DNA Image Cytometry for Screening the Carcinogenetic Risk of Oral Potential Malignant Disorders.

Background: Oral Submucosal Fibrosis (OSF) and Oral Leukoplakia (OLK) are well-known oral potentially malignant disorders, and cases of Oral Submucosal Fibrosis concomitant Oral Leukoplakia (OSF+OLK) are now being reported clinically. DNA image cytometry is an objective and non-invasive method for monitoring the risk of precancerous lesions in the oral cavity. Methods: A total of 111 patients with clinically characterized oral mucosal lesions underwent simultaneous and independent histopathological and DNA imaging cytometry assessments. Clinical data were also collected for each patient. Results: The frequency of DNA content abnormality was higher in the tongue than in other oral sites (P = 0.003) for OLK. The frequency of DNA content abnormality was higher in the tongue than in other oral sites (P = 0.035) for OSF+OLK. The differences of DNA content abnormality in age, sex, dietary habit, smoking, and alcohol intake were not observed in OLK and OSF+OLK. The study indicates an association between DNA content abnormality and pathological examination in OSF+OLK ( χ2 test, P = 0.007). OLK showed higher sensitivity and specificity than OSF, while the sensitivity and specificity of OSF+OLK are higher than OLK only and OSF only. Conclusion: DNA image cytometry can be utilized as an adjunctive device for the initial detection of oral potentially malignant disorders that require further clinical management.

Soluble PILRα: A novel plasma biomarker for atrial fibrillation progression and recurrence after catheter ablation.

BACKGROUND: We aimed to identify plasma biomarkers of atrial fibrillation (AF) progression and recurrence after catheter ablation. METHODS: Using AF gene profiling data from GEO database, a weighted gene co-expression network analysis (WGCNA) was conducted to determine the most significant module and hub genes associated with AF. Subsequently, 318 consecutively admitted patients who had undergone radiofrequency catheter ablation were enrolled in this study. RESULTS: WGCNA results revealed that paired immunoglobulin-like type 2 receptor alpha (PILRA) was the only black module gene highly correlated with clinical traits. Plasma soluble PILRα (sPILRα) levels were elevated in patients with AF and significantly elevated in patients with persistent versus paroxysmal AF (4.64 ± 2.74 vs. 3.04 ± 1.56 ng/mL, p < 0.001). Elevated sPILRα level was an independent risk factor for AF progression even after adjusting for traditional factors (adjusted odds ratio: 3.06, 95 % confidence interval [CI]: 1.88-5.27, p < 0.001) and AF recurrence after catheter ablation in patients with persistent AF (adjusted hazards ratio: 4.41, 95 % CI: 1.22-15.92, p = 0.023). CONCLUSIONS: WGCNA screening of GEO microarray gene profiling data showed PILRA expression levels to be correlated with AF progression and recurrence after catheter ablation in patients with persistent AF.

Plasma myeloperoxidase: association with atrial fibrillation progression and recurrence after catheter ablation.

Background: Myeloperoxidase (MPO), released by activated neutrophils, is significantly increased in atrial fibrillation (AF). MPO may play a role in the progression of atrial fibrillation and further involved in AF recurrence after catheter ablation. We compared plasma MPO levels in paroxysmal and persistent AF and explored their role in AF recurrence after catheter ablation. Methods: Plasma MPO levels were measured in consecutive patients with paroxysmal AF (n = 225) and persistent AF (n = 106). Samples of patients were collected from the femoral vein during catheter ablation and all patients included were followed up after catheter ablation. Results: Plasma MPO levels increased from paroxysmal AF to persistent AF patients (56.31 [40.33-73.51] vs. 64.11 [48.65-81.11] ng/ml, p < 0.001). MPO significantly correlated with left atrium volume (LAV) and there existed a significant interaction between the two in relation to AF recurrence (p for interaction <0.05). During a median follow-up of 14 months, 28 patients with paroxysmal AF (12.44%) and 27 patients with persistent AF (25.47%) presented with recurrence after catheter ablation. The percentage of recurrence increased stepwise with increasing tertiles of MPO levels in both paroxysmal AF and persistent AF. MPO levels remained independently associated with AF recurrence after adjusting for potential confounding variables. Conclusion: MPO levels were higher in persistent AF than in paroxysmal AF and MPO was positively correlated with LAV in AF. Elevated MPO levels may predispose a switch in AF phenotype and AF recurrence after catheter ablation.

