRM group patients and 100% (24/24) of PVI group patients. Procedure related SAEs occurred in three patients in the FIRM group: 1 femoral artery aneurysm and 2 injection site hematomas. No additional procedure-related SAEs were reported >7 days post-procedure. Conclusions These partial study effectiveness results reinforce the importance of PVI in paroxysmal atrial fibrillation patients and suggest that FIRM-guided ablation alone (without PVI) is not an effective strategy for treatment of paroxysmal AF in most patients. Further study is needed to understand the effectiveness of adding FIRM-guided ablation as an adjunct to PVI in this patient group. Acknowledgement/Funding Abbot


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
H E Lim ◽  
J Ahn ◽  
S J Han ◽  
J Shim ◽  
Y H Kim ◽  
...  

Abstract Background Risk factors for the occurrence of embolic stroke (ES) after atrial fibrillation (AF) ablation have not been fully elucidated. Our aim was to assess incidence of ES during long-term follow-up following AF ablation and to identify predicting factors associated with post-ablation ES. Methods We enrolled patients who experienced ES after AF ablation and body mass index-matched controls from AF ablation registries. Epicardial adipose tissue (EAT) was assessed using multislice computed tomography prior to ablation. Results A total of 3,464 patients who underwent AF ablation were recruited. During a mean follow-up of 47.2 months, ES occurred in 47 patients (1.36%) with a mean CHA2DS2-VAS score of 2.15 and overall incidence of ES was 0.34 per 100 patients/year. Compared with control group (n=190), ES group had more higher prior thromboembolic event and AF recurrence rates, larger LA size, lower creatinine clearance rate (CCr), and greater total and periatrial EAT volumes although no differences in AF type, CHA2DS2-VASc score, ablation extent, and anti-thrombotics use were found. On multivariate regression analysis, a prior history of thromboembolism, CCr, and periatrial EAT volume were independently associated with ES occurrence after AF ablation. Cox regression analysis Risk factor Univariate Multivariate HR (95% CI) p value HR (95% CI) p value Age 1.017 (0.984–1.051) 0.31 Prior thromboembolism 2.488 (1.134–5.460) 0.023 2.916 (1.178–7.219) 0.021 CHA2DS2-VASc score 1.139 (0.899–1.445) 0.282 CCr 0.984 (0.970–0.999) 0.038 0.982 (0.996–0.998) 0.029 LA diameter (mm) 1.070 (1.012–1.130) 0.017 1.072 (0.999–1.150) 0.054 EAT_total (ml) 1.020 (1.010–1.029) <0.001 1.008 (0.993–1.023) 0.297 EAT_periatrial (ml) 1.085 (1.045–1.126) <0.001 1.065 (1.005–1.128) 0.032 PVI + additional ablation 0.846 (0.460–1.557) 0.592 No anticoagulant use 0.651 (0.346–1.226) 0.184 Recurrence 2.011 (1.007–4.013) 0.048 1.240 (0.551–2.793) 0.603 CCr, creatinine clearance rate; EAT, epicardial adipose tissue; LA, left atrium; PVI, pulmonary vein isolation. K-M curve for stroke-free survival Conclusions Incidence of ES after AF ablation was lower than expected rate based on CHA2DS2-VASc score even though anticoagulants use was limited. Periatrial EAT volume, a prior thromboembolism event, and CCr were independent factors in predicting ES irrespective of AF recurrence and CHA2DS2-VASc score in patients who underwent AF ablation.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
T Fujino ◽  
H Yuzawa ◽  
T Kinoshita ◽  
M Shinohara ◽  
H Koike ◽  
...  

Abstract Background Oral anticoagulant therapy (OAT) is effective for preventing strokes in atrial fibrillation (AF) patients. Currently, there is controversy regarding the discontinuation of OATs in patients with ablation procedures to eliminate AF. Aim We investigated the incidence of major bleeding and ischemic strokes/systemic embolisms in low-risk patients that discontinued OATs after successful AF ablation procedures. Methods Of 330 consecutive patients that underwent AF ablation procedures and were prescribed one of the direct oral anticoagulants or warfarin, 207 AF patients (158 men, mean age 61±11 years) who discontinued OATs three months after the procedure were enrolled. The average CHADS2 and HAS-BLED scores were 1.0±0.9 and 1.2±1.0, respectively, which meant that most patients had a low risk for strokes. Results During follow-up, 31 patients (15%) had recurrences of AF. Those patients underwent a re-ablation procedure and then re-discontinued their OATs three months after the session. During a 60±13 months follow-up, major bleeding was observed in five patients (2.4%) and was associated with a higher HAS-BLED score (2.2±0.4 vs. 1.1±1.0, P=0.027). In contrast, none of the patients experienced ischemic strokes/systemic embolisms. Conclusions This prospective study demonstrated that in patients with successful ablation procedures and low risk scores for AF management, OATs could be discontinued three months after the procedure. Unnecessary continuation of OATs may increase the incidence of major bleeding during the follow-up.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D J Nascimento Matos ◽  
D Cavaco ◽  
G Rodrigues ◽  
J Carmo ◽  
M S Carvalho ◽  
...  

Abstract Introduction Pulmonary vein (PV) reconnection is a common cause of relapse after catheter ablation of atrial fibrillation (AF). However, some patients have AF recurrence despite durable PV isolation. The aim of this study was to assess the PV isolation status at the time of a second catheter ablation (redo) procedure, and its relationship with subsequent AF relapse. Methods Consecutive patients with symptomatic drug-resistant AF who underwent redo procedures from January 2006 to December 2017 were identified in a single-center observational registry. Pulmonary vein isolation status was assessed during the electrophysiologic study with a circular mapping catheter. Additional radiofrequency (RF) energy applications were also recorded. AF relapse was defined as symptomatic or documented AF/atrial tachycardia/atrial flutter after a 3-month blanking period. Results We identified 240 patients (77 [32%] females, median age 61 [IQR 53–67] years, 85 [35%] with non-paroxysmal AF) undergoing redo procedures during the study period. At the time of redo, 17 (7%) of the patients presented bidirectional conduction block of all PVs. PV reconnection occurred in 157 (65%) of cases in the left superior vein, 142 (59%) in the left inferior vein, 177 (73%) in the right superior vein, and 163 (68%) in the right inferior vein (table). All of the PVs were reconducted in 91 (38%) patients. Additional RF applications were performed in the left atrium (LA) roof, LA posterior wall, cavotricuspid isthmus, mitral isthmus, superior vena cava, coronary sinus, and left atrial appendage ostium, at the operator's discretion (table 1). Over a median follow-up of 2-years (IQR 1–5), 126 patients (53%) suffered AF recurrence, yielding a mean relapse rate of 17%/year. In multivariate Cox regression analysis, the lack of PV reconnection at the time of redo emerged as an independent predictor of subsequent relapse (HR 1.97, 95% CI 1.12–3.49, p=0.019) even after adjustment for univariate predictors including non-paroxysmal AF, body mass index, female sex, and active smoking. Conclusion In patients undergoing redo AF ablation procedures, less than 10% present with complete PV isolation. Despite being relatively infrequent, this finding is independently associated with greater likelihood of subsequent recurrence, suggesting that other mechanisms, not fully addressed by additional RF applications, are at play.


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