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Background: Patients with subcutaneous implantable cardioverter‐defibrillators (S‐ICDs) experience an oversensing episode (OS) more frequently than those with transvenous ICDs. However, no established electrocardiography (ECG) parameters can accurately detect an OS. This study aimed to evaluate the incidence of an OS in real‐world clinical practice and the association of synthesized 18‐lead ECG (syn18‐ECG) parameters with an OS. Methods: We retrospectively included 21 consecutive patients who underwent S‐ICD implantation and collected syn18‐ECG parameters. We placed the generator in a deep posterior position and defined an OS as an inappropriate charging episode caused by cardiac or noncardiac signals. A SMART pass filter and two tachyarrhythmia zones were programed. Results: The most frequent underlying heart disease was Brugada/J wave syndrome (n = 7). During a median follow‐up period of 1188 days, an OS was observed in six patients (28.6%). The QRS amplitude in synthesized V7 lead (synV7) was significantly lower in the OS group than in the non‐OS group (0.59 ± 0.17 vs. 0.91 ± 0.35 mV, p = 0.019). The optimal cutoff value of synV7 QRS amplitude was 0.61 mV, with a sensitivity of 80.0% and a specificity of 83.7% for predicting an OS. Univariate logistic analysis showed that a synV7 QRS amplitude of <0.61 mV was only associated with an OS (odd ratio, 20.0; 95% confidence interval, 1.66–241.72; p = 0.018). Conclusions: In patients with S‐ICDs, an OS was not a rare complication during long‐term follow‐up. A low synV7 QRS amplitude was associated with a high OS incidence. [ABSTRACT FROM AUTHOR]

Background: Fractionated atrial potential (FAP) during sinus rhythm (SR) may be a new target for ablation of atrial fibrillation (AF). However, the effects of the direction of activation and premature atrial contraction (PAC) on FAP is unknown. Therefore, we examined the impact of anisotropic conduction and PAC on the distribution and areas of FAP. Methods: FAP map in the left atrium was created in 40 patients with AF before ablation. The distribution and areas of FAP were compared during SR, distal coronary sinus (CS) pacing (S1) and extrastimulus (S2), and paced PAC after SR. FAP was defined as a potential with four or more fragmented deflections. Results: FAPs during SR were found in the right and mid‐anterior walls and septum in most patients. During S1 compared to SR, FAPs significantly decreased in the right and mid‐anterior walls, appendage, septum, and right inferior wall, while significantly increased in the lateral wall. During S2 compared to S1, FAPs significantly increased in the mid anterior and right and mid posterior walls. During PAC compared to SR, FAPs significantly decreased in the right and mid anterior walls and roof, while significantly increased in the left anterior, left inferior and lateral walls. A rotational activation pattern at the FAP area during CS pacing was observed in 12 patients (30%), mostly in the left inferior wall. Conclusions: The distribution and areas of FAP vary with anisotropic conduction and extrastimulus. Therefore, FAP should be evaluated not only during SR but also during extrastimulus from the distal CS. [ABSTRACT FROM AUTHOR]

Background: Deltoid muscle detachment and atrophy have been reported to occur after shoulder surgery. Purpose: To investigate the 2-year changes in deltoid muscle structure and function after arthroscopic rotator cuff repair (ARCR) using magnetic resonance imaging (MRI) and electrophysical examination. Study Design: Case series; Level of evidence, 4. Methods: A total of 72 patients (72 shoulders) who underwent ARCR between 2015 and 2020 were enrolled. Whole deltoid muscle volume and regional (anterior, lateral, and posterior) muscle thicknesses were determined on T2-weighted MRI scans of both shoulders taken preoperatively and at 1, 3, 6, 12, and 24 months postoperatively, and their correlations with compound muscle action potentials (CMAPs), shoulder abduction muscle strength, and Constant scores were investigated. Comparison between groups was performed using paired or Student t tests, and the relationship between deltoid muscle volume and various factors was determined using Pearson correlation analysis. Results: The volume of the deltoid muscle on the affected side decreased from 44,369 ± 12,371 mm3 preoperatively to 38,139 ± 10,615 mm3 at 1 month postoperatively (P <.05), representing a 14% decrease. The deltoid muscle volume of the contralateral side also significantly decreased during the same time frame, from 43,278 ± 12,248 to 40,273 ± 11,464 mm3 (P <.05), representing a 7% decrease at 1 month postoperatively. Subsequently, the deltoid muscle volume on both sides recovered to preoperative levels at 12 months and was maintained at 24 months. Only the thickness of the anterior part of the deltoid was markedly decreased, from 13.9 ± 3.7 mm preoperatively to 12.0 ± 3.2 mm at 1 month postoperatively (P <.05), representing a 14% reduction. The CMAP amplitude showed a significant decrease at 1 month postoperatively; however, no significant difference was observed after 12 months when compared with the preoperative values or the values on the contralateral side. Positive correlations were found between deltoid muscle volume and CMAP amplitude at 24 months as well as between deltoid muscle volume and shoulder abduction muscle strength (R 2 = 0.698; P <.05) and Constant score (R 2 = 0.133; P <.05). Conclusion: Our study demonstrated that the early structural and functional decline of the deltoid muscle after ARCR was fully recovered within 1 year, confirming that this procedure does not negatively affect the deltoid muscle. [ABSTRACT FROM AUTHOR]

Background: Mapping of atypical atrial arrythmias arising in the left atrium is often challenging. The Local Activation Time (LAT) Histogram, a new function of the 3D color mapping system CARTO version 7, may help improve identification of atrial tachycardia circuits. We aimed to assess the effectiveness of the LAT Histogram for identification of left atrial tachycardia circuits. Methods: This retrospective study compared 25 consecutive cases of left atrial tachycardia that were treated before use of LAT Histogram (unused group) and 25 consecutive cases that were treated after introduction of LAT Histogram (used group) at Nagano Chuo Hospital. We evaluated whether we could identify the circuit of left atrial tachycardia from the electrophysiology lab data during ablation and the CARTO system data and whether we could perform effective ablation. Results: Door‐to‐door time, skin‐to‐skin time, and fluoroscopy time (p ≤.011) were all shorter in the LAT Histogram used group versus unused group, while mapping analysis times were longer in the used group (p ≤.019). A significantly greater number of cases in the LAT Histogram used compared with the unused group had ablation for entrance or exit points (19 vs. 10 cases; p =.001 for first map). Ablation resulted in a return to sinus rhythm and changed cycle length at the first mapping in 20 cases (80%) in the LAT Histogram unused group and in 24 cases (96%) in the used group. Conclusions: LAT Histogram may provide a simple and effective method to identify entrance and exit locations in left atrial tachycardia. [ABSTRACT FROM AUTHOR]