Different electrophysiological characteristics of cavo-tricuspid isthmus dependent atrial flutter guided by robotic magnetic navigation in patients with and without prior cardiac surgery.

BACKGROUD: Cavo- tricuspid isthmus dependent atrial flutter (CTI- AFL) is a common atrial arrhythmia in patients with prior cardiac surgery (postsurgical AFL) and without prior cardiac surgery (nonsurgical AFL). However, there is only limited data regarding the eletrophysiological differences between the CTI- AFL in the postsurgical patients and the nonsurgical patients. HYPOTHESIS: We aimed to investigate the differences in clinical and electrophysiological characteristics between the postsurgical group and nonsurgical group and to evaluate the acute and long-term outcomes after ablation guided by robotic magnetic navigation (RMN) in both the groups. Methods Fourty-two consecutive patients with nonsurgical AFL and 21 with postsurgical AFL were retrospectively analyzed in our center. Electrocardiographic (ECG) analysis and three-dimensional electrophysiological study were performed in all the patients. RESULTS: The results revealed that only 55.6% of postsurgical patients with proven counterclockwise (CCW) AFL presented with a typical ECG suggesting this mechanism. In contrast, 86.1% of nonsurgical patients demonstrated a typical ECG pattern for CCW AFL. In addition, we employed a reverse "U-curve" to facilitate radiofrequency delivery when ablating near the inferior vena cava ostium in the present study. Compared with the nonsurgical group, electroanatomical mapping showed the mean AFL cycle length was significantly longer (253.3 ± 40.4 vs. 234.1 ± 24.2 ms, p = 0.03) and the right atrium volume was larger (114.8 ± 26.0 vs. 97.5 ± 19.1 mL, p = 0.004) in the postsurgical group. Additionally, the procedural time (75.9 ± 21.3 vs. 61.6 ± 26.6 minutes, p = 0.03) and ablation time (53.0 ± 21.4 vs. 36.7 ± 25.6 minutes, p = 0.02) are much longer in the postsurgical group. However, the navigation index in the postsurgical group was significantly smaller (0.35 ± 0.08 vs. 0.43 ± 0.13, p = 0.01). Moreover, the acute and long-term success rates were comparable between the two groups. CONCLUSIONS: Catheter ablation of CTI-AFL with and without prior cardiac surgery guided by RMN are associated with high acute and long-term success rates, despite the procedural and ablation times are much longer in the postsurgical patients. However, ECG characteristics of the tachycardia may be misleading as they are more often atypical in patients after cardiac surgery.

Initial experience of a novel method for electrical isolation of the superior vena cava using cryoballoon in patients with atrial fibrillation.

BACKGROUND: Damage to the sinus node (SN) has been described as a potential complication of superior vena cava (SVC) isolation. There have been reports of permanent SN injury requiring pacemaker implantation during isolation of the SVC. HYPOTHESIS: It is safe and effective to isolate SVC with the second-generation 28-mm cryoballoon by using a novel method. METHODS: Forty-three patients (including six redo cases) with SVC-related atrial fibrillation (AF) from a consecutive series of 650 patients who underwent cryoballoon ablation were included. After pulmonary vein isolation was achieved, if the SVC trigger was identified, the SVC was electrically isolated using the cryoballoon. First, the cryoballoon was inflated in the right atrium (RA) and advanced towards the SVC-RA junction. After total occlusion was confirmed by dye injection with total retention of contrast in the SVC, the SVC-RA junction was determined. Next, the cryoballoon was deflated, advanced into SVC, then reinflated, and pulled back gently. The equatorial band of the cryoballoon was then set slightly (4.32 ± 0.71 mm) above the SVC-RA junction for isolation of the SVC. RESULTS: Real-time SVC potential was observed in all patients during ablation. The mean time to isolation was 24.5 ± 10.7 s. The SVC was successfully isolated in all patients. The mean number of freeze cycles was 2.5 ± 1.4 per patient, and the mean ablation time was 99.8 ± 22.7 s. A transient phrenic nerve (PN) injury occurred in one patient (2.33%). There were no SN injuries. Freedom from AF rates at 6 and 12 months was 97.7% and 93.0%, respectively. CONCLUSIONS: This novel method for SVC isolation using the cryoballoon is safe and feasible when the SVC driver during AF is determined and could avoid SN injury. PN function should still be carefully monitored during an SVC isolation procedure.

