Predictors and outcomes of tricuspid regurgitation improvement after radiofrequency catheter ablation for persistent atrial fibrillation.

INTRODUCTION: Little has been reported on the predictors and outcomes of improvement of tricuspid regurgitation (TR) after radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (AF). METHODS: We enrolled 141 patients with persistent AF and moderate or severe TR assessed by transthoracic echocardiography (TTE) who underwent an initial RFCA between February 2015 and August 2021. These patients underwent follow-up TTE at 12 months after the RFCA, and were categorized into two groups based on the improvement (defined as at least one-grade improvement of TR) and non-improvement of TR: IM group and Non-IM group, respectively. We compared the patient characteristics, ablation procedures, and recurrences after the RFCA between the two groups. In addition, we examined the major event (defined as admission for heart failure or all-cause death) more than 12 months after the RFCA. RESULTS: IM group consisted of 90 patients (64%). A multivariate analysis revealed that age <71 years old and absence of late recurrence (LR, defined as recurrence of atrial tachyarrhythmia between 3 and 12 months after the RFCA) were independently associated with the improvement of TR after the RFCA. Furthermore, IM group had the higher incidence of major event-free survival than Non-IM group. CONCLUSIONS: Relatively young age and absence of LR were good predictors of improvement of TR after the RFCA for persistent AF. In addition, the improvement of TR was related to better clinical outcomes.

The correlation between local impedance drop and catheter contact in clinical pulmonary vein isolation use.

INTRODUCTION: Local impedance (LI) drop during radiofrequency (RF) application is monitored to assess the lesion formation. Recently, a novel ablation catheter has been introduced to clinical setting, which is capable of monitoring LI and catheter contact parameters including contact force (CF) and contact angle (CA). This study aimed to clarify the correlation between LI drop and catheter contact parameters. METHODS AND RESULTS: This prospective study included 15 paroxysmal atrial fibrillation (AF) patients who underwent initial pulmonary vein isolation (PVI). First-pass encircling point-by-point PV ablation was performed by using a 4.5-mm irrigated ablation catheter, with monitoring LI, CF, and CA. RF energy was applied for 30 s at each site with 30 W. Stable ablation points were analyzed to examine the correlation between LI drop and catheter contact parameters. Among 903 ablation points, 499 stable ablation points (55.2%) were analyzed. CA showed good correlation with LI drop (ρ = 0.418, p < .001). Maximum CF, minimum CF, average CF, and initial CF all showed weak correlation with LI drop (ρ = 0.201, p < .001; ρ = 0.224, p < .001; ρ = 0.258, p < .001; and ρ = 0.212, p < .001, respectively). Multivariate analysis demonstrated that CA was an independent factor of LI drop among the catheter contact parameters (ß = 0.139, 95% CI = 0.111-0.167, p < .001). The LI drop in the blocked segments was significantly higher than that in the electrical conduction gap segments (27.3 ± 9.8 vs. 19.6 ± 6.4 Ω, p < .001) CONCLUSION: In clinical PVI use, both CF and CA were correlated with LI drop. More parallel CA could induce higher LI drop, which may lead to effective lesion formation.

Impact of very early recurrence of atrial fibrillation after cryoballoon ablation.

BACKGROUND: Although much has been discussed about the early recurrence of atrial fibrillation (ERAF) after cryoballoon ablation (CBA), the clinical impact of very early recurrence of atrial fibrillation (VERAF) after CBA remains unclear. This study aimed to investigate the impact of VERAF after CBA. METHODS: We enrolled 236 consecutive patients who underwent an initial CBA for paroxysmal atrial fibrillation between February 2017 and December 2020 in our hospital. These patients were categorized into three groups: VERAF group who experienced an initial recurrence of atrial tachyarrhythmia within 48 h after CBA, late-ERAF (LERAF) group who experienced an initial recurrence of atrial tachyarrhythmia between 48 h and 3 months after CBA, and non-ERAF (NERAF) group who did not experience a recurrence of atrial tachyarrhythmia within 3 months after CBA. We investigated the late recurrence of AF (LRAF, defined as recurrence of atrial tachyarrhythmia more than 3 months after CBA), and the incidence of non-pulmonary vein (PV) triggers in the patients who experienced a repeat ablation procedure due to LRAF. RESULTS: VERAF group had a higher incidence of freedom from LRAF than LERAF group (p = 0.032) and a lower incidence of freedom from LRAF than NERAF group (p = 0.002). Moreover, VERAF group had the highest incidence of non-PV triggers at repeat ablation procedure among the three groups (p = 0.003). CONCLUSIONS: While ERAF was a predictor of LRAF, VERAF was less related to LRAF among the patients with ERAF after CBA. Furthermore, VERAF might be associated with non-PV triggers.

