Radiofrequency Catheter Ablation Procedures Research Articles

Radiation dose to the eye of physicians during radio frequency catheter ablation: a small-scale study.

Radio frequency catheter ablation (RFCA), a treatment for arrhythmia, requires a long fluoroscopy time that increases the radiation exposure dose to the physician, particularly to the lens of the eye. It is recommended that a lens-specific dosimeter such as DOSIRIS® is used to measure the dose to the lens. In this study, we investigated whether conventional glass badges can be used as an alternative to lens dosimeters. The doses to the lenses of two physicians (physician A, main operator; physician B, assistant; physician B was further away from the patient than physician A) were measured for 126 RFCA procedures performed over a 6-month period (fluoroscopy rate of 3.0 p/s with use of a ceiling-hanging shield). The cumulative value measured by a lens dosimeter attached to the inside of Pb glasses (0.07-mm dose equivalent) next to the left eye was 4.7mSv for physician A, and 0.8mSv for physician B. The reading on the glass badge worn on the left side of the neck was 4.7mSv for physician A and 1.3mSv for physician B. Lens dosimeter and glass badge values showed a good correlation for the left eye and left neck (r = 0.86, p < 0.01). We show that glass badges may be a viable alternative to lens-equivalent dosimetry when using low-pulse fluoroscopy and a ceiling-hanging shield.

Ventricular arrhythmias originating from different portions of the communicating vein of the left ventricular summit: electrocardiographic characteristics and catheter ablation

BackgroundIdiopathic ventricular arrhythmias (IVAs) arising from different portions of the communicating vein of the left ventricular summit (summit-CV) are not a rare phenomenon. Whereas its electrocardiographic (ECG) and electrophysiological characteristics are not fully investigated.ObjectiveThis study aimed to identify distinct ECG and electrophysiological features of IVAs originating from different portions of summit-CV.MethodsNineteen patients confirmed arising from summit-CV were included in this study.ResultsThe 19 patients were divided into proximal and distal portion groups based on their target sites in summit-CV. In the proximal portion group, 100% (11/11) VAs showed dominant negative (rs or QS) waves in lead I, while in the distal portion group, 87.5% (7/8) showed dominant positive waves (R, Rs or r) (p < 0.000). In lead V1, 100% (11/11) of the proximal portion group showed dominant positive waves (R or Rs), while 62.50% (5/8) of the distal portion group showed positive and negative bidirectional or negative waves (RS or rS) (p < 0.005). RI>4mV, SI<3.5mV, RV1<13mV, SV1>3.5mV, RI/SI>0.83, and RV1/SV1< 2.6 indicated a distal portion of summit-CV with the predictive value of 0.909, 1.000, 0.653, 0.972, 0.903, 0.966, respectively. A more positive wave in lead I and a more negative wave in lead V1 indicated more distal origin in summit-CV. Target sites in proximal and distal summit-CV groups showed similar electrophysiological characteristics during mapping.ConclusionsThere were significant differences in ECG characteristics of VAs at different portions of summit-CV, which could aid pre-procedure planning and facilitate radiofrequency catheter ablation (RFCA) procedures.

Impact of patent foramen ovale with left-to-right shunt on atrial fibrillation ablation in young patients

ObjectiveThe CABANA study shows that atrial fibrillation (AF) paitents younger than 65 years benefit more from the AF radiofrequency catheter ablation (RFCA) procedure. The aim of this study is to investigate the impact of inherent patent foramen ovale (PFO) with a Left-to-Right Shunt on the RFCA procedure in young AF patients. MethodsBased on the presence or absence of inherent PFO, the AF patients were divided into the PFO groups and the non-PFO group. Clinical follow-up was also investigated. ResultsA total of 285 AF patients were enrolled. PFO was detected by TEE in 42 patients. The age of patients at initial AF onset was younger in the PFO group than in the non-PFO group (58.3 ± 8.9 vs. 62.3 ± 9.6 years, P = 0.012). There were more AF patients aged <55 years in the PFO group than in the non-PFO group. For the 9 AF patients with PFO who experienced AF recurrence and the left-to-right shunts decreased in size in 5 of the patients aged <65 years. The LAD decreased in those patients. In the PeAF patients, 53/64 patients aged <65 years and 23/40 patients aged older than 65 years were free of AF (82.8 % vs. 57.5 %, respectively; P = 0.005). ConclusionSuccess is not affected when AF is combined PFO compared with AF without PFO. Young patients have better PeAF RFCA outcomes. AF in young patients with left atria enlargement and a serious AF burden, may lead to reduced EF and render PFO easy to detect.

Relationship between Lesion Parameters after Radiofrequency Catheter Ablation in Striated Muscles and Parenchymal Tissue.