The prevalence of underweight among young women is a serious international health issue. However, the evidence on how being underweight negatively affects brain health and cognition is still unclear. This study investigated the association between underweight status, academic performance, and neurocognitive control in young Japanese women using a cross-sectional design. We analyzed the academic performance of female undergraduates, comparing underweight and healthy-weight groups (n = 43; age 18–23 years, M = 21.1, SD = 1.3) based on their grade point average (GPA). We also analyzed their error-related negativity (ERN), an electrophysiological measure that potentially reflects academic performance, during an arrowhead version of the flanker task to assess cognitive control of action monitoring. Participants with a low body mass index were found to have lower GPAs. Furthermore, the underweight students exhibited smaller ERN amplitudes, which indicates decreased cognitive control in action monitoring. These findings suggest that a healthy weight status is essential for effective cognitive functioning and academic success in young adult women, among whom being underweight is a serious health problem. [ABSTRACT FROM AUTHOR]

Background: The precise details of atrial activation around the triangle of Koch (ToK) remain unknown. We evaluated the relationship between the atrial-activation pattern around the ToK and success sites for slow-pathway (SP) modification ablation in slowfast atrioventricular reentrant tachycardia (AVNRT). Methods: Thirty patients with slow-fast AVNRT who underwent successful ablation were enrolled. Atrial activation around the ToK during sinus rhythm was investigated using ultra-high-density mapping pre-ablation. The relationships among features of atrial-activation pattern and success sites were examined. Results: Of 30 patients (22 cryoablation; 8 radiofrequency ablation), 26 patients had a collision site of two wavefronts of delayed atrial activation within ToK, indicating a success site. The activation-search function of Lumipoint software, which highlights only atrial activation with a spatiotemporal consistency, showed non-highlighted area on the tricuspid-annulus side of ToK. In 23 of the patients, a spiky potential was recorded at that collision site outside the Lumipoint-highlighted area. Fifteen cryoablation patients with a success site coincident with a collision site outside the Lumipoint-highlighted area had significantly more frequent disappearances of SP after initial cryoablation (46.7% vs. 0%, p = .029), fewer cryoablations (3.7 ± 1.8 vs. 5.3 ± 1.3, p = .045), and shorter procedure times (170 ± 57 vs. 228 ± 91 min, p = .082) compared to the seven cryoablation patients without such sites. Four patients had transient AV block by ablation inside the Lumipoint-highlighted area with fractionated signals, but no patient developed permanent AV block or recurrence post-procedure (median follow-up: 375 days). Conclusions: SP modification ablation at the collision site of atrial activation of the tricuspid-annulus side along with a spiky potential could provide a better outcome. [ABSTRACT FROM AUTHOR]

Background: Although pulmonary vein isolation (PVI) for atrial fibrillation (AF) utilizing radiofrequency (RF) applications with a very high-power and short-duration (vHPSD) has shortened the procedure time, the determinants of pulmonary vein (PV) gaps in the first-pass PVI and acute PV reconnections are unclear. Methods: An extensive encircling PVI was performed with the QDOT MICRO catheter with a vHPSD (90 W-4 s) in 30 patients with AF (19 men, 64 ± 10 years). The association of the PV gap sites (first-pass PVI failure, acute PV reconnections [spontaneous reconnections or dormant conduction provoked by adenosine triphosphate] or both) with the left atrial (LA) wall thickness and LA bipolar voltage on the PVI line and ablation-related parameters were assessed. Results: PV gaps were observed in 29 (6%) of 480 segments (16 segments per patient) in 17 patients (56%). The PV gaps were associated with the LA wall thickness, bipolar voltage, and the number of RF points (LA wall thickness, 2.5 ± 0.5 vs. 1.9 ± 0.4 mm, p < .001; bipolar voltage, 2.59 ± 1.62 vs. 1.34 ± 1.14 mV, p < .001; RF points, 6 ± 2 vs. 4 ± 2, p = .008) but were not with the other ablation-related parameters. Receiver operating characteristic curves yielded that an LA wall thickness ≥2.3 mm and bipolar voltage ≥2.40 mV were determinants of PV gaps with an area under the curve of 0.82 and 0.73, respectively. Conclusions: The LA voltage and wall thickness on the PV-encircling ablation line were highly associated with PV gaps using the 90 W/4 s-vHPSD ablation. [ABSTRACT FROM AUTHOR]

Introduction: Electrophysiological characteristics of epicardial connections (ECs) in atria and pulmonary veins (PVs) are unclear despite their important contributions to atrial fibrillation (AF). Unidirectional conduction associated with source‐sink mismatch can occur in ECs due to their fine fibers with abrupt changes in orientation. We detailed the prevalence and electrophysiological characteristics of unidirectional conduction in the atria and investigated its association with the clinical manifestation of AF. Methods: This study retrospectively reviewed electrophysiological studies and radiofrequency catheter ablation in 261 consecutive patients with AF. Results: Unidirectional conduction was observed during ablation encircling the PVs in eight (3.1%) patients, and all occurred in the suspected (N = 4) or definitively (N = 4) recognized ECs. These ECs included three intercaval bundles, four septopulmonary bundles, and one Marshall bundle, and were first manifested in a second procedure in 6 (75%) patients. The unidirectional property was from PV to atrium (exit conduction) in all intercaval bundles and three septopulmonary bundles, and from atrium to PV (entrance conduction) in the remaining two bundles. Intercaval bundles acted as a limb of bi‐atrial macro‐reentrant tachycardia (50%, three of the six including previous cases). Ablation of the exit outside the PVs, including the right atrium, eliminated ECs in three (38%) patients. All patients remain free from arrhythmia recurrence after a mean 13‐month follow‐up. Conclusion: A unidirectional conduction property was closely associated with the EC, as estimated by histological findings. Recognition of this fact by electrophysiologists may help to clarify mechanisms for AF and atrial tachycardia and guide the creation of efficient and safe ablation lesion sets. [ABSTRACT FROM AUTHOR]

