Search

Abstract Background Laser balloon (LB) pulmonary vein isolation (PVI) is an established ablation technique for atrial fibrillation (AF). We report long‐term follow‐up and procedural data of LB‐PVI and we compare the first and second LB generation. Methods Patients undergoing LB ablation with first‐ (LB1) or second‐generation LB (LB2) for AF were retrospectively enrolled and divided into two groups. Procedural endpoint was complete PVI. Clinical success was defined as no recurrence of AF/atrial tachycardia after a 90 days blanking period. Results 538 patients were included (age 66 ± 10 years, 58% paroxysmal AF), 427 in LB1 and 111 in LB2. 2079 PVs were targeted and 2073 (99.7%) were successfully isolated; 2027 (97.5%) using solely the LB. Additional touch‐up ablation was limited (46 PVs; 2.2%) with no difference between the groups. Procedural (LB1: 120 ± 33 minutes vs. LB2: 99 ± 22 min; p

Abstract A 69‐year‐old woman with isolated cardiac sarcoidosis was hospitalized for frequent appropriate implantable converter defibrillator therapies for ventricular tachycardia (VT) despite of favorably controlled condition with oral prednisolone. The patient underwent urgent catheter ablation with CARTO 3D mapping system. Although the voltage map, activation map, and propagation map during VT could not visualize the tachycardia circuit, the coherent map clarified entrance and exit sites of the tachycardia circuit with slow or nonconducting (SNO) zones, which seemed like a figure‐of‐eight circuit. Considering the risk of VT termination or acceleration to rapid unstable VT, neither entrainment nor pacing studies were performed. The VT was terminated near the exit site of the isthmus where tiny pre‐systolic potential was detected. Any diastolic potentials could not be detected. This meant that the critical isthmus might be located at the epicardium or deep incite of the left‐ventricular myocardium where the coherent map showed as SNO zones. We should recognize coherent map as artificial that may represent VT circuit as if complete endocardial reentry even if not. The procedural time from mapping to termination of VT was only 22 minutes. The patient has been free from any cardiovascular events after the procedure. Coherent map might be feasible for revealing the critical isthmus of hemodynamically stable VTs without using electrophysiological techniques, including entrainment, pacing study, and voltage map during own beats, and would enable us to achieve successful VT ablation in a short time.

Background: Optimal overlap ratio remains unclear in point-by-point laser balloon (LB) ablation. Objective: This study sought to determine the optimal overlap strategy with target energies on the acute and chronic outcomes in LB pulmonary vein (PV) isolation (PVI). Methods: Consecutive 38 patients (148 PVs) with atrial fibrillation underwent the first-generation LB PVI with the following protocols based on the overlap ratios for each PV anterior/posterior wall: 50%/50% (13 patients [49 PVs], group A), 50%/25% (15 patients [60 PVs], group B), and 25%/25% (10 patients [39 PVs], group C). High energies (240–255 J: 12 W / 20 seconds, 8.5 W / 30 seconds), moderate energies (200–210 J: 10 W / 20 seconds, 7 W / 30 seconds), and low-to-moderate energies (low, 165–170 J: 5.5 W / 30 seconds, 8.5 W / 20 seconds) were targeted for left PV anterior walls, right PV anterior walls, and bilateral PV posterior walls, respectively. First-pass PVI, the other procedure-related data, and atrial tachyarrhythmia recurrences were analyzed. Results: First-pass PVI rate per PV was higher in group A (94%) than in group B (88%) and group C (62%) (P < .001). All PVs were finally isolated. First-pass time, total LB PVI time, complications, and atrial tachyarrhythmia recurrences during a mean follow-up of 11 ± 5 months did not differ between the groups. A few residual gaps after first-pass LB ablations were found for PV anterior walls even in group A and group B. Conclusion: Sufficiently overlapped LB ablation promises a high rate of first-pass PVI without adverse outcomes. High energy could be required for PV anterior walls.