Background and Objectives: Radiofrequency catheter ablation (RFCA) is a highly successful intervention. By comparing the lesion changes in prostate parenchymal and striated muscle tissues after RFCA with and without cooling, it was possible to assess the correlation between the shape regularity, area, and perimeter of the thermal lesion, and to predict the geometric shape changes of the lesions. Materials and Methods: A standard prostate and striated muscle RFCA procedure was performed on 13 non-purebred dogs in two sessions: no cooling and cooling with 0.1% NaCl solution. Microtome-cut 2-3 µm sections of tissue samples were stained with haematoxylin and eosin and further examined. The quotient formula was employed to evaluate the geometric shape of the damage zones at the ablation site. Results: The extent of injury following RFCA in striated muscle tissue was comparable to that in prostate parenchymal tissue. Regression analysis indicated a strong and positive relationship between area and perimeter in all experimental groups. In the experimental groups of parenchymal tissues with and without cooling, an increase in the area or perimeter of the damage zone corresponded to an increase in the quotient value. A similar tendency was observed in the striated muscle group with cooling. However, in the striated muscle group without cooling, an increase in lesion area or perimeter lowered the quotient value. Standardised regression coefficients demonstrated that in the striated muscle with cooling, the damage zone shape was more determined by area than perimeter. However, in the parenchymal tissue, the perimeter had a more substantial impact on the damage zone shape than the area. Conclusions: The damage area and perimeter have predictive power on the overall shape regularity of damage zone geometry in both striated muscles and parenchymal tissue. This approach is employed to achieve a balance between the need for tumour eradication and the minimisation of ablation-induced complications to healthy tissue.

Injury to the sinus nodal artery during radiofrequency ablation of atrial fibrillation and atrial tachycardia: its prevalence and treatment with percutaneous coronary intervention

Abstract Background/Introduction Injury to the sinus node artery (SNA) leading to SN dysfunction during radiofrequency catheter ablation (RFCA) of atrial Fibrillation (AF) and atrial tachycardia (AT) has been reported. Purpose The purpose of this study was to elucidate the prevalence and clinical course of SNA injuries during RFCA of AF/AT and examine the efficacy of the percutaneous coronary intervention (PCI) to restore SN function. Methods We retrospectively analyzed data from 6,906 consecutive patients (pts) who underwent RFCA of AF/AT (6,379 pts with AF ablation and 527 pts with AT ablation) in two institutions between January 2013 and December 2022. Results Among 6,906 pts, 9 (0.13%) pts developed SN dysfunction due to SNA injury during RFCA (8 with AF, 1 with AT). Acute SNA injury (total occlusion or severe narrowing of the SNA) was confirmed by coronary angiography (CAG) during the RFCA session in 8/9 pts. In the remaining patient, SNA injury was suspected based on the CT angiography. The culprit sites of the SNA injury were located at the septal site of the superior vena cava-right atrium junction in 4 pts (44%), on the left atrial appendage ridge in 3 (33%), on the roof of the left atrium adjacent to the right superior pulmonary vein in 1 (11%), and in the persistent left superior vena cava in 1 (11%). PCI to the occluded SNA was performed in 8 of the 9 pts: 1) coronary blood flow of the SNA was restored by a 0.014" guidewire advancement into the occluded artery using a micro-catheter followed by direct nitroprusside injection in 4 pts; 2) the direct balloon angioplasty using 0.75-1.5 mm diameter balloons was required to maintain the blood flow of SNA in 3 pts; and 3) CAG revealed spontaneous recovery of the blood flow of SNA in one pt. The remaining patient did not receive the CAG/PCI. All 8 pts who underwent the PCI resulted in restoration of normal sinus rhythm. During a median of 44 months follow-up, all 8 pts who received the PCI maintained normal sinus rhythm, while one patient without PCI demonstrated persistent SN dysfunction. Conclusions SNA injury during RFCA is a rare but critical complication. Prompt recognition by CAG and subsequent PCI effectively restores SN function in pts with unexpected SN dysfunction during RFCA procedures.

Stroke and Bleeding Risks of Endocardial Ablation for Ventricular Arrhythmias

BackgroundRisks of radiofrequency catheter ablation for ventricular arrhythmias include emboli and bleeding complications but data on antithrombotic regimens are limited and guidelines do not specify a systematic approach. ObjectivesThis study sought to assess embolic and bleeding complications in relation to pre-periprocedure and post-periprocedure antithrombotic regimens. MethodsProspective assessment for complications was performed for 663 endocardial radiofrequency catheter ablation procedures in 616 consecutive patients (median age 64 years [Q1-Q3: 54-73 years], 70.3% men, 71.6% with cardiomyopathy, 44.5% with sustained ventricular tachycardia). ResultsThere were 2 strokes (0.3%; 95% CI: 0.0%-0.8%), 1 transient ischemic attack (0.15%), and 2 pulmonary emboli (0.3%). There were 39 bleeding complications (5.9%) including 11 pericardial effusions (1.7%), and 28 related to vascular access (4.2%). Consistent with the prevalence of coronary artery disease (47.5%), atrial fibrillation (30.0%), and prior stroke (10.6%), preprocedure, 464 patients (70.0%) were taking antithrombotic agents including 220 (33.2%) taking aspirin alone (ASA), and 163 (24.6%) taking warfarin or a direct acting oral anticoagulant (DOAC). Preprocedure non-ASA antiplatelet use (OR: 2.846; P = 0.011) and DOAC use (OR: 2.585; P = 0.032) were associated with risk of bleeding complications. Following ablation, 49.8% of patients were treated with ASA 325 mg/d and 30.3% received DOACs or warfarin. New DOAC or warfarin administration was initiated in only 6.6% of patients. Overall, 39.7% of patients continued the same preprocedure antithrombotic regimen. ConclusionsStroke is a rare complication of radiofrequency catheter ablation for ventricular arrhythmia using ASA 325 mg/d as a minimal postprocedure regimen with more potent regimens for selected patients.