Insights into Current Veterinary Pharmaceutics for Companion Animals in Japan: A Study Based on Data from the Veterinary Drug Side Effect Database.

In veterinary medicine, various drugs are used on a daily basis. Using inappropriate medications poses health hazards to companion animals and humans; thus, assessing adverse events in veterinary medicine has great social significance but remains an untapped area of research. In this study, to promote the appropriate use of veterinary drugs and clarify common pharmaceutical issues in Japanese veterinary medicine, we analyzed information in the Veterinary Drug Side Effects Database (National Veterinary Assay Laboratory of the Ministry of Agriculture, Forestry and Fisheries, Japan). We found that the number of reports has been increasing annually, including those on high-risk drugs, molecular-targeted drugs, and antibody-based drugs. The details of the reports were similar to those from the United States, including the misadministration of veterinary drugs to humans, improper drug management, and re-administering drugs with a history of side effects. Furthermore, 46.50% of all reports mentioned the administration of one or more drugs, with the highest number of concomitant drugs being 10. In addition, 37.78% of all reports described the use of drugs in manners deviating from the intended use indicated in the package insert. Therefore, to avoid adverse events, pharmacists may have to be involved in dispensing and aseptically preparing veterinary medicines and providing drug information and medication guidance. To optimize pharmacotherapy for ill companion animals, "veterinary pharmacy" and "veterinary medicine pharmacy" must be developed in line with clinical situations in Japan, while considering knowledge from countries that are advanced in terms of veterinary medicine.

Impact of cryoballoon contact angle and acute myocardial injury on pulmonary vein reconnection.

At present, it remains unclear whether the effect on cryoinjury can be strongly exerted by contact of the balloon with the pulmonary vein (PV) ostium. The present study included 204 paroxysmal atrial fibrillation (PAF) patients who underwent an initial pulmonary vein isolation (PVI) using a cryoballoon from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. The total balloon contact angle was measured from the equator line (sum of the angles of the upper side and bottom side in all PVs) under fluoroscopic imaging. The patients were stratified into three tertile groups according to the total balloon contact angle. We evaluated the relationship between the total balloon contact angle and clinical outcomes, including the value of acute myocardial injury marker (high-sensitive cardiac troponin I [hs-TnI]), arrhythmia recurrence, and PV reconnections in the repeated ablation. The total balloon contact angle was significantly associated with the hs-TnI value among the tertile groups (p < 0.001) and a multiple regression analysis showed that the total balloon contact angle significantly correlated with the hs-TnI value (standardized beta-coefficient = 0.572, p < 0.001). The balloon contact angle in PVs with PV reconnections was significantly lower than in those without (p = 0.044), while no significant differences in the recurrence of atrial fibrillation among the tertile groups were observed in the enrolled patients. The total balloon contact angle was significantly associated with the acute myocardial injury marker, hs-TnI. The total balloon contact angle was significantly associated with PV reconnections after cryoballoon ablation in patients who underwent a repeat ablation.

Impact of radiofrequency catheter ablation for atrial fibrillation in patients with left atrial enlargement.

Little has been reported on the impact of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in patients with left atrial enlargement (LAE). A total of 706 patients underwent an initial RFCA for AF between September 2014 and September 2019 in our hospital. These patients were categorized into two groups according to the pre-procedural left atrial diameter (LAD) measured by transthoracic echocardiography (TTE): LAE group with LAD ≥ 50 mm and non-LAE group with LAD < 50 mm. We compared the patient characteristics, ablation procedures, and late recurrence of AF (LRAF, defined as a recurrence of atrial tachyarrhythmia between 3 and 12 months after the RFCA) between the two groups. In addition, we performed follow-up TTE at 12 months after RFCA and investigated the factors associated with left atrium (LA) reverse remodeling in each group. LAE group and non-LAE group consisted of 155 and 551 patients, respectively. There were no significant differences in ablation procedures, procedure-related complications, and the incidence of LRAF between the two groups. Furthermore, non-PAF was identified as an independent predictor of LA reverse remodeling in LAE group by multiple regression analysis (P = 0.020). RFCA might be an effective and safe procedure even in patients with LAD ≥ 50 mm, using the contemporary 3D-guided mapping and ablation technologies. Moreover, RFCA can lead to LA reverse remodeling in 1 year if they have non-PAF before ablation.