Prognostic Implications of Left Atrial Spontaneous Echo Contrast with Catheter Ablation of Nonvalvular Atrial Fibrillation Patients with Left Atrial Dilation.

Background: Left atrial spontaneous echo contrast (LASEC) can be detected by transesophageal echocardiography (TEE) before the catheter ablation of atrial fibrillation (AF), especially in patients with left atrial (LA) dilation. Whether LASEC has prognostic value in predicting the procedure outcomes in patients with an enlarged atrium is unknown. The prognostic implications of LASEC with the catheter ablation of AF patients with LA dilation will be evaluated in this study. Methods: AF patients scheduled to undergo catheter ablation in Ruijin Hospital, Shanghai, China, between January 2018 and June 2020 were screened for this prospective study. All patients underwent TEE before the procedure. Patients with a left atrial diameter (LAD; 45 mm ≤ LAD < 50 mm) and left atrial volume (LAV ≥ 120 mL) were enrolled in this study. The endpoint was AF/atrial tachycardia (AT) recurrence-free survival following a 3-month blanking period after the catheter ablation. All patients were followed up for 18 months. Results: This study included 123 AF patients, who were divided into the LASEC (n = 73) and no LASEC (n = 50) groups. Baseline patient characteristics were similar in the two groups. At the end of 18 months of follow-up, AF/AT recurrence-free survival was achieved in 33 (45.2%) and 34 (68.0%) patients in the LASEC and no LASEC groups, respectively (p = 0.013). In survival analysis, the LASEC group was also associated with a poor outcome of catheter ablation (log-rank test, p = 0.011; Cox regression, p = 0.015, HR = 2.058, 95%CI = 1.151−3.679). Meanwhile, during the follow-up AF/AT recurrence was observed in 30 (57.7%) and 15 (71.4%) cases in the mild and severe SEC groups, respectively. Ischemic stroke occurred in two patients in the LASEC group. Conclusions: LASEC could be a predictor of the recurrence of AF/AT after catheter ablation in AF patients with LA dilation. The higher the degree of LASEC, the worse the prognosis.

Application of 5-aminolevulinic acid-mediated Waterlase-assisted photodynamic therapy in the treatment of oral leukoplakia.

Photodynamic therapy (PDT) is an alternative microinvasive approach with satisfying results in the treatment of oral leukoplakia (OL). PDT combined with laser irradiation shows promise, safety and efficacy in treating OL. The efficacy of waterlase (YSGG) combined with PDT was studied by brush and tissue biopsy. Seventy-one patients with histologically diagnosed OL were enrolled, including patients with mild to moderate dysplasia, severe dysplasia and various dysplastic tissues. Patients were evaluated at baseline (t0), the end of treatment (t1) and 1 year later (t2). At t1, PDT showed a significant therapeutic effect on OL with mild to moderate dysplasia. Clinical and histological examinations revealed 60 cases (84.51%) of complete remission and 11 cases (15.49%) of partial remission. On brush biopsy, all PDT-treated patients showed reduced aneuploidy and normal histological findings. Unfortunately, at t2, 9 patients relapsed with OL, which may be related to continued smoking and betel nut chewing. At t2, 5 patients developed new severe epithelial dysplasia and even carcinoma in situ in other areas, mostly the tongue. ALA-mediated PDT combined with YSGG is effective in treating OL, particularly that with mild to moderate dysplasia. However, severe dysplasia may present undesirable effects, and the mechanism remains to be further investigated. ALA-mediated PDT combined with YSGG provides a new method for OL treatment.