Combined Radiofrequency Ablation and Left Atrial Appendage Closure in Atrial Fibrillation and Systolic Heart Failure.

Managing patients with atrial fibrillation (AF) and comorbid heart failure (HF) with reduced (HFrEF) or mildly reduced ejection fraction (HFmrEF) is of clinical importance but a great challenge. This study aimed to evaluate the clinical benefit of the combined radiofrequency catheter ablation (RFCA) and left atrial appendage closure (LAAC) procedure in AF patients complicated with systolic HF. AF patients with HFrEF or HFmrEF who underwent the combined RFCA and LAAC procedure were prospectively enrolled in the LAACablation registry. The procedural complications and long-term outcomes were evaluated. Another cohort of AF patients with systolic HF who did not undergo either RFCA or LAAC were used for prognosis comparison. Among 802 AF patients who underwent the combined procedure, 65 patients were comorbid with systolic HF (25 with HFrEF and 40 with HFmrEF). The overall procedural complication rate was 9.2%, which was mainly attributed to acute decompensated HF (6.2%). Accompanied with markedly reduced AF burden (from median [25th, 75th percentile]: 100 [100, 100] to 0 [0, 1.2]%, p < 0.001), upward trajectories of cardiac function were observed in 51 (78.4%) patients, showing improvement in New York Heart Classification (p < 0.01), natriuretic peptide levels (from 1492 [809, 3259] to 413 [163, 880] pg/mL, p < 0.001) and left ventricular EF (from 42.6 ± 5.3 to 53.8 ± 8.2%, p < 0.001). During the 27-month follow-up period, death, thromboembolism, major bleeding, and HF rehospitalization were observed in three, one, one, and four patients, respectively. The observed event rates showed a significant reduction compared with the non-procedure AF-HF cohort (n = 138; for composite endpoint: hazard ratio: 2.509, 95% confidence interval: 1.415-4.449, p = 0.002) and with the respective rates predicted by risk scores. Combining RFCA and LAAC achieves acceptable safety and credible long-term efficacy in AF patients with systolic HF. Further randomized studies are warranted in a larger patient cohort.

Very-early symptomatic recurrence is associated with late recurrence after radiofrequency ablation of atrial fibrillation.

After radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF), the effect of very-early (within 48 h) symptomatic recurrence (VESR) on late (after 3 months of RFCA) recurrence (LR) has been seldomly reported. We aimed to explore the relationship between VESR and LR among post-RFCA patients. This was a single-centre prospective cohort study that enrolled 6887 AF patients who received the first RFCA procedure from June 2018 to December 2021 at Beijing Anzhen Hospital. Patients were divided into four groups based on VESR and early (from 48 h to 3 months after RFCA) recurrence (ER): Group A (no VESR, no ER); Group B (VESR but no ER); Group C (ER but no VESR); and Group D (both VESR and ER). Three hundred and thirty (4.79%) patients experienced VESR (Groups B and D). With an average follow-up of 14.7 months after grouping, the Kaplan-Meier curve showed that LR risk in VESR patients was higher than in other patients (log-rank, P < 0.001), and the difference was significant in both paroxysmal (log-rank, P < 0.001) and persistent (log-rank, P < 0.001) AF patients (P for interaction = 0.118). In multivariate analysis, Groups B, C, and D were associated with a 2.161-, 5.409-, and 7.401-fold increase in the risk of LR, respectively. What is more, compared with Group A, VESR-atrial tachycardia and VESR-AF were related to a 3.467- and 5.564-fold LR risk, respectively. In VESR patients, classification based on ER and VESR modes improved the prediction potential of LR risk. Very-early symptomatic recurrence is associated with an increased risk of LR.

Clinical effectiveness and efficiency of a new steerable sheath technology for radiofrequency ablation in Chinese patients with atrial fibrillation: a retrospective comparative cohort study.