Background and Aims: Pathogenic variants of HSPB1, the gene encoding the small heat shock protein 27, have been reported to cause autosomal dominant distal hereditary motor neuropathy (dHMN) type II and autosomal dominant Charcot–Marie‐Tooth (CMT) disease with minimal sensory involvement (CMT2F). This study aimed to describe the clinical features of patients in a family with late‐onset dHMN carrying the Pro39Leu variant of HSPB1. Methods: Whole‐exome sequence analysis identified a heterozygous pathogenic variant (Pro39Leu) of HSPB1 in the proband. The presence of the HSPB1 Pro39Leu variant in two affected individuals was confirmed using direct nucleotide sequence analysis. Results: Both patients exhibited distal muscle weakness with lower extremity predominance and no obvious sensory deficits, leading to a clinical diagnosis of late‐onset dHMN. Nerve conduction studies (NCSs) revealed a subclinical complication of sensory disturbance in one of the patients. The clinical and electrophysiological findings of patients with the HSPB1 Pro39Leu variant in this study and previous reports are summarized. Interpretation: This study suggests that the clinical spectrum of patients carrying HSPB1 Pro39Leu variants, especially the disease onset, might be broader than expected, and HSPB1 variants should be considered in patients diagnosed with late‐onset dHMN. Furthermore, patients with dHMN may have concomitant sensory deficits that should be evaluated using NCSs. [ABSTRACT FROM AUTHOR]

Background: Interatrial conduction time (IACT) prolongs in fibrotic left atrium. We tested the hypothesis that IACT is related to left atrial low voltage area (LVA) and predicts the recurrence after single atrial fibrillation (AF) ablation. Methods: One hundred sixty‐four consecutive AF patients (79 non‐paroxysmal) who underwent initial ablation in our institute were analyzed. IACT and LVA were defined as interval from the onset of P‐wave to the basal left atrial appendage (P‐LAA) activation, and area with bipolar electrogram < 0.5 mV covering over 5% of the total left atrial surface area during sinus rhythm, respectively. Pulmonary vein antrum isolation, non‐PV foci ablation, and atrial tachycardia (AT) ablation were performed without substrate modification. Results: LVA was frequently identified in patients with prolonged P‐LAA ≥ 84 ms (n = 28) compared with patients with P‐LAA < 84 ms (n = 136). Patients with P‐LAA ≥ 84 ms were older (71 ± 10 vs. 65 ± 10 years, p =.0061), and had more frequent non‐paroxysmal AF (75% vs. 43%, p =.0018), larger left atrial diameter (43.5 ± 4.5 vs. 39.3 ± 5.7 mm, p =.0003), and higher E/e' ratio (14.4 ± 6.5 vs. 10.5 ± 3.7, p <.0001) compared with P‐LAA < 84 ms patients. After a mean follow‐up period of 665 ± 153 days, Kaplan–Meier curve analysis showed that AF/AT recurrences was more frequently observed in patients with prolonged P‐LAA (Log‐rank p =.0001). Additionally, univariate analysis revealed that P‐LAA prolongation (OR = 1.055 per 1 ms, 95% CI: 1.028–1.087, p <.0001) and the existence of LVA (OR = 5.000, 95% CI: 1.653–14.485 p =.0053) were predictors of AF/AT recurrences after single AF ablation. Conclusions: Our results suggested that prolonged IACT as measured by P‐LAA was associated with LVA and predicts AT/AF recurrence after single AF ablation. [ABSTRACT FROM AUTHOR]

Background: Focal Purkinje ventricular arrhythmias (VAs) might originate from the vicinity of the proximal portion of the cardiac conducting system. This study aimed to clarify the features associated with focal Purkinje VAs originating from the proximal conduction system. Methods: A total of 18 patients with focal Purkinje VAs undergoing radiofrequency catheter ablation (RFCA) were retrospectively examined and divided into the proximal type or the non‐proximal type. The proximal type was defined as having the origin at the proximal half of the interventricular septum, or the proximal half and the septal side of the anterior wall. The 12‐lead electrocardiogram and electrophysiological findings were investigated. Results: Seven patients met criteria for proximal type of focal Purkinje VA. Out of the 7, 4 patients with proximal VAs had multiple QRS morphologies of VAs clinically, whereas out of 11 patients with non‐proximal VAs, only 1 had multiple morphologies (p =.047). VA QRS duration was shorter in the proximal type than in the non‐proximal type (111.2 ± 19.8 ms vs. 135.7 ± 17.7 ms; p =.003). The absolute axis difference between sinus rhythm and VA was smaller in the proximal type (80.4 ± 46.1°vs. 138.8 ± 59.6°; p =.014). The absolute axis difference ≤134° was useful in distinguishing the two types. Recurrence of VA was recorded in 3 proximal type patients and 3 non‐proximal type patients. No procedure‐related conduction block was observed. Conclusion: A VA of absolute axis difference ≤134°, and multiple QRS morphologies of clinical VAs indicate a proximal origin. Focal Purkinje VAs from proximal origins can be suppressed by RFCA without severe conduction disturbance. [ABSTRACT FROM AUTHOR]

Background: When performing an electrical isolation of ipsilateral pulmonary veins (PVs) for atrial fibrillation, physicians often need additional radiofrequency (RF) ablation in the carina region between the superior and inferior PVs to achieve a right PV isolation because of intercaval bundles between the right PVs and right atrium (RA). We compared the efficacy of a high‐power and short‐duration ablation guided by unipolar signal modification (UM) with the conventional method (CM) for ablating epicardial connections between the right PV carina and RA. Methods: The study subjects consisted of patients who underwent an initial box isolation of atrial fibrillation from January 2015 to December 2019 at Nara Medical University Hospital. Among these patients, 94 and 65 patients who met the criteria were assigned to the CM and UM groups, respectively. We retrospectively analyzed the anterior ablation line of the right PV using an electroanatomical mapping system. Patients whose initial ablation line included the right PV carina were excluded. Results: Six and seven patients were, respectively, excluded from the CM and UM groups. Among 88 CM group patients, 21 needed additional right PV carina ablation, while among 58 UM group patients, 30 needed additional right PV carina ablation (p =.001). No anatomical factors were associated with the additional right PV carina ablation. Conclusions: Compared to the CM group, a box isolation was less achievable without RF ablation at the right PV carina in the UM group. We should consider a long‐duration ablation for epicardial connections between the right PV carina and RA. [ABSTRACT FROM AUTHOR]