Long-term outcomes of a time to isolation - based strategy for cryoballoon ablation compared to radiofrequency ablation in patients with symptomatic paroxysmal atrial fibrillation.

BACKGROUND: Cryoballoon ablation (CBA) is one of the most commonly used technologies designed for pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF), although the dosing of CBA remains controversial. We evaluated the long-term efficacy and safety of a novel individualized strategy of CBA compared to radiofrequency ablation (RFA) for patients with PAF. METHODS: In this observational study, symptomatic patients with drug-refractory paroxysmal AF were prospectively consented and enrolled in four centers, being assigned either to the CBA or RFA arm for ablation. In the CBA group, we used a time to isolation (TTI) - based dosing protocol. The primary endpoint was the recurrence of atrial arrhythmia >30 s following a 90-day blanking period. The secondary endpoint was procedure-related complications and procedure parameters. RESULTS: A total of 500 patients were recruited in either the CBA group (n = 247) or the RFA group (n = 253) between January 2017 and July 2018. After a median follow-up of 778 days, the atrial tachyarrhythmia-free survival was 71.7% in the CBA group and 67.0% in the RFA group. CBA and RFA displayed similar major or minor complication occurrence, while the former had a significantly shorter procedure duration (82.5 min vs. 141.1 min, p < .001) and left atrial dwell time (60.1 min vs. 109.9 min, p < .001) but longer fluoroscopy exposure (13.8 min vs. 8.1 min, p < .001). CONCLUSION: Compared to RFA, our TTI-based CBA dosing protocol showed comparable efficacy and safety, with a significantly reduced procedure duration in patients with PAF.

Association of Circulating IgE and CML Levels with In-Stent Restenosis in Type 2 Diabetic Patients with Stable Coronary Artery Disease.

Background: We investigated whether serum levels of immunoglobin (Ig) E and Nε-carboxymethyl-lysine (CML) are related to in-stent restenosis (ISR) in patients with stable coronary artery disease and type 2 diabetes mellitus (T2DM). Methods: Serum levels of IgE and CML were measured in 196 ISR patients and 220 non-ISR patients with stable angina and T2DM who received angiographic follow-up 12 months after percutaneous coronary intervention (PCI) with third-generation drug-eluting stent (DES) implantation for de novo lesions. Multivariate logistic regression analysis was performed to assess the association between IgE or CML and ISR. Results: Both IgE and CML levels were higher in patients with ISR compared with non-ISR patients (IgE: 187.10 (63.75−489.65) vs. 80.25 (30.65−202.50), p < 0.001; CML: 203.26 (164.50−266.84) vs. 174.26 (130.85−215.56), p < 0.001). The rate of ISR increased stepwise with increasing tertiles of IgE and CML levels (p for all trends < 0.001), and IgE correlated significantly with CML. After adjusting for potential confounders, IgE and CML levels remained independently associated with ISR. Moreover, IgE and CML levels improved the predictive capability of traditional risk factors for ISR, and there existed an interaction between IgE and CML in relation to ISR (p for interaction < 0.01). Conclusion: Elevated circulating IgE and CML levels confer an increased risk for ISR after DES-based PCI in type 2 diabetic patients with stable coronary artery disease.

The feasibility of using remote magnetic navigation system as the primary technological training tool for novice cardiac electrophysiology operators in the catheter ablation of left-sided accessory pathway.

BACKGROUND: For novice operators, mastering catheter ablation of left-sided accessory pathway (LSAP) in a short duration of time without compromising efficacy and safety remains a challenge. In this study an attempt to shorten the learning curve by using robotics via a remote magnetic navigation (RMN) system was performed. METHODS: Novice physician fellows without prior catheter ablation experience initiated their process of learning LSAP ablation using the Niobe™ RMN system. Their procedure parameters were recorded and compared with experienced operators using RMN and manual catheter navigation (MCN). RESULTS: Novice operators quickly shortened the total procedure time after their first five procedures. In subsequent procedures, no significant difference in procedure time, fluoroscopy exposure or ablation time was observed between novice and experienced RMN operators. When compared to MCN operators, novice operators avoided excessive radiation exposure beginning with their first RMN procedure, while lower fluoroscopy doses were noted after five procedures. It was observed that procedure parameters did not differ significantly according to LSAP location. CONCLUSION: The RMN system is a practical and easy to use tool for novice electrophysiology operators to quickly master LSAP ablation, without compromising efficacy or safety. Additionally, when compared to MCN it also protects the operators and patients from excessive radiation exposure during the procedure.