The clinical effectiveness and efficiency of a steerable sheath for radiofrequency catheter ablation (RFCA) in Chinese patients with atrial fibrillation (AF) needs to be compared with a fixed curve sheath to optimize RFCA procedure. This retrospective study included adult AF patients with their first RFCA that was conducted by the same electrophysiologist using a steerable sheath (VIZIGO, Biosense Webster, Inc.) or a fixed curve sheath (NaviEase, Synaptic Medical) in a Chinese tertiary care hospital from January to November 2021. The medical records kept at the hospital were the source of study data that included patient baseline characteristics and outcome measures for the clinical effectiveness and efficiency of RFCA procedure. Multivariate generalized linear regression analyses were performed to explore the impact of sheath type on clinical effectiveness and efficiency after adjustment. Fourteen patients using steerable sheath and 34 patients using fixed curve sheath for RFCA were included in the data analysis. Most of patient baseline characteristics associated with the two study groups were comparable except that the steerable sheath group had significantly higher left atrium diameter (41.9±6.5 vs. 38.1±3.9 mm, P=0.017) and larger left atrium volume (150.4±29.5 vs. 126.8±27.5 mL, P=0.017) than the fixed curve sheath group. Using steerable sheath was associated with significantly shorter total pulmonary vein isolation (PVI) fluoroscopy time and post-surgery hospital length of stay (LOS) than using fixed curve sheath in both unadjusted comparisons (PVI fluoroscopy time: 1.3±1.5 vs. 4.0±3.9 min, P=0.004; post-surgery LOS: 2.1±0.7 vs. 2.9±1.5 days, P=0.034) and multivariate generalized regression analyses (PVI fluoroscopy time: coefficient =-0.859, P=0.014; post-surgery LOS: coefficient =-0.303, P=0.018). Compared to fixed curve sheath, steerable sheath used for RFAC could have the potential to shorten the PVI fluoroscopy time and reduce post-surgery LOS in a Chinese real-world hospital setting. Future real-world studies with large sample size are needed to confirm our study findings.

AB-453070-3 VERY-EARLY SYMPTOMATIC RECURRENCE IS ASSOCIATED WITH INCREASED RISK OF LATE RECURRENCE AMONG ATRIAL FIBRILLATION PATIENTS AFTER RADIOFREQUENCY ABLATION

The effect of very-early (within 48 h) symptomatic recurrence (VESR) of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) on late recurrence (LR) (after 3 months of RFCA) has been seldomly reported. To explore the relationship between VESR and LR among post-RFCA patients. We enrolled AF patients who registered in the Chinese Atrial Fibrillation Registry study and received the first RFCA procedure from June 2018 to December 2021 at Beijing Anzhen Hospital. Patients were divided into four groups based on VESR and early recurrence (ER) (from 48 h to 3 months after RFCA): group A (no VESR, no ER); group B (VESR but no ER); group C (ER but no VESR); and group D (both VESR and ER). Their clinical characteristics and risk of LR events were compared among groups. The study included 6887 patients; VESR was found in 330 (4.79% ) patients. The proportion of women in patients with VESR was higher (group B vs. group A: 40.65% vs. 32.03%, P=0.043; group D vs. group A: 39.13% vs. 32.03%, P=0.032), and the proportion of hypertensive patients was lower (group B vs. group A: 41.46% vs. 53.64%, P=0.007; group D vs. group A: 44.44% vs. 53.64%, P=0.009). With an average follow-up of 17.7 months, the Kaplan-Meier curve showed that LR risk in VESR patients was significantly higher than in other patients in both paroxysmal (log-rank, P<0.001) and persistent (log-rank, P<0.001) AF patients (P for interaction=0.118). In VESR patients, LR risk between group B and group D patients was significantly different (log-rank, P<0.001). Multivariate Cox regression showed that group B and group D were associated with increased risk of LR (HRB:A=2.161, P<0.001; HRD:A=7.401, P<0.001). In VESR patients, compared with the combination of variables in the APPLE score (Age, Persistent AF, imPaired eGFR, Left atrial diameter, left ventricular Ejection fraction), the combination of group and the APPLE score variables significantly improves AUC for predicting LR at 6 (73.2% vs. 58.2%, P<0.001), 12 (72.0% vs.60.5%, P<0.001), and 18 (69.2% vs. 50.3%, P=0.002) months. VESR is associated with increased risk of LR in both paroxysmal and persistent AF patients. Further, classification of VESR patients based on recurrence between 48 h and 3 months improves the prediction potential of LR risk in these patients.