Background: The outcome of carpal tunnel release (CTR) one year postoperatively was assessed by the Japanese version of Carpal tunnel syndrome questionnaire, CTSI-JSSH. Patients were further graded by the electrophysiological severity scale and the CTSI-JSSH scores were compared amongst the Stages before surgery and one-year postoperatively.Methods: This study included 247 hands and the mean age of the patients was 68 years (range:26-91). They completed the CTSI-JSSH consisting of the two subscales of the symptom scale (CTSI-JSSH-SS) and the functional scale (CTSI-JSSH-FS) both preoperatively and at the follow-up period of one year. The change of the scores of the CTSI-JSSH-SS, CTSI-JSSH-FS and total CTSI-JSSH were examined. Electrophysiological examination was performed before CTR and graded according to the electrophysiological severity scale as Stage 1-5. The scores of the CTSI-JSSH-SS, CTSI-JSSH-FS and total CTSI-JSSH were compared amongst Stage 1-5.Results: All CTSI-JSSH-SS, CTSI-JSSH-FS and total CTSI-JSSH scores improved significantly one-year postoperatively. Also, the standardized response mean (SRM) and effect size (ES) showed large responsiveness, i.e. 1.36/1.43, 1.12/1.08 and 1.43/1.45 respectively. There was no significant difference in the score of the CTSI-JSSH-SS, CTSI-JSSH-FS and total CTSI-JSSH amongst any of the Stages preoperatively, while the scores in Stage 5 were significantly inferior to the ones in Stages 3 and 4 one-year postoperatively.Conclusions: The clinical outcomes of CTR were favorable by assessment of the CTSI-JSSH. We suggest the postoperative inferior scores in Stage 5 may be due to the potential axonal damage which could explain the disappearance of distal motor latency and sensory nerve conduction velocity in Stage 5. [ABSTRACT FROM AUTHOR]

Oxytocin (Oxt) is known to regulate social communication, stress and body weight. The activation of Oxt receptors (OTR) has clinical potential to abate stress disorders and metabolic syndrome. Kamikihito (KKT) is a traditional Japanese medicine used to treat psychological stress-related disorders. We investigated the effects of KKT, its ingredients and chemical components on Oxt neurons and OTR. C-Fos expression was examined after oral and peripheral administration of KKT in rats. Electrophysiological change of Oxt neurons and Oxt release upon application of KKT were measured in rat brain slice. The direct effect of KKT, its ingredients and its chemical components were examined by cytosolic Ca2+ ([Ca2+]i) measurement in Oxt neurons and OTR-expressing HEK293 cells. Both intraperitoneal and oral administration of KKT in rats induced c-Fos expression in neurons of the paraventricular nucleus (PVN) including Oxt neurons. Application of KKT induced activation of Oxt neurons and Oxt release. KKT increased [Ca2+]i in OTR-expressing HEK293 cells, and failed to activate with OTR antagonist. KKT-induced PVN Oxt neuron activation was also attenuated by OTR antagonist. Seven chemical components (rutin, ursolic acid, (Z )-butylidenephtalide, p-cymene, senkunolide, [6]-shogaol, [8]-shogaol) of three ingredients (Zizyphi Fructus, Angelicae Acutilobae Radix, Zingiberis Rhizoma) from KKT had potential to activate OTR. KKT can directly activate PVN Oxt neurons by interacting with OTR. The interaction of seven chemical components from KKT may contribute to activate OTR. Effect of KKT on Oxt neurons and OTR may contribute to the treatment of Oxt related disorders. [ABSTRACT FROM AUTHOR]

This study explores the use of sediment microbial fuel cells (SMFCs) to generate a safe, stable, and efficient supply of bioelectricity to sensors and simultaneously improve sediment quality. Supplying energy to geoenvironmental monitoring sensors remains a challenge as traditional batteries and solar cells are limited by the need to recharge and the erratic weather condition, respectively. Four different sediments from the Yamaguchi bay located in south part of the Honshu island, Japan were experimented on. The acid volatile sulfide (AVS) was the main source of contamination in the intertidal zone and was, hence, used as an indicator for possible bioremediation. Various factors have been studied for its effect on voltage generation. Voltage generation was dependent on the microbes in and grain size distribution of the sediment. It was found that voltage values showed almost twice when two anodes were used instead of a single anode. As the temperature reached optimum temperature of the enzymes of the Geobacteria , the increased activity lead to higher voltage. SMFC was effective in reducing the AVS value of the sediment. SMFCs in the field exhibited greater voltage generation compared to SMFCs of the same size in the laboratory. A positive correlation between voltage generation and AVS reduction was demonstrated. • Both laboratory and field tests conducted and compared result of an intertidal zone. • Field test showed more power density than laboratory test. • Some factors affecting the bioelectricty generation have revealed from intertidal zone. • Sediment microbial fuel cell can increase the rate of remediation in the sulphide contaminated soil. [ABSTRACT FROM AUTHOR]