Comparison of the Mid-Term Outcomes of Robotic Magnetic Navigation-Guided Radiofrequency Ablation versus Cryoballoon Ablation for Persistent Atrial Fibrillation.

Introduction: Currently, numerous ablation techniques are available for atrial fibrillation (AF), in addition to manual radio frequency ablation. The aim of this prospective, non-randomized concurrent controlled trial was to compare the mid-term efficacy and procedural outcomes of persistent AF (PerAF) using cryoballoon (CB) and robotic magnetic navigation (RMN). Methods: Two hundred PerAF patients were assigned, in a 1:1 ratio, to undergo catheter ablation using RMN (RMN group) or CB (CB group). The primary endpoint was freedom from AF recurrence following a 3-month period after the index ablation. The secondary endpoint was peri-procedural outcomes, including the total procedure time, left atrial procedure time, fluoroscopy time, and fluoroscopy dose. The Two-step cluster analysis was used to determine the efficacy of RMN and CB between the different groups. The Cox proportional hazard model and restricted cubic spline were used to determine predictors for AF recurrence. Results: At the mean follow-up of 28.1 ± 9.7 months, the primary endpoint was achieved in 71 PerAF patients in the RMN group and in 62 PerAF patients in the CB group (71% vs. 62%, p = 0.158). Compared with CB, RMN-guided ablation led to a longer procedure time (p < 0.001), but with less radiation (p < 0.001). Cluster analysis returned two clusters of patients and RMN was favorable for one cluster (p = 0.037), in which more patients presented with diabetes mellitus and smaller left atria. Conclusions: For patients with PerAF, CB is generally equivalent to RMN-guided ablation with regard to overall efficacy. RMN-guided ablation could be favorable in specific patient populations presenting with diabetes mellitus and smaller left atria.

Utilization of steerable sheath improves the efficiency of atrial fibrillation ablation guided by robotic magnetic navigation compared with fixed-curve sheath.

BACKGROUND: The objective of this study was to assess the impact of steerable sheaths compared with fixed-curve sheaths on the procedural outcomes of atrial fibrillation (AF) ablation guided by robotic magnetic navigation (RMN). METHODS AND RESULTS: In this retrospective case-control study, 110 patients scheduled for AF catheter ablation were enrolled and divided into two groups. Fifty-five patients (paroxysmal, 70%) were treated with RMN-guided ablation utilizing a steerable sheath and another 55 patients (paroxysmal, 70%) were ablated with RMN using a fixed-curve sheath. Clinical characteristics were similar between the two groups. Compared with the fixed-curve sheath group, the steerable sheath group procedure time (111.9 ± 25.2 vs. 90.4 ± 20.7 min, p < .001) and radiofrequency (RF) time (35.9 ± 9.0 vs. 30.5 ± 7.4 min, p < .001) were significantly shortened. Additionally, the navigation index was significantly improved (0.41 ± 0.06 vs. 0.48 ± 0.08, p < .001) in the steerable sheath group. By employing a large catheter loop for targeting the right pulmonary veins (PVs), the steerable sheath group significantly reduced the RF delivery time (15.0 ± 3.0 vs. 12.0 ± 2.1 min, p < .001) during right-side PV isolation (PVI). However, total fluoroscopy time was similar between the two groups (5.6 ± 2.6 vs. 5.0 ± 2.0 min, p > .05). Acute PVI success rates were similar between the two groups. No major or minor complications occurred in either group. CONCLUSION: Appropriate utilization of steerable sheath technology can improve the efficiency of AF ablation guided by RMN, primarily by reducing the total procedure and RF delivery times of right-side PVI without compromising safety.