Comparison of Myocardial Injury and Inflammation Biomarkers and Their Impact on Recurrence after Cryoballoon and Radiofrequency Ablation for Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Biomarkers of myocardial injury and inflammation were found to be different after radiofrequency catheter ablation (RFCA) and cryoballoon ablation (CBA) for atrial fibrillation (AF); however, the results are currently controversial. This study was aimed to systematically compare the differences in myocardial injury and inflammation biomarkers after RFCA and CBA procedures and to investigate their impact on AF recurrence. Databases, including PubMed, Embase, the Cochrane Library, ClinicalTrials.gov, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM), were systematically searched from their date of inception to May 2022. The primary outcomes of interest were the differences in myocardial injury and inflammation biomarkers after CBA and RFCA procedures for AF patients, and the impact of the biomarkers on AF recurrence. Secondary outcomes included the total ablation time, the procedure duration and the freedom from atrial tachycardia (AT). Eighteen studies with a total of 1807 patients were finally enrolled. CBA treatment was associated with significantly greater increases in troponin I (TNI) levels (weighted mean difference [WMD] = 3.13 ug/L, 95% confidence interval [CI] 2.43-3.64) both at 4-6 h (WMD = 3.94 ug/L), 24 h (WMD = 4.23 ug/L), 48 h (WMD = 2.14 ug/L) and 72 h (WMD = 0.56 ug/L), and also creatine kinade MB fraction (CK-MB) levels at 4-6 h (WMD = 33.21 U/L), 24 h (WMD = 35.84 U/L) and 48 h (WMD = 4.62 U/L), while RFCA treatment was associated with greater increases in postablation C-reactive protein (CRP) levels both at 48 h (WMD = -9.32 mg/L) and 72 h (WMD = -10.90 mg/L). The CBA and RFCA treatments had comparable rates of freedom from AT (74.5% vs. 75.2%, RR = 1.08). The CRP levels were significantly higher in patients with early recurrence of AF (ERAF) than in those without ERAF after RFCA treatment (WMD = 3.415 mg/L). The time-course patterns of postablation myocardial injury and inflammation biomarkers are different between RFCA and CBA procedures. The lower postprocedural elevation of myocardial injury biomarkers and the increased CRP levels may be predictive factors for ERAF. CRD42021278564.

Abstract 10683: Alternations in Autonomic Function During Pulmonary Vein Isolation Without Targeting Ganglionated Plexi Ablation in Patients With Atrial Fibrillation

Introduction: Abnormal autonomic innervation in the left atrium was reported to be related to developing/sustaining atrial fibrillation (AF). Autonomic denervation by radiofrequency catheter ablation (RFCA), evaluated by heart rate variability (HRV), is associated with a lower recurrence rate of AF. Ganglionated Plexi (GP) has been regarded as a target of autonomic denervation during the RFCA; however, the degree by which autonomic function is altered during the RFCA procedure remains unclear. Hypothesis:We tested the hypothesis that autonomic function is altered consistently during the ablation procedure without targeting GP. Method: Thirteen patients with paroxysmal AF who underwent pulmonary vein isolation (PVI) via RFCA were included (Age, 64.3 ± 1.9; Male/Female, 10/3). PVI was performed in the order prescribed (left superior, left inferior, right superior, and right inferior PV). HRV was assessed prior to, during each PV ablation, and post-ablation. Results: A vagal response (significant bradycardia) during the procedure was observed in three patients. The parameter of para-sympathetic nerve activity (para-SNA) (e.g., RMSSD, 38.7 ± 7.8 vs. 26.6 ± 6.0 ms, P &lt; 0.05), and total power of HRV (1861 ± 831 vs. 1105 ± 584 ms, P &lt; 0.05) were decreased by the procedure. While the balance of SNA to para-SNA (ratio of low to high frequency, LF/HF) was unchanged, which may indicate both SNA and para-SNA denervation. Using a linear mixed effect model, the effect of the “period” (i.e., pre, each PV, post) on the reduction in para-SNA parameter (HF) or total power of HRV was significant (both, P &lt; 0.05). The reduction was consistent in each PV, and post-hoc analysis (Bonferroni) showed significant differences only between baseline and post-RFCA in these parameters (P &lt; 0.05). Even in the patients without significant bradycardia response, the reduction in HRV parameter was significant in the linear mixed effect model (e.g., the effect of the “period” on RMSSD, P &lt; 0.05). Conclusion: We found that the PVI by RFA, without targeting GP, modified autonomic function, even in the patients who did not develop vagal responses. The HRV change was consistent during each PV isolation, which may suggest the non-necessity of GP ablation for autonomic modification by the ablation.

Abstract 14437: Safety of Fluoroless Radiofrequency Ablation for Atrial Fibrillation in Patients With Pre-Existing Cardiac Implantable Electronic Device