Background: A surface temperature sensor can be used to visualize the effect of hot balloon (HB) catheters. This study evaluated the efficacy and safety of a second-generation HB system with surface temperature monitoring in patients with atrial fibrillation (AF). Methods: Twenty patients (age: 69.6 ± 9.7 years, 11 male participants) who underwent first-time pulmonary vein isolation (PVI) using a second-generation HB were included. For each pulmonary vein (PV), the acute isolation rate and effective therapeutic range of surface temperature were investigated. Results: Eighty-three PVs (including three right middle PVs) were isolated in 20 patients using an HB with a surface temperature sensor. Sixty-eight PVs were isolated using the first application. Fifteen PVs (left superior PV [LSPV], n = 7 [35%]; left inferior PV, n = 2 [10%]; right superior PV, n = 3 [15%]; right inferior PV, n = 3 [15%]) showed early intraoperative reconduction and required second applications. One LSPV required radiofrequency touch-up at the carina. The optimal balloon surface temperature and application time were evaluated, and a median value of 58 °C and integral value of 1000 °C·s were identified from the receiver operating characteristic curve to be useful effective indicators. However, for LSPV, the PV potential of carina or ridge likely often remained and needed to be independently considered. There was no periprocedural complication including severe pulmonary vein stenosis. During the observation period (median: 280 days, interquartile range: 261–318 days), 17 patients (85%) achieved and maintained sinus rhythm. Conclusions: Second-generation HBs with a surface temperature sensor are expected to provide favorable outcomes in AF ablation treatment.

Abstract Heart rate information from a smartwatch can facilitate the diagnosis and treatment of SVT. Benefitting from long‐term HR trends, we performed successful RF catheter ablation of coexisting AVNRT and AVRT.

Abstract Background The ablation index (AI) is reported to be useful for a durable pulmonary vein isolation (PVI). However, there have been no studies investigating the relationship between the power, contact force (CF), AI, and steam pops. Methods Using an in vitro model, ablation energy was delivered until a steam pop occurred and the time to the steam pop and AI when the steam pop occurred were measured. The experiment was performed with a combination of various powers (20, 30, 40, and 50 W) and contact forces (CFs) (10, 30, and 50 g) 20 times for each setting. The analysis consisted of two protocols. The first protocol was a comparison between the ablation power and several parameters under the same CF (10, 30, and 50 g). The second protocol was a comparison between the CF and several parameters under the same power (20, 30, 40, and 50 W). The correlation between the lesion formation and ablation parameters was evaluated. Results The AI value when steam pops occurred varied depending on the ablation settings. All AI median values were

Rett syndrome (RTT) is a neurodevelopmental disorder with X-linked dominant inheritance caused mainly by mutations in the methyl-CpG-binding protein 2 (MECP2) gene. The effects of various Mecp2 mutations have been extensively assessed in mouse models, but none adequately mimic the symptoms and pathological changes of RTT. In this study, we assessed the effects of Mecp2 gene deletion on female rats (Mecp2+/−) and found severe impairments in social behavior [at 8 weeks (w), 12 w, and 23 w of age], motor function [at 16 w and 26 w], and spatial cognition [at 29 w] as well as lower plasma insulin-like growth factor (but not brain-derived neurotrophic factor) and markedly reduced acetylcholine (30%–50%) in multiple brain regions compared to female Mecp2+/+ rats [at 29 w]. Alternatively, changes in brain monoamine levels were relatively small, in contrast to reports on mouse Mecp2 mutants. Female Mecp2-deficient rats express phenotypes resembling RTT and so may provide a robust model for future research on RTT pathobiology and treatment.

The body surface area (BSA) of an organism is an important parameter for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying a constant by the power of the body weight (BW). Recently, the use of miniature pigs in non-clinical studies for medical drugs or devices has gradually been increasing. However, verification of their BSA is not as yet sufficient. In this study, we measured the BSAs of 40 laboratory miniature pigs (11 males and 9 females of Göttingen minipig and 14 males and 6 females of Nippon Institute for Biological Science [NIBS] miniature pig) by analyzing computed tomography (CT) images, since measurements using a CT scanner were expected to more precisely determine BSA than classical measuring techniques. The measurement results showed the BSAs of the 20 Göttingen minipigs to range from 0.4358 to 0.8356 m² (the working BW range: 12.7-37.0 kg) and 20 NIBS miniature pigs to range from 0.2906 to 0.8675 m² (the working BW range: 7.9-41.5 kg). Since accuracy and reproducibility were confirmed by measuring the surface area of an acrylic cuboid, we concluded the measurement method employed in this study to be very reliable. We propose the following estimating formula for BSA of laboratory miniature pigs: 100 × BSA [m²] = 7.98 × BW [kg]2/3. [ABSTRACT FROM AUTHOR]