Acute myocardial injury after radiofrequency catheter ablation: impact on pulmonary vein reconnection and relevant factors.

Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) causes myocardial injury and induces high-sensitive cardiac troponin I (hs-TnI) release into the systemic circulation. Several factors are considered to be associated with myocardial injury after ablation, but few studies showed the relationship between the value of myocardial injury marker after the RFCA and relevant factors. AF patients who underwent primary RFCA were enrolled from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. The relationship between hs-TnI after the RFCA and PV reconnection (PVR) was evaluated. The impact of relevant factors, including baseline patient characteristics, detail of procedure on myocardial injury was investigated. This study included 407 patients (median age was 71 years, the ratio of female was 30.7%). Late arrhythmia recurrence was observed in 111 patients (27.3%) and 66 patients were underwent repeated ablation. PVR was observed in 33 patients (50.0%). The hs-TnI level was significantly lower in the patients with PVR than those without PVR (1.150 ng/ml vs 1.921 ng/ml, p = 0.040). Paroxysmal AF and age were significantly associated with acute myocardial injury after the RFCA (standardized beta coefficient = 0.206 and p < 0.001, standardized beta coefficient = - 0.114 and p = 0.043, respectively). The hs-TnI after RFCA was significantly higher in PAF patients than PerAF (p < 0.001), even if application number and total application time were taken into consideration. Acute myocardial injury after RFCA was significantly lower in the patients with PVR than those without PVR. Age and AF type were significantly and strongly associated with acute myocardial injury after the RFCA.

Suitable Dose of Long-Term Tolvaptan to Reduce Heart Failure Rehospitalizations.

The short-term effectiveness of tolvaptan (TLV) for heart failure (HF) has been established, but the long-term effects are controversial. We investigated HF patients who could not discontinue both loop diuretics and TLV at discharge from AURORA (Acute Heart Failure Registry in Osaka Rosai Hospital). We compared the following factors at discharge between the RH group, consisting of patients with rehospitalizations due to worsening HF within 1 year after discharge (RH group), and non-RH group: age, gender, blood pressure, history of HF admission, electrocardiogram and echocardiographic parameters, atherosclerotic risk factors, laboratory data, and medications. Furthermore, we compared the effects of long-term low-dose TLV (≤ 7.5 mg/day) and high-dose TLV on HF rehospitalizations. The RH group consisted of 81 patients (58.7%). A multivariate analysis revealed that a history of HF admission and the TLV dose were independently and significantly associated with 1-year HF rehospitalizations. A receiver operating characteristic curve revealed that 7.5 mg of TLV was a suitable cutoff value for 1-year HF rehospitalizations. The Kaplan-Meier curves demonstrated that the HF rehospitalization free ratio was significantly higher in the low-dose TLV group (≤ 7.5 mg/day) than in high-dose TLV group over 1 year.In conclusion, the TLV dose, in addition to a history of HF admission, was associated with 1-year HF rehospitalizations in diuretic-dependent HF patients. In these patients, long-term low-dose TLV (≤ 7.5 mg/day) may be favorable for reducing HF rehospitalizations.

Novel Endovascular Therapy, AGET, for In-Stent Occlusions in Iliac and Femoropopliteal Arteries.

Catheter-directed intra-arterial thrombolysis (CDT) is useful for not only patients with acute limb ischemia but also those with chronic total occlusions (CTOs) of the lower extremity arteries. However, it is difficult to determine whether CTO lesions have significant thrombi, which can be treated by CDT, or not in a clinical setting. Angioscopy can accurately detect thrombi. We investigated the clinical impact of angioscopy guided endovascular therapy following thrombolysis (AGET) for in-stent occlusions (ISOs) in iliac or femoropopliteal arteries.We performed AGET in 7 patients with ISOs whose occlusion duration was less than 1 year. We performed angioscopy to evaluate the area of the thrombi after a successful wire crossing of an ISO lesion. In addition, we performed biopsies of ISO lesions to confirm whether the angioscopic findings coincided with the histopathological findings at 20 sites. We selectively performed a continuous infusion of urokinase using a fountain infusion catheter for ISO lesions. The next day, we evaluated the lesion flow and performed intervention only at the plaque stenosis site if necessary.AGET could achieve TIMI 3 flow in all patients, and preserved a 1-year patency in 5 patients (71.4%). The angioscopic findings of thrombi and plaque perfectly coincided with the histopathological findings.In conclusion, this new endovascular therapy technique, AGET, was observed to be feasible and safe for iliac or femoropopliteal artery ISO lesions.