Introduction: Radiofrequency catheter ablation (RFA) for atrial fibrillation (AF) is being increasingly performed without fluoroscopy. There is limited experience in flouroless RFA for AF in patients with pre-existing cardiac implantable electronic devices (CIED). Hypothesis: The safety of Fluoroless RFA for AF in patients with pre-existing CIED is uncertain. Methods: In this single-center study, we retrospectively evaluated patients undergoing fluoroless RFA for AF with pre-existing CIED in situ. A total of two hundred and sixty-four (264) consecutive fluoroless RFA procedures for AF from 6/1/2019 to 5/2/2022 were evaluated. All procedures were performed with intracardiac echocardiography (ICE) support. We assessed rates of CIED-related complications and changes in lead parameters over 30 days of follow-up. Pre and post-ablation device interrogations were reviewed for interval changes and compared for any change in the device or lead parameters. Patients were tracked for any subsequent device malfunction. Results: Among 264 fluoroless AF ablations patients, 25 (9.5%) had pre-existing CIED (13 dual-chamber pacemakers, 4 dual-chamber defibrillators, 4 single-chamber defibrillators/pacemakers, and 4 biventricular devices). Mean age was 71.2 ± 6.0 years with mean duration of indwelling CIED was 1821.1 ± 1586.8 days (see Table). Two (0.07%) patients had lead-related fibrin on ICE imaging. There was no significant difference in lead(s) threshold, impedance, or sensing post-procedure or at 30-days follow-up compared to pre-procedure (see Table). There were no intra- or post-op thromboembolic events or subsequent device infection over 30 days of follow-up. None of the patients required lead revision. One patient underwent CIED extraction after 11 months for an unrelated secondary device infection. Conclusion: Radiofrequency catheter ablation for AF can be safely performed without fluoroscopy in patients with CIED.

High density catheter approach with liveview dynamic display improves procedural efficiency of atrial fibrillation ablation

Abstract Introduction PVI isolation confirmation after RF ablation is often time-consuming, especially in case of a single transeptal catheter approach into the left atrium. A novel Live View (LV) dynamic display mapping software, utilized in combination with the High Density (HD) Grid mapping catheter, allows to display beat-to-beat, dynamic regional mapping data. Purpose We evaluated the feasibility and the procedural impact of a procedural left atrial workflow with a single transeptal-single HD catheter analysis, incorporating the LV Mapping Software for the assessment of PVI after ablation. Methods Paroxysmal and persistent AF patients scheduled for AF ablation were prospectively enrolled. All patients underwent only PVI under LSI guidance (LSI between 5.5 and 6 anteriorly; LSI between 4.5 and 5 posteriorly) with a point by point strategy and an inter-lesion distance &amp;lt;6 mm. According to the HD mapping strategy used to confirm entrance block after first pass PVI, patients were divided in two groups. The HD-LV Group included patients mapped with the HD-LV software and the HD-standard mapping (SM) group included patients which received a conventional PVI validation with a static voltage/activation map. Left PVI was evaluated during distal coronary sinus pacing and right PVI during sinus rhythm. Exit block was also evaluated to confirm bidirectional block. Procedural efficiency parameters were compared between groups. Results Forty-six patients with AF (58% paroxysmal) were prospectively enrolled. Twenty-five patients were included in the HD-LV Group and 21 in the HD-SM Group. PVI was successful in all patients. LV dynamic display analysis was feasible in all patients and allowed a simple and fast validation of right and left PVI, without the necessity of introducing a second catheter into the left atrium. The split screen modality, with a dynamic activation map on the left and a dynamic voltage map on the right, allowed to switch from CS pacing to sinus rhythm without the necessity of a remap. The overall mapping time (27±10 vs 37±14 min, p=0.006), total procedure time (138±33 vs 178±50 min, p=0.006) and fluoroscopy time (14±5.3 vs 23±11 min, p=0.006) were significantly lower in the HD-LV Group. No complication was seen in either group. Conclusions A simplified clinical utilization of LiveView dynamic display with a single transeptal-single HD catheter approach is feasible and efficient after PVI, potentially simplifying the procedural workflow. A real-time dynamic mapping in daily practice may further enhance the clinical benefits of HD mapping during radiofrequency (RF) catheter ablation procedures. Funding Acknowledgement Type of funding sources: None.

Long-Term prognosis of radiofrequency catheter ablation for atrial fibrillation with different subtypes of heart failure in the era of ablation index guidance.

BackgroundThe long-term outcomes of ablation index (AI)-guided radiofrequency catheter ablation (RFCA) on atrial fibrillation (AF) and different subtypes of heart failure (HF) remain unknown. The aim of the study was to evaluate the long-term prognosis of AI-guided RFCA procedures in patients with AF and concomitant HF.MethodsWe retrospectively included consecutive patients with AF and HF who underwent the initial RFCA procedure with AI guidance from March 2018 to June 2021 in our institution. The patients were categorized into two groups: HF with preserved ejection fraction (HFpEF) group and HF with mid-range ejection fraction (HFmrEF) +HF with reduced ejection fraction (HFrEF) group.ResultsA total of 101 patients were included. HFpEF and HFmrEF + HFrEF groups consisted of 71 (70.3%) and 30 patients (29.7%), respectively. During a median follow-up of 32.0 (18.2, 37.6) months, no significant difference was detected in AF recurrence between groups (21.1 vs. 33.3%) after multiple procedures, whereas the incidence of the composite endpoint of all-cause death, thromboembolic events, and HF hospitalization was significantly lower in HFpEF group (9.9 vs. 25.0%, Log-rank p = 0.018). In multivariable analysis, a history of hypertension [hazard ratio (HR) 4.667, 95% confidence interval (CI) 1.433–15.203, p = 0.011], left ventricular ejection fraction (LVEF) < 50% (HR 5.390, 95% CI 1.911–15.203, p = 0.001) and recurrent AF after multiple procedures (HR 7.542, 95% CI 2.355–24.148, p = 0.001) were independently associated with the incidence of the composite endpoint.ConclusionLong-term success could be achieved in 75% of patients with AF and concomitant HF after AI-guided RFCA procedures, irrespective of different HF subtypes. Preserved LVEF was associated with a reduction in the composite endpoint compared with impaired LVEF. Patients with recurrent AF tend to have a poorer prognosis.