Differences in D-dimer blood concentration in atrial fibrillation patients with left atrial thrombus or severe left atrial spontaneous echo contrast.

PURPOSE: Severe left atrial spontaneous echo contrast (SLASEC) is considered the prior stage to thrombosis and a high-risk factor for thrombotic events. Studies have suggested an effect of D-dimer blood concentration on exclusion of left atrial thrombus (LAT), but it remains unclear whether D-dimer concentrations differ between atrial fibrillation (AF) patients with SLASEC or LAT. METHODS: Nonvalvular AF patients scheduled to undergo catheter ablation or cardioversion in Shanghai Ruijin Hospital between January 2017 and July 2020 were screened for this prospective study. All patients underwent transesophageal echocardiography (TEE) to detect SLASEC or LAT. D-dimer concentrations were measured at the time of TEE. Clinical data including CHA2DS2-VASc score were evaluated. Major complications with thromboembolism in the SLASEC group were followed up at least 6 months after therapy. RESULTS: Among 920 consecutively enrolled nonvalvular AF patients, 30 patients with SEC grade 0, 35 patients with SLASEC, and 22 patients with LAT were included. D-dimer concentration and CHA2DS2-VASc score were significantly lower in the SLASEC group compared with the LAT group (D-dimer, 0.26±0.13 vs. 0.86±0.9 mg/L, P<0.05; CHA2DS2-VASc score, 2.3±0.9 vs. 3.1±1.5, P=0.02). The cut-off value for D-dimer concentration (0.285 mg/L) had sensitivity of 77.3% and specificity of 80.0% for prediction of LAT. D-dimer concentration showed a decreasing trend with a significant difference (0.42±0.22 vs. 0.33±0.18 mg/L, P=0.03) for 9 patients in the LAT group after complete thrombus resolution by anticoagulation treatment. No major or fatal bleeding, ischemic stroke, or systemic thromboembolism events occurred in the SLASEC group during the 6-month follow-up. CONCLUSIONS: This study demonstrated a significantly lower D-dimer concentration and CHA2DS2-VASc score in AF patients with SLASEC than in those with LAT. The D-dimer cut-off value (0.285 mg/L) can be used as an effective reference index to distinguish the pre-thrombotic state of LAT from LAT. D-dimer blood concentration may be a predictor of LAT thrombolysis.

Plasma protein profiling analysis in patients with atrial fibrillation before and after three different ablation techniques.

Background: There are controversies on the pathophysiological alteration in patients with atrial fibrillation (AF) undergoing pulmonary vein isolation using different energy sources. Objectives: We evaluated the changes in plasma proteins in acute phase post-ablation in patients receiving cryoballoon ablation, radiofrequency balloon ablation, or radiofrequency ablation. Methods: Blood samples from eight healthy controls and 24 patients with AF were taken on the day of admission, day 1, and day 2 post-ablation and analyzed by the Olink proximity extension assay. Proteins were identified and performed with enrichment analysis. Protein-protein interaction network and module analysis were conducted using Cytoscape software. Results: Of 181 proteins, 42 proteins in the cryoballoon group, 46 proteins in the radiofrequency balloon group, and 43 proteins in the radiofrequency group significantly changed after ablation. Most of the proteins altered significantly on the first day after ablation. Altered proteins were mainly involved in cytokine-cytokine receptor interaction. Both balloon-based ablations showed a similar shift toward enhancing cell communication and regulation of signaling while inhibiting neutrophil chemotaxis. However, radiofrequency ablation presented a different trend. Seed proteins, including osteopontin, interleukin-6, interleukin-10, C-C motif ligand 8, and matrix metalloproteinase-1, were identified. More significant proteins associated with hemorrhage and coagulation were selected in balloon-based ablations by machine learning. Conclusion: Plasma protein response after three different ablations in patients with AF mainly occurred on the first day. Radiofrequency balloon ablation shared similar alteration in protein profile as cryoballoon ablation compared with radiofrequency ablation, suggesting that lesion size rather than energy source is the determinant in pathophysiological responses to the ablation.