Electrophysiological identification of superior vena cava: Novel insight into slow conduction or conduction block.

INTRODUCTION: It has not been clarified how to identify the electrophysiological junction between right atrium (RA) and superior vena cava (SVC). The aim of this study was to identify the electrophysiological RA-SVC junction according to slow conduction or conduction bock and to examine the electrophysiological SVC isolation procedure. METHODS: Seventy-three consecutive atrial fibrillation patients who underwent SVC mapping using a CARTO 3 system were enrolled in this study. Slow conduction or conduction block between the RA and SVC was identified by adjusting the lower threshold criteria of the early meets late function and was described as a white line. The SVC isolation was performed along the white line and with pacing maneuvers to confirm direct SVC capture. RESULTS: Activation mapping (1296 ± 631 points) was obtained in 66 patients (90%) in 4.6 ± 1.8 min. Slow conduction or conduction block was observed in all patients. The threshold for detecting slow conduction or conduction block was 24 ± 8 ms. The location of the electrophysiological RA-SVC junction was higher in the anterior portion (anterior-septal, anterior, and anterior-lateral) than in the posterior portion (posterior-septal, posterior, and posterior-lateral) (-2.3 ± 6.2 mm vs. 7.1 ± 6.3 mm, p < .001). The SVC isolation at the electrophysiological RA-SVC junction was successful in all patients without any injury to the sinus node function. Asymptomatic phrenic nerve injury was observed in three patients (4.5%). CONCLUSION: In all patients, the electrophysiological RA-SVC junction determined by slow conduction or conduction block was identified and the electrophysiological SVC isolation was performed successfully and safely.

Effect of the Balloon Size on Lesion Formation During Visually Guided Laser Balloon Ablation in an In Vitro Model.

BACKGROUND: It is unclear whether balloon size can influence lesion formation. The aim of this study was to evaluate the impact of balloon size on lesion formation during laser balloon procedures in an in vitro model.Methods and Results:Laser energy was applied to chicken muscle using a first generation laser balloon. Laser ablation was performed with 2 different balloon sizes (18 mm and 32 mm) using 2 different power settings (12 W/20 s and 8.5 W/20 s) on the chicken muscle. The lesion characteristics, including maximum lesion depth, maximum lesion diameter, surface diameter and depth at maximum diameter, were compared between the 18-mm and 32-mm balloon groups at 12 W/20 s and 8.5 W/20 s, respectively. We created 40 lesions using laser energy at 12 W/20 s and 80 lesions at 8.5 W/20 s. At both power settings, the maximum lesion depth and the depth at the maximum diameter were larger in the 18-mm than in the 32-mm balloon group. At both power settings, the maximum lesion diameter and the surface diameter were smaller in the 18-mm than in the 32-mm balloon group. CONCLUSIONS: The balloon size could affect the lesion formation during laser balloon ablation. The lesion with the larger balloon size was wider and shallower than the lesion with the smaller balloon size.

Predictors of improvement of left ventricular systolic function after catheter ablation of persistent atrial fibrillation in patients with heart failure with reduced ejection fraction.

Although several studies have suggested that catheter ablation (CA) of atrial fibrillation (AF) can improve left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction (HFrEF), the predictor of improvement of LVEF is unclear. A total of 401 patients with persistent AF underwent an initial CA between September 2014 and October 2019 in our hospital. Among them, we analyzed consecutive patients with moderately or severely reduced LVEF (< 50%) measured by transthoracic echocardiography (TTE) within 2 months before CA and underwent follow-up TTE during sinus rhythm at 6 months or more after CA. These patients were categorized into two groups: improve group (I group) with the absolute improvement of LVEF ≥ 10% at follow-up TTE, and non- improve group (NI group) with the absolute improvement of LVEF < 10% at follow-up TTE. We compared patient characteristics, ablation procedures, and clinical outcomes between the two groups. 81 patients were analyzed, and I group consisted of 48 patients (59%). In the univariate analysis, absence of ischemic cardiomyopathy, left ventricular end-diastolic diameter (LVEDD), and absence of recurrence of AF between 3 and 6 months after CA were associated with improvement of LVEF. A receiver operating characteristics analysis determined the suitable cut-off value for LVEDD was 53 mm (sensitivity: 62.2%, specificity: 86.2%, area under curve: 0.762). A multivariate analysis showed that LVEDD < 53 mm was independently associated with improvement of LVEF (odds ratio 2.58, 95% confidence interval 1.29-6.12; P = 0.021). In conclusion, LVEDD < 53 mm might be an independent predictor of improvement of LVEF after CA of persistent AF in HFrEF patients.