Reduced Radiation Exposure Protocol during Computer Tomography of the Left Atrium Prior to Catheter Ablation in Patients with Atrial Fibrillation.

(1) Background: Computer tomography (CT) is an imaging modality used in the pre-planning of radiofrequency catheter ablation (RFA) procedure in patients with cardiac arrhythmias. However, it is associated with a considerable ionizing radiation dose for patients. This study aims to develop and validate low-dose CT scanning protocols of the left atrium (LA) for RFA guidance. (2) Methods: 68 patients scheduled for RFA of atrial fibrillation were sequentially assigned to four groups of ECG-gated scanning protocols, based on the set tube current (TC): Group A (n = 20, TC = 33 mAs), Group B (n = 18, TC = 67 mAs), Group C (n = 10, TC = 135 mAs), and control Group D (n = 20, TC = 600 mAs). We used a 256-row multidetector CT with body weight-dependent tube voltage of 80 kVp (<70 kg), 100 kVp (70–90 kg), and 120 kVp (>90 kg). We evaluated scanning parameters including radiation dose, total scanning procedure time and signal-to-noise ratio (SNR). (3) Results: The average effective radiation dose (ED) was lower in Group A in comparison to Group B, C and D (0.83 (0.76–1.10), 1.55 (1.36–1.67), 2.91 (2.32–2.96) and 9.35 (8.00–10.04) mSv, p < 0.05). The total amount of contrast media was not significantly different between groups. The mean SNR was 6.5 (5.8–7.3), 7.1 (5.7–8.2), 10.8 (10.1–11.3), and 12.2 (9.9–15.7) for Group A, B, C and D, respectively. The comparisons of SNR in group A vs. B and C vs. D were without significant differences. (4) Conclusions: Optimized pre-ablation CT scanning protocols of the LA can reduce an average ED by 88.7%. Three dimensional (3D) models created with the lowest radiation protocol are useful for the integration of electro-anatomic-guided RFA procedures.

Higher serum sST2 is associated with increased left atrial low-voltage areas and atrial fibrillation recurrence in patients undergoing radiofrequency ablation.

To conduct a comprehensive analysis of prospectively measuring the concentration of soluble suppression of tumorigenicity 2 (sST2) to predict left atrial (LA) low-voltage areas (LVAs) and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFA). This was a prospective cohort study. A total of 84 patients, including 54 paroxysmal AF cases and 30 persistent AF cases who underwent RFA, were recruited. Electroanatomical voltage mapping determined the extent of LVAs. The serum level of sST2 was measured by enzyme-linked immunosorbent assay. All patients were followed for 12months after the RFA procedure to verify AF recurrence. The concentration of sST2 measured in the sample was 17.90-198.77pg/mL, and the range of LA LVAs was 0-85.6%. The sST2 level positively correlated with LVAs (r = 0.40; P = 0.005). When comparing the top and bottom quartile, sST2 is significantly associated with LA LVAs (OR = 1.833, 95% CI: 1.582-2.011, P = 0.004). When compared with the 1st quartile group, the multivariable adjusted hazard ratios for AF recurrence after RFA were 1.57 (95% CI: 1.182-1.795) for the 4th quartile group, 1.44 (95% CI: 1.085-1.598) for the 3rd quartile group, and 1.27 (95% CI: 0.954-1.318) for the 2nd quartile group. The AF-free survival rates of patients with 1st quartile and 4th quartile sST2 levels after ablation were 95% and 59.6%, respectively (Log Rank test, P = 0.027). Elevated sST2 levels of AF patients were associated with higher LA LVAs and a significantly increased risk of recurrence. The circulating sST2 concentration might be a pre-diagnostic marker of AF recurrence after RFA.