Background: Telethonin (TCAP) is a Z‐disk protein that maintains cytoskeletal integrity and various signaling pathways in cardiomyocytes. TCAP is shown to modulate α‐subunit of the human cardiac sodium channel (hNav1.5) by direct interactions. Several TCAP variants are found in cardiomyopathies. We sought to investigate whether TCAP variants are associated with arrhythmia syndromes. Methods: Mutational analyses for TCAP were performed in 303 Japanese patients with Brugada syndrome, arrhythmogenic right ventricular cardiomyopathy, and J‐wave pattern ECG. Using patch‐clamp techniques, electrophysiological characteristics of hNav1.5 were studied in HEK‐293 cells stably expressing hNav1.5 and transiently transfected with wild‐type (WT) or variant TCAP. Results: We identified two TCAP variants, c.145G>A:p.E49K and c.458G>A:p.R153H, in four individuals. p.E49K was found in two patients with ARVC or BrS. p.R153H was found in two patients with BrS or J‐wave pattern ECG. No patient had variant hNav1.5. Patch‐clamp experiments demonstrated that peak sodium currents were significantly reduced in cells expressing p.R153H and p.E49K compared with WT‐TCAP (66%, p.R153H; 72%, p.E49K). Voltage dependency of peak IV curve was rightward‐shifted by 5 mV in cells expressing p.E49K compared with WT‐TCAP. Voltage dependency of activation was not leftward‐shifted by p.R153H, while voltage dependency of steady‐state inactivation was leftward‐shifted by p.E49K. Conclusions: We found two TCAP variants in the patients with BrS, J‐wave pattern ECG, and ARVC that can cause loss‐of‐function of the hNav1.5 in heterologous expression systems. Our observation suggests that these variants might impair INa and be associated with the patients' electrophysiological phenotypes. Further studies linking our experimental data to clinical phenotypes are warranted. [ABSTRACT FROM AUTHOR]

Heterozygous mutations in the Berardinelli‐Seip congenital lipodystrophy 2 (BSCL2) gene have been reported with different clinical phenotypes including Silver syndrome (SS)/spastic paraplegia 17 (SPG17), distal hereditary motor neuropathy type V (dHMN‐V), and Charcot‐Marie‐Tooth (CMT) disease type 2. We screened 407 Japanese patients who were clinically suspected of having CMT by exome sequencing and searched mutations in BSCL2. As a result, we identified five patients with heterozygous mutations in BSCL2. We confirmed three cases of known mutations (p.N88S and p.S90L) and two cases of novel mutations (p.N88T and p.S141A). The clinical features of the cases with known mutations in Japan were similar to those previously reported in other countries. In particular, there were many cases with sensory disturbance. The case with p.N88T mutation showed severe phenotype such as early onset age and prominent vocal cord paresis. The case with p.S141A mutation showed characteristics of demyelinating neuropathy such as CMT disease type 1 by electrophysiological examination. In this article, we report the clinical features and spread of cases with BSCL2 mutation in a Japanese cohort. [ABSTRACT FROM AUTHOR]

Prior theory and evidence suggest that native East Asians tend to down-regulate their emotional arousal to negatively valenced experiences through expressive suppression, an emotion regulation technique focused on suppressing one's emotional experience. One proposed explanation for this choice of regulation strategy and its efficacy is rooted in their commitment to the cultural value of interdependence with others. However, prior work has not yet thoroughly supported this hypothesis using in vivo neural correlates of emotion regulation. Here, we utilized an established electroencephalogram (EEG) correlate of emotional arousal, the late positive potential (LPP), to examine whether down-regulation of the LPP in native East Asians might be particularly pronounced for those relatively high in interdependent self-construal. In this study, native Japanese participants attempted to suppress their emotional reaction to unpleasant images during EEG recording. In support of the hypothesis that emotion suppression among native East Asians is influenced by the cultural value of interdependence, there was a significant effect of interdependent self-construal on the LPP. Specifically, those relatively high in interdependent (versus independent) self-construal exhibited a smaller LPP in response to unpleasant pictures when instructed to suppress their emotions versus a passive viewing condition. However, this effect was negligible for those relatively low in interdependent self-construal, suggesting that cultural values impact the in vivo efficacy of different emotion regulation techniques. These results demonstrate the importance of identifying correspondence between self-report measures and in vivo correlates of emotion regulation in cross-cultural research. • Measured the late positive potential (LPP) while viewing neutral or unpleasant images. • Native East Asians were instructed to use expressive suppression or passive viewing. • Interdependent self-construal predicted downregulation of the LPP during suppression. • Emotion regulation via expressive suppression may be dependent on cultural attitudes. • This extends previous findings to native East Asians living in an East Asian culture. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to develop a quantitative evaluation method of interference patterns on needle electromyography that is easy to apply in clinical use and to examine its usefulness. Diagnostic electrophysiological assessments are important for physiatrists, and correct diagnosis and assessment are essential for proper rehabilitation. Design: A total of 112 maximum interference patterns of upper extremity muscles suspected of being affected by neuropathy were quantitatively evaluated based on the parameters of integration values, mean amplitudes, the number of peaks, and activity. "Activity" was defined as the sum of the time during which myoelectric signals were recorded during 1 sec with maximum voluntary contraction, and it was expressed as a percentage. The relationships of the previous parameters with spontaneous pathological potentials and polyphasic motor unit potentials were examined. Results: The area under the curve of the receiver operating characteristic curve for the diagnosis of neuropathy was the highest using activity (0.917). The integral value and mean amplitude were useful for the diagnosis of cases with chronic neuropathy showing slightly decreased interference patterns. Conclusions: The quantitative evaluation of the maximal contraction interference pattern in this study was useful for the diagnosis of neuropathy. [ABSTRACT FROM AUTHOR]

Objective: To investigate the cost differences between magnetic resonance-guided focussed ultrasound (MRgFUS) and unilateral deep brain stimulation (DBS) for the treatment of medication-refractory essential tremor (ET) in Japan using a cost-minimisation model. Methods: A cost-minimisation model estimated total costs for MRgFUS and unilateral DBS by summing the pre-procedure, procedure, and post-procedure costs over a 12-month time horizon, using data from published sources and expert clinical opinion. The model base case considered medical costs from fee-for-service tariffs. Scenario analyses investigated the use of Diagnosis Procedure Combination tariffs, a diagnosis-related group-based fixed-payment system, and the addition of healthcare professional labour costs healthcare professionals using tariffs from the Japanese Health Insurance Federation for Surgery. One-way sensitivity analyses altered costs associated with tremor recurrence after MRgFUS, the extraction rate following unilateral DBS, the length of hospitalisation for unilateral DBS and the procedure duration for MRgFUS. The impact of uncertainty in model parameters on the model results was further explored using probabilistic sensitivity analysis. Results: Compared to unilateral DBS, MRgFUS was cost saving in the base case and Diagnosis Procedure Combination cost scenario, with total savings of JPY400,380 and JPY414,691, respectively. The majority of savings were accrued at the procedural stage. Including labour costs further increased the cost differences between MRgFUS and unilateral DBS. Cost savings were maintained in each sensitivity analysis and the probabilistic sensitivity analysis, demonstrating that the model results are highly robust. Conclusions: In the Japanese healthcare setting, MRgFUS could be a cost saving option versus unilateral DBS for treating medication-refractory ET. The model results may even be conservative, as the cost of multiple follow-ups for unilateral DBS and treatment costs for adverse events associated with each procedure were not included. This model is also consistent with the results of other economic analyses of MRgFUS versus DBS in various settings worldwide. [ABSTRACT FROM AUTHOR]