Underweight Is Associated with Poor Prognosis in Heart Failure with Preserved Ejection Fraction.

The obesity paradox states higher body mass index (BMI) is associated with better outcomes than normal weight in patients with heart failure with preserved ejection fraction (HFpEF). However, underweight was defined by BMI < 18.5 kg/m2, and results have been inconclusive, in part due to small number of participants. The number of underweight patients with HFpEF is higher in Asian than in Western countries. In this study, we aim to determine the prognostic impact of underweight in patients with HFpEF in Asian population.We enrolled 846 consecutive patients from the PURSUIT-HFpEF registry. We then divided them into three groups by BMI, namely, underweight (BMI < 18.5 kg/m2), normal weight (18.5 ≤ BMI < 23), and overweight (23 ≤ BMI). The underweight group consisted of 187 patients (22%). Over a mean follow-up of 407 days, 105 deaths were reported as all-cause mortality. On multivariable Cox analysis, the underweight group was determined to be significantly associated with higher risk of all-cause mortality than the normal and overweight groups (Hazard ratios [HR]: 2.33; 95% confidence intervals [CI]: 1.45-3.75, P < 0.001; HR: 3.54; 95% CI: 1.99-6.29, P < 0.001, respectively), after adjustment for age, sex, vital signs, and comorbidities.Underweight is a useful predictor of poor prognosis in patients with HFpEF in Asian population.

Comparison of myocardial injury and inflammation after pulmonary vein isolation for paroxysmal atrial fibrillation between radiofrequency catheter ablation and cryoballoon ablation.

BACKGROUNDS: Several studies have shown the serum high sensitive cardiac troponin I (hs-TnI) a biomarker of myocardium injury, and C-reactive protein (CRP), a biomarker of inflammation, are associated with worse cardiovascular outcomes. We evaluated the relationship between the hs-TnI level in patients with paroxysmal atrial fibrillation (PAF) after pulmonary vein isolation (PVI) and atrial fibrillation (AF) recurrence. METHODS AND RESULTS: We enrolled 263 consecutive PAF patients who underwent PVI from May 2017 to April 2018. We investigated the difference in the relationship between the myocardial injury marker (serum hs-TnI), inflammatory marker (CRP, white blood cell) at 36 to 48 hours after the PVI, and early or late recurrence of AF (ERAF; <3 months and LRAF; from 3 months to 1 year) between the radiofrequency ablation group (R group) and cryoballoon ablation group (C group). The R group consisted of 147 patients and the C groups consisted of 116 patients. The serum hs-TnI level in R group was significantly lower than in the C group (2.33 vs 5.08 ng/mL; P < .001), while the CRP was significantly higher in the R group than C group (2.02 vs 1.10 mg/dL; P < .001). The incidences of an ERAF/LRAF were similar between the two groups. CONCLUSION: Cryoballoon ablation may cause more myocardial injury than radiofrequency catheter ablation, on the contrary, radiofrequency catheter ablation, may cause more inflammation than cryoballoon ablation. However, these phenomena may not affect the recurrence of AF after the PVI in patient with PAF.

Clinical experience of uninterrupted oral anticoagulants during atrial fibrillation ablation in elderly patients: a comparison with non-elderly patients.

It is unclear whether uninterrupted oral anticoagulants (OACs) are acceptable in elderly patients as compared to non-elderly patients. This study aimed to assess the clinical impact of an uninterrupted OAC strategy during atrial fibrillation (AF) ablation in elderly patients. We enrolled 439 consecutive patients who underwent AF ablation with an uninterrupted OAC strategy at our institute. The incidence of bleeding and thromboembolic complications during the AF ablation or within 4 weeks after and the anticoagulation status during the AF ablation were compared between the elderly (age ≧ 75, n = 144) and non-elderly groups (n = 295). There were 22 bleeding complications in the elderly group and 31 in the non-elderly group (15% vs. 11%, p = 0.162) and 3 major bleeding complications in the elderly group and 2 in the non-elderly group (2% vs. 0.7%, p = 0.336). Thromboembolic events were observed in 1 patient in the elderly group and 2 in the non-elderly group (0.7% vs. 0.7%, p = 1.000). The ACT at the end of the procedure was longer in the elderly group than in the non-elderly group (350 s vs. 341 s, p = 0.007) and the proportion of a prolonged ACT of > 400 s (27% vs. 18%, p = 0.046) was more frequent in the elderly group than non-elderly group. A propensity score matched population excluding the age and body weight, revealed that the anticoagulation status during AF ablation was comparable between the two groups. Thus, in the patients undergoing AF ablation with uninterrupted OAC strategy, bleeding complications in elderly patients were similar to those in non-elderly patients. The anticoagulation status during the procedure in elderly patients was more prolonged than that in non-elderly patients.