Remote magnetic-guided ablation for three origins of idiopathic ventricular arrhythmias with right bundle branch block and superior axis.

BACKGROUND: Idiopathic ventricular arrhythmias (IVAs) with right bundle branch block (RBBB) and superior axis commonly originate from posterior mitral annulus (PMA), the left ventricular (LV) posterior fascicle (LPF), and the LV posterior papillary muscles (PPM). HYPOTHESIS: Remote magnetic navigation (RMN)-guided ablation might be safe and effective for these three origins of IVAs. METHODS: Thirty consecutive IVA patients with RBBB and superior axis (11 MPA-IVAs, 11 LPF-IVAs, and 8 PPM-IVAs) were included in this study. Electrical mapping and ablation with RMN were performed in the LV through a trans-septal approach. Navigation index, defined as the ratio of total radiofrequency (RF) time and the time from first burn to last burn, was used to determine the efficiency of RMN-guided ablation. RESULTS: The overall acute success rate was achieved in 93% (PMA, 100%; LPF, 91%; PPM, 88%; p > 0.05). No complication occurred in this study. The procedure time of PPM-IVAs group was 34 and 14 min longer when compared with MPA-IVAs and LPF-IVAs group, respectively, without an increase of X-ray time. The mean navigation index was 0.45 ± 0.20. The PPM-IVAs group had an underperforming navigation index value (0.29 ± 0.11) (p < 0.01), as longer RF time was required in the PPM-IVAs group. CONCLUSIONS: RMN-guided ablation can achieve a high acute success rate for IVAs with RBBB and superior axis. The lower navigation index for PPM-IVAs indicated that increasing the RF time and improving the catheter contact should be considered when using RMN.

Cryoballoon ablation for extrapulmonary vein targets.

PURPOSE OF REVIEW: Cryoballoon catheter can create large and contiguous lesions with stable contact during ablation. It has proven to be well tolerated and effective in pulmonary vein isolation. But atrial arrhythmias, including atrial fibrillation, atrial tachycardia, and atrial flutter (AFL), also relate to many extrapulmonary vein targets. It is necessary to understand the current evidence for the use of cryoballoon ablation for targets outside of pulmonary veins. RECENT FINDINGS: Studies have shown that the cryoballoon ablation can be used in extrapulmonary vein area, including left atrium roof, left atrial appendages, posterior left atrial wall, mitral isthmus, and right atrial appendage. The results indicate cryoballoon ablation is an effective and well-tolerated treatment option for the atrial arrhythmias in these locations outside of pulmonary vein when clinical necessary. SUMMARY: The cryoballoon ablation can safely and effectively perform contiguous linear lesions, structure isolations, and local ablation for targets outside of the pulmonary veins.

Novel strategy of remote magnetic navigation-guided ablation for ventricular arrhythmias from right ventricle outflow tract.

The optimized strategy to further increase the success rate of ablation for ventricular arrhythmias (VAs) from the right ventricular outflow tract (RVOT) is challenging. Recent studies have shown that the pulmonary sinus cusp (PSC) region may be the origin of certain RVOT VAs. We evaluated the efficacy of preferential ablation below the pulmonary valve (PV) and alternated radiofrequency delivery in the PSC using remote magnetic navigation (RMN). Sixty-five (65) consecutive patients experiencing VAs with RVOT-like appearance were included in this study. Mapping and ablation were preferentially performed below the PV. Ablation in the PSC would only be attempted when intensified ablation below the PV could not eliminate VAs. Finally, if ablation in the RVOT region failed, the aortic sinus cusp (ASC) would be mapped. Sixty-one (61) of 65 (93.8%) patients achieved procedural success. Except 7 cases of which the VAs were ablated in the ASC, the rest 54 VAs were thought to be originate from the RVOT region. Fifty (50) of 54 VAs were successfully ablated below the PV, and in the presence of a local special signal in the bipolar electrogram a more aggressive ablation was required. Subsequent ablation in the PSC with assistance of the RMN system achieved success in the remaining 4 patients. No complications occurred in this study. Our strategy of using RMN-guided ablation below the PV for VAs of RVOT origin was proved to be effective. PSC mapping and ablation using a magnetic catheter may provide the optimal strategy for treating these types of arrhythmias.