Chronic arsenic intoxication is known to cause multisystem impairment and is still a major threat to public health in many countries. In Toroku, a small village in Japan, arsenic mines operated from 1920 to 1962, and residents suffered serious sequelae of arsenic intoxication. We have performed annual medical examinations of these residents since 1974, allowing us to characterize participants’ long-term health following their last exposure to arsenic. The participants could not be described as having “chronic arsenic intoxication,” because their blood arsenic levels were not measured. In this study, we defined them as having “probable arsenic intoxication.” Symptoms frequently involved the sensory nervous system, skin, and upper respiratory system (89.1-97.8%). In an analysis of neurological findings, sensory neuropathy was common, and more than half of the participants complained of hearing impairment. Longitudinal assessment with neurological examinations and nerve conduction studies revealed that sensory dysfunction gradually worsened, even after exposure cessation. However, we could not conclude that arsenic caused the long-term decline of sensory function due to a lack of comparisons with age-matched healthy controls. This is the first study to characterize the longitudinal sequelae after probable arsenic exposure. Our study will be helpful to assess the prognosis of patients worldwide who still suffer from chronic arsenic intoxication. [ABSTRACT FROM AUTHOR]

Abstract: Mutations in small heat shock protein beta‐1 (HspB1) have been linked to Charcot‐Marie‐Tooth (CMT) disease type 2F and distal hereditary motor neuropathy type 2B. Only four cases with HSPB1 mutations have been reported to date in Japan. In this study between April 2007 and October 2014, we conducted gene panel sequencing in a case series of 1,030 patients with inherited peripheral neuropathies (IPNs) using DNA microarray, targeted resequencing, and whole‐exome sequencing. We identified HSPB1 variants in 1.3% (13 of 1,030) of the patients with IPNs, who exhibited a male predominance. Based on neurological and electrophysiological findings, seven patients were diagnosed with CMT disease type 2F, whereas the remaining six patients were diagnosed with distal hereditary motor neuropathy type 2B. P39L, R127W, S135C, R140G, K141Q, T151I, and P182A mutations identified in 12 patients were described previously, whereas a novel K123* variant with unknown significance was found in 1 patient. Diabetes and impaired glucose tolerance were detected in 6 of the 13 patients. Our findings suggest that HSPB1 mutations result in two phenotypes of inherited neuropathies and extend the phenotypic spectrum of HSPB1‐related disorders. [ABSTRACT FROM AUTHOR]

Charcot-Marie-Tooth disease (CMT) constitutes a heterogeneous group affecting motor and sensory neurons in the peripheral nervous system. MFN2 mutations are the most common cause of axonal CMT. We describe the clinical and mutational spectra of CMT patients harboring MFN2 mutations in Japan. We analyzed 1,334 unrelated patients with clinically suspected CMT referred by neurological and neuropediatric departments throughout Japan. We conducted mutation screening using a DNA microarray, targeted resequencing, and whole-exome sequencing. We identified pathogenic or likely pathogenic MFN2 variants from 79 CMT patients, comprising 44 heterozygous and 1 compound heterozygous variants. A total of 15 novel variants were detected. An autosomal dominant family history was determined in 43 cases, and the remaining 36 cases were reported as sporadic with no family history. The mean onset age of CMT in these patients was 12 ± 14 (range 0-59) years. We observed neuropathic symptoms in all patients. Some had optic atrophy, vocal cord paralysis, or spasticity. We detected a compound heterozygous MFN2 mutation in a patient with a severe phenotype and the co-occurrence of MFN2 and PMP22 mutations in a patient with an uncommon phenotype. MFN2 is the most frequent causative gene of CMT2 in Japan. We present 15 novel variants and broad clinical and mutational spectra of Japanese MFN2-related CMT patients. Regardless of the onset age and inheritance pattern, MFN2 gene analysis should be performed. Combinations of causative genes should be considered to explain the phenotypic diversity. [ABSTRACT FROM AUTHOR]

Background Although a ventriculoatrial interval (VAI) of ≤70 ms is used to distinguish atrioventricular nodal reentrant tachycardia from orthodromic atrioventricular reciprocating tachycardia (AVRT), a VAI of ≤70 ms is sometimes observed in cases of AVRT. The study aimed to evaluate the short VAI that is seen in AVRT and to understand its underlying mechanism. Methods Electrophysiologic studies of 46 consecutive patients with AVRT involving an accessory pathway (AP) were examined retrospectively. Results AP was right sided in seven patients and left sided in 39. A VAI (interval from QRS onset to the earliest intracardiac atrial electrogram recorded by any mapping catheter during AVRT) ≤70 ms during AVRT (short VAI) was observed in eight patients: six with a left lateral AP and two with a left posteroseptal AP. During AVRT involving a left-sided AP, the QRS-V interval (from the earliest QRS onset to the local ventricular electrogram at a site which showed earliest atrial electrogram recorded from the coronary sinus catheter) was significantly shorter (37 ± 7 ms vs 54 ± 13 ms, P = 0.001) and supernormal conduction (QRS duration or the QRS-V interval shortening by ≥10 ms during AVRT) was more frequently seen (63% vs 6%, P = 0.02) in the short VAI group than in the normal VAI group. Furthermore, these parameters were shown to be determinants for short VAI. Conclusions A short VAI is sometimes observed during AVRT involving a left-sided AP. The short VAI may be caused by rapid propagation or supernormal conduction between the proximal Purkinje-muscle junction and basal left ventricular myocardium. [ABSTRACT FROM AUTHOR]