A case of a "pseudo jump-up phenomenon" caused by retrograde ventricular-His prolongation.

A 35-year-old woman was referred for treatment of a supraventricular tachycardia. The tachycardia was diagnosed as a slow-fast form of atrioventricular nodal reentrant tachycardia. Radiofrequency ablation targeting the antegrade slow pathway was performed at the posterior septum of the right atrium. After the radiofrequency ablation, ventricular extrastimulus pacing was performed to assess the retrograde slow pathway, which was suggested before the ablation. The prolongation of the VA interval with a 10 ms decrease in the S2 pacing interval was 60 ms and retrograde dual pathways were suspected. However, the HA interval did not change and a prolongation of the VA interval was caused by the prolongation of the VH interval and no additional ablation was required.

Different Neoatherosclerosis Patterns in Drug-Eluting- and Bare-Metal Stent Restenosis　- Optical Coherence Tomography Study.

BACKGROUND: There are few reports about the differences between drug-eluting stents (DES) and bare metal stents (BMS) in neoatherosclerosis associated with in-stent restenosis (ISR), so we compared the frequency and characteristics of neoatherosclerosis with ISR evaluated by optical coherence tomography (OCT) in the present study. Methods and Results: Between March 2009 and November 2016, 98 consecutive patients with ISR who underwent diagnostic OCT were enrolled: 34 patients had a BMS, 34 had a 1st-generation DES, and 30 had a 2nd-generation DES. Neoatherosclerosis was defined as a lipid neointima (including a thin-cap fibroatheroma [TCFA] neointima, defined as a fibroatheroma with a fibrous cap <65 µm) or calcified neointima. As a result, lipid neointima, TCFA neointima and calcified neointima were detected in 39.8%, 14.3%, and 5.1%, respectively, of all patients. The frequency of neoatherosclerosis was significantly greater with DES than BMS (48.4% vs. 23.5%, P=0.018). The minimum fibrous cap thickness was significantly thicker with DES than BMS (110.3±41.1 µm vs. 62.5±17.1 µm, P<0.001). In addition, longitudinal extension of neoatherosclerosis in the stented segment was less with DES than BMS (20.2±15.1% vs. 71.8±27.1%, respectively, P=0.001). CONCLUSIONS: OCT imaging demonstrated that neoatherosclerosis with ISR was more frequent with DES than BMS and its pattern exhibited a more focal and thick fibrous cap as compared with BMS.

Postmortem late phase histopathology after pulmonary vein isolation using a cryoballoon: A case report.

We report the autopsy case of 68-year-old woman who received cryoballoon (CB) ablation for paroxysmal atrial fibrillation 7 months before death. Both macroscopic and microscopic findings revealed no thrombus formation around pulmonary veins. Previous experimental studies have shown the lower risk of thrombus formation in CB ablation as compared to radiofrequency ablation. Our findings in the human autopsy case may support this merit of CB ablation. To confirm this benefit of CB ablation, further studies regarding histopathology of CB ablation should be performed.

Successful ablation for premature ventricular contraction originating from moderator band of morphologic right ventricle in congenitally corrected transposition of great arteries.

A 54-year-old man with congenitally corrected transposition of great arteries (CCTGA) was referred to our hospital for palpitation. 24-hour Holter ECG showed frequent premature ventricular contraction (PVC) and we performed catheter ablation for this PVC. Pace-mapping was performed in morphologic right ventricle (RV) by transaortic approach. Perfect pace-map was achieved in morphologic RV midpart lateral and ablation at this site could eliminate the clinical PVC. After the ablation, by integrating ablation site and 3D mapping, we diagnosed that the clinical PVC was originated from the moderator band (MB) of morphologic RV.