Glucose fluctuations promote vascular BK channels dysfunction via PKCα/NF-κB/MuRF1 signaling.

Glucose fluctuations may contribute to large conductance calcium activated potassium (BK) channel dysfunction. However, the underlying mechanisms remain elusive. The aim of this study was to investigate the molecular mechanisms involved in BK channel dysfunction as a result of glucose fluctuations. A rat diabetic model was established through the injection of streptozotocin. Glucose fluctuations in diabetic rats were induced via consumption and starvation. Rat coronary arteries were isolated and coronary vascular tensions were measured after three weeks. Rat coronary artery smooth muscle cells were isolated and whole-cell BK channel currents were recorded using a patch clamp technique. Human coronary artery smooth muscle cells in vitro were used to explore the underlying mechanisms. After incubation with iberiotoxin (IBTX), the Δ tensions (% Max) of rat coronary arteries in the controlled diabetes mellitus (C-DM), the uncontrolled DM (U-DM) and the DM with glucose fluctuation (GF-DM) groups were found to be 84.46 ± 5.75, 61.89 ± 10.20 and 14.77 ± 5.90, respectively (P < .05), while the current densities of the BK channels in the three groups were 43.09 ± 4.35 pA/pF, 34.23 ± 6.07 pA/pF and 17.87 ± 4.33 pA/pF, respectively (P < .05). The Δ tensions (% Max) of rat coronary arteries after applying IBTX in the GF-DM rats injected with 0.9% sodium chloride (NaCl) (GF-DM + NaCl) and the GF-DM rats injected with N-acetyl-L-cysteine (NAC) (GF-DM + NAC) groups were found to be 8.86 ± 1.09 and 48.90 ± 10.85, respectively (P < .05). Excessive oxidative stress and the activation of protein kinase C (PKC) α and nuclear factor (NF)-κB induced by glucose fluctuations promoted the decrease of BK-ß1 expression, while the inhibition of reactive oxygen species (ROS), PKCα, NF-κB and muscle ring finger protein 1 (MuRF1) reversed this effect. Glucose fluctuations aggravate BK channel dysfunction via the ROS overproduction and the PKCα/NF-κB/MuRF1 signaling pathway.

Procedural outcomes and learning curve of cardiac arrhythmias catheter ablation using remote magnetic navigation: Experience from a large-scale single-center study.

BACKGROUND: Remote magnetic navigation (RMN)-guided ablation has become an inspiring method of catheter ablation for tachyarrhythmias. HYPOTHESIS: Data from a large-scale single center may provide further insight into the safety of and the learning curve for RMN-guided ablation. METHODS: A total of 1003 catheter ablation procedures using RMN for conditions including supraventricular ventricular tachycardia, atrial tachyarrhythmias, and premature ventricular contraction/ventricular tachycardia (PVC/VT) were retrospectively analyzed from an ablation registry. Procedural outcomes, including procedure time, mapping time, X-ray time, and RF time, were assessed. The complications were classified into two categories: major and minor. A subanalysis was used to illustrate the learning curve of RMN-guided ablation by assessing procedure time and total X-ray time of 502 atrial fibrillation (AF) ablation procedures. RESULTS: Among these procedures, 556 (55.4%) were AF and 290 (28.9%) were PVC/VT. Electrical pulmonary vein isolation was achieved in 99.0% of AF procedures, and acute success reached 90.3% in PVC/VT procedures. The overall complication rate was 0.5%. In the subanalysis of AF procedures, the overall procedure time and X-ray time of procedures were short (125.9 ± 54.6 and 5.3 ± 3.9 minutes, respectively) and proceeded to decrease from the initial 30 procedures to about 300 procedures, where the learning curve reached plateau, demonstrating maximum procedure efficiency. CONCLUSIONS: RMN-guided ablation is safe, as verified by very low overall complication rate and reduced X-ray time. In our study, even the first AF procedures had a relatively low procedure time and total X-ray time, and procedure efficiency improved during the learning curve.