Purpose Our recent report demonstrated that atrial electromechanical conduction time ( EMT-ε) measured with speckle tracking echocardiography could predict cardiac events in patients with pathological left ventricular hypertrophy. This study aimed to validate EMT-ε by comparison with electroanatomical mapping and to investigate the clinical utility of EMT-ε in patients with atrial fibrillation ( AF) undergoing catheter ablation. Methods Forty-six patients with preserved LV ejection fraction ( LVEF ≥ 50%) undergoing pulmonary vein isolation ( PVI) for AF were studied. Atrial electrical conduction delay was determined by measuring atrial electrical activation time ( EAT) using three-dimensional electroanatomical mapping just after PVI. Echocardiographic parameters were acquired within 24 hours and at 6 months after PVI. The study also included 10 control subjects. Results AF patients had a larger left atrial ( LA) volume index ( LAVI) and more prolonged EMT-ε compared with control subjects. According to the validation study, EAT was closely related to EMT-ε and a′, and this association was independent of LAVI and the presence of persistent AF ( EMT-ε: R2 = 0.342, P < 0.0001, a′: R2 = 0.337, P < 0.0001). At 6 months after PVI, LAVI and EMT-ε were significantly improved. During continued follow-up beyond 6 months (total follow-up, 26 ± 12 months), the EMT-ε shortening at 6 months after PVI was significantly greater in AF-free patients than patients with AF recurrence. Conclusions: This study suggested that the EMT-ε could be a useful echocardiographic marker of LA electromechanical abnormalities in patients with AF. [ABSTRACT FROM AUTHOR]

AV Nodal Remodeling Induced by AF Background An animal experiment showed that long-term atrial pacing or persistent atrial fibrillation (AF) caused electrical remodeling of the atrioventricular (AV) node. We aimed to test the hypothesis that persistent AF decreases the AV conductivity in human hearts. Methods and Results We retrospectively compared the cardiac electrophysiological properties between patients with paroxysmal AF who underwent catheter ablation (PXAF, N = 254) and those with persistent or longstanding persistent AF (PSAF, N = 213). The PSAF patients were more likely than PXAF patients to have longer atrial-His (AH) (96.3 ± 25.7 vs. 91.3 ± 20.4 milliseconds; P = 0.02) and His-ventricle (HV) (43.1 ± 9.4 vs. 41.2 ± 8.6 milliseconds; P = 0.02) intervals. The AV nodal effective refractory period (ERP) (299.1 ± 74.6 vs. 276.2 ± 58.9 milliseconds; P < 0.001) and Wenckebach cycle length (420.9 ± 80.3 vs. 386 ± 58.6 milliseconds; P < 0.001) were also more prolonged in the PSAF patients. We found a dual AV nodal physiology with a similar frequency in both groups. The AH interval, fast pathway ERP, and Wenckebach cycle length in the PSAF patients were more likely than in the PXAF patients to be prolonged among the patients without dual pathways, while those intergroup differences were never seen among the patients with dual pathways. In subgroup analyses including only PSAF patients, there was no difference in the AV conductivity between the patients with persistent AF and those with longstanding persistent AF. Conclusions Persistent AF may cause a mild decrease in the AV nodal function in human hearts. Electrical remodeling may be uncommon if dual AV nodal pathways are present, and its extent may not depend on the duration of persistent AF. [ABSTRACT FROM AUTHOR]

Background Sleep-disordered breathing (SDB) is highly associated with arterial hypertension (HT). Sympathetic hypertonia increases the risk of sudden cardiac death in patients with sleep apnea. This study aims to noninvasively investigate the electrophysiological features in SDB patients with and without arterial HT. Methods Fifty-three patients with SDB were classified into two groups: SDB group and SDB + HT group. Twenty subjects with arterial HT were enrolled as controls (HT group). To assess arrhythmogenic vulnerability, high-resolution 24-hour ambulatory electrocardiograms were obtained for analyzing continuous late potential (LP), T-wave amplitude variability (TAV), and heart rate variability (HRV). Results A higher incidence of positive LP was observed in the SDB + HT (85%) group than that observed in the SDB (50%) and HT (20%) groups (P < 0.01). TAV was highest in the SDB + HT group (78 μV) compared with the SDB (61 μV) and HT groups (42 μV; P < 0.01). Positive LP and TAV values were observed at night in the SDB + HT and SDB groups. The low-frequency/high-frequency of the HRV analysis was highest in the SDB + HT (4.7) group compared with that in the SDB (2.9) and HT (2.9) groups (P = 0.01). Conclusion Nocturnal LP, TAV, and HRV examinations were useful to investigate arrhythmogenesis. SDB patients with arterial HT showed a high prevalence of depolarization and repolarization abnormalities and relative sympathetic hyperactivity. This suggests that an electrophysiological instability is more prevalent in SDB patients with arterial HT. [ABSTRACT FROM AUTHOR]

Background This study aimed to clarify whether retrograde P-wave amplitude during tachycardia can be used to differentiate slow-slow form of atrioventricular nodal reentrant tachycardia (S/S-AVNRT) from atrioventricular reentrant tachycardia through a posteroseptal accessory pathway (PS-AVRT). Methods Sixteen patients with S/S-AVNRT and 14 patients with PS-AVRT constituted the study group. Electrocardiographic and electrophysiological parameters were compared between both the groups. HA(CS-His), which indicates the location of the earliest atrial activation site during tachycardia, was calculated as the difference of the shortest HA interval in the His bundle region and the coronary sinus region. Results Negative deflection of the retrograde P wave during tachycardia was significantly greater in S/S-AVNRT than in PS-AVRT in the inferior leads (lead aVF, −0.22 ± 0.04 mV vs −0.10 ± 0.07 mV; P < 0.001). Among the electrocardiographic parameters, retrograde P-wave amplitude in lead aVF had the highest diagnostic accuracy (area under the curve 0.975, sensitivity 93%, and specificity 88% for a cutoff value of −0.16 mV). HA(CS-His) was negatively greater in S/S-AVNRT than in PS-AVRT (−24 ± 13 ms vs −3 ± 18 ms; P = 0.001), and was significantly correlated with the retrograde P-wave amplitude in lead aVF (P = 0.004). Conclusion Deeper negative deflection of the retrograde P wave in the inferior lead can help differentiate S/S-AVNRT from PS-AVRT. [ABSTRACT FROM AUTHOR]