Severe coronary artery spasm during left atrial appendage closure plus catheter ablation for atrial fibrillation: case presentation

BackgroundLeft atrial appendage closure (LAAC) combined with radiofrequency catheter ablation (RFCA) as a hybrid procedure is commonly performed to treat atrial fibrillation (AF). Although this treatment carries a low risk of coronary artery spasm (CAS), and has never been observed in LAAC procedure, caution still needed to be taken. We presented a case of CAS that occurred in an AF patient during the hybrid procedure.Case presentationThe patient was a 65-year-old man with paroxysmal AF who developed CAS during RFCA and LAAC. In this case, LAAC was performed ahead of RFCA. After atrial septal puncture, the occluder was advanced into left atrium through delivery sheath, and successfully deployed in the LAA. After verifying the assessment of “PASS” criteria, we decided to release the device. However, before releasing the occluder in LAAC, the patient’s blood pressure (BP) fell to 70/45 mmHg with heart rate (HR) drop and ST-segment elevation in II, III, and aVF and reciprocal ST-segment depression in I and aVL. Isotonic sodium chloride load was administered. After 3 min, the BP and HR raised, and ST-segment returned to normal. The occluder was successfully released after the stable condition of the patient. Then, RFCA was sequentially performed. When isolating the right pulmonary veins, the patient’s BP and HR fell again with ST-segment elevation in inferior leads. Spontaneous ventricular tachycardia and fibrillation developed rapidly and defibrillation was performed immediately with success. Coronary angiography revealed the obstruction of the right coronary artery which disappeared completely after intracoronary nitroglycerin injection (1 mg). Under systemic diltiazem infusion, the RFCA procedure was accomplished. After the procedure, the patient recovered without any neurologic deficit, and CAS has never recurred with isosorbide mononitrate treatment during follow-up.ConclusionsCAS is a rare complication associated with AF hybrid procedure. Attention should be paid to this rare but potentially life-threatening complication.

Live integration of comprehensive cardiac CT with electroanatomical mapping in patients with refractory ventricular tachycardia

BackgroundAim of the present study was to verify the feasibility and accuracy of live integration of myocardial fibrosis evaluated at CCT with EAM (electro-anatomical mapping). MethodsWe prospectively enrolled a consecutive cohort of patients with clinical indication to EAM before radiofrequency catheter ablation (RFCA) of refractory ventricular tachycardia (VT) and an absolute contraindication to cardiac magnetic resonance. All patients underwent per protocol CCT for myocardial fibrosis and coronary anatomy evaluation. Diagnostic performance was assessed for myocardial fibrosis evaluation with CCT vs EAM. Live integration feasibility of CCT vs EAM was evaluated for every patients. ResultsA total of 19 patients were included in the present study with 323 myocardial segments analyzed for myocardial fibrosis at CCT. In all patients CCT data were successfully integrated with EAM during RFCA procedure. All patients had myocardial fibrosis correctly identified at CCT vs EAM on a per-patients basis. A diagnostic accuracy on a per-segment basis of 94.1% for detection of any type of myocardial fibrosis at CCT vs EAM was recorded. ConclusionsCCT identification of myocardial fibrosis is feasible and accurate vs EAM in a very selected high risk patients with clinical indication to RFCA of VT and contraindication to CMR.

Abstract 12036: Decreased Sympathetic Innervation Around the Left Atrium After Multiple Catheter Ablation Procedures for Atrial Fibrillation

Introduction: Cardiac sympathetic activity is involved in the initiation and maintenance of atrial fibrillation. A novel technique that evaluates the atrial accumulation of 123I-MIBG may be able to assess the atrial sympathetic innervation. The purpose of this study was to visually evaluate the modification of sympathetic innervation caused by multiple catheter ablations. Methods: The total study cohort comprised 32 patients with atrial fibrillation. 21 patients underwent only one ablation using a balloon catheter (cryoballoon in 10 patients; hot balloon in 11 patients) (group 1), while 11 patients underwent multiple radiofrequency catheter ablation procedures (three procedures in 6 patients; four procedures in 5 patients) (group 2). In all patients, the left atrial sympathetic activity was evaluated using MIBG images obtained using a novel solid-state whole-body scanner (VERITON). For local quantitative evaluation, the site with the strongest discrete MIBG accumulation was automatically recognized by the computer and compared in pre- and post-procedural images. Results: In all patients, the total left atrial MIBG accumulation value after ablation (6.64х10 4 ±1.65х10 4 PROPCNTS) was significantly lower than that before ablation (7.74х10 4 ±2.25х10 4 PROPCNTS, p=0.0289). At the site with the strongest discrete MIBG accumulation, the MIBG accumulation after ablation was decreased in 19 patients, unchanged in 9, increased in 3, and shifted in 1. The total left atrial MIBG accumulation value before ablation was significantly lower in group 2 (5.74х10 4 ±1.40х10 4 PROPCNTS) than group 1 (6.67х10 4 ±1.57х10 4 PROPCNTS, p=0.0485). Conclusions: The MIBG accumulation in the left atrium decreased after catheter ablation. Furthermore, preoperative evaluation revealed a significant decrease in MIBG accumulation after multiple ablation procedures. This suggests that multiple catheter ablation of the left atrium modifies the sympathetic innervation.