LA Wall Thickness, LA Electrogram, and Dormant PV Conduction Introduction Atrial remodeling plays a key role in development of the substrate for atrial fibrillation (AF). Whether the wall thicknesses of the left atrium (LA) and pulmonary vein (PV)-LA junction affect remodeling and AF ablation is unknown. We investigated the relationship between wall thicknesses, electrogram characteristics, and adenosine triphosphate (ATP)-provoked dormant PV conduction as they pertain to AF. Methods In 50 patients with AF and 25 patients without AF, wall thicknesses of the LA and PV-LA junction were measured on 320-slice computed tomography images. For the AF patients, NavX-based voltage maps generated during sinus rhythm were obtained, and ATP-provoked dormant PV conduction after PV isolation was evaluated. Results Walls of the LA and PV-LA junction were significantly thicker in the AF patients than in the control patients (1.83 ± 0.29 mm vs. 1.59 ± 0.28 mm, respectively; P = 0.0010; and 0.88 ± 0.14 mm vs. 0.65 ± 0.11 mm, P<0.0001, respectively). Wall thickness at the PV-LA junction was independently associated with AF (β = 0.40, P = 0.0002). In AF patients, the walls of the PV-LA junction showed stepwise thickening across bipolar voltages indicative of severe (bipolar voltage <33rd percentile) to moderate (33rd-66th percentiles) to mild fibrosis/scarring (≥66th percentile). Walls of the PV-LA junction with dormant PV conduction were significantly thicker than those without it (0.94 ± 0.19 mm vs. 0.86 ± 0.21 mm, respectively; P = 0.0025). Conclusions Together, the association between thickened PV-LA junction walls and AF and the increased bipolar voltage suggests that such wall thickening increases PV electrical activities, leading to initiation and maintenance of AF and perhaps to ATP-provoked dormant PV conduction. [ABSTRACT FROM AUTHOR]

Background Substrate-based catheter ablation (CA) can be applied to more complicated cases such as hemodynamically unstable ventricular tachycardia (VT). We aimed to compare the efficacy between substrate-based and activation/entrainment-based ablation. Methods We investigated 85 consecutive patients (62 male, 53 ± 16 years) who underwent CA of VT to analyze the relationship between the ablation strategy and clinical outcome. The patients included 34 individuals with arrhythmogenic right ventricular cardiomyopathy, 16 with ischemic heart disease, 14 with dilated cardiomyopathy, 11 with sarcoidosis, and 10 with other heart diseases. The primary strategy was activation/entrainment mapping (Group-AE, N = 35); otherwise, substrate-based strategy was adopted (Group-S, N = 50) because of non-inducibility of VT or hemodynamic instability. Successful CA was defined as the non-inducibility of any VT at the end of the procedure in those with inducible clinical VT before ablation, and substrate elimination in those without. Results There were no significant differences in the left ventricular function, percentage of implantable cardioverter-defibrillator implantations, results of CA, and number of radiofrequency applications between Group-S and Group-AE. During 5 years of follow-up, there were no significant differences in sustained VT recurrences (15/50 vs. 15/35, P = 0.22), and cardiac death (2/50 vs. 3/35, P = 0.38). In patients with inducible VT before ablation, the elimination of the VT inducibility was associated with a lower recurrence rate (12/47 vs. 16/26, P = 0.003). Conclusions The substrate-based strategy adopted as an alternative option when the activation/entrainment-based strategy was unable to be performed resulted in a comparable VT recurrence rate. The extinction of VT inducibility achieved a favorable prognosis in structural heart disease patients. [ABSTRACT FROM AUTHOR]

Incomplete Cure of TIC with Rate Control Background It is uncertain whether rate or rhythm control is more favorable for patients experiencing tachycardia-induced cardiomyopathy (TIC) secondary to rapid atrial fibrillation (AF). Methods and Results We compared the electrophysiological and hemodynamic properties and outcome after AF ablation in 20 patients with a history of decompensated TIC who maintained sinus rhythm or had paroxysmal AF (group 1), 32 with a history of decompensated TIC who had persistent or longstanding persistent AF (group 2), 377 without TIC who had paroxysmal AF (group 3), and 225 without TIC who had persistent or longstanding persistent AF (group 4). The corrected sinus node recovery time was more prolonged in group 2 than in groups 1, 3, or 4 (1,066 ± 946 vs. 416 ± 188, 450 ± 322 and 590 ± 329 milliseconds; P < 0.001, respectively). The mean left atrial pressure in group 2 was greater than that in groups 1, 3, or 4 (13.9 ± 6.5 vs. 7.5 ± 3.1, 8.2 ± 4.1 and 10.8 ± 4.2 mmHg; P < 0.001, respectively). The left ventricular ejection fraction assessed after the recovery from the decompensation was more decreased in group 2 than in group 1; however, it almost returned to normal if sinus rhythm was maintained after the AF ablation in group 2. The presence of a history of TIC did not predict an AF recurrence after the ablation. Conclusions Heart rate control during AF without sinus conversion may result in an incomplete cure of TIC, suggesting the advantages of rhythm control with ablation in patients with TIC. [ABSTRACT FROM AUTHOR]

Optimal Contact Force for AF Ablation Background Regional differences in optimal contact force (CF) to prevent acute pulmonary vein reconnection (APVR) during catheter ablation for atrial fibrillation (AF) remain unclear. Objective The purpose of this study was to evaluate regional difference in optimal CF during AF ablation. Methods This single-center observational study evaluated data from 57 consecutive drug-refractory AF patients (mean age, 62 ± 11 years; 43 males) who underwent initial pulmonary vein isolation (PVI) using the THERMOCOOL® SMARTTOUCH™ (Biosense Webster, Diamond Bar, CA, USA) catheter from June to August 2013. APVR was defined as the time-dependent reconnection >20 minutes after initial PVI and/or reconnection evoked by intravenous adenosine administration (20 mg). Point-by-point relationships between the reconnected points and their CF values were evaluated. Results Total 72 gaps causing APVR were observed. Of a total of 4,421 ablation points, 285 (6.4%) were associated with APVR. The average CF value of the points with APVR was significantly lower than that of those without (APVR vs. no APVR; 7.5 ± 6.7 g vs. 9.9 ± 8.4 g; P < 0.0001). The areas under the curve and optimal CF values differed between segments (range 0.593-0.761 and 10-22 g, respectively). The optimal CF value was highest in bottom of the right PV and posterosuperior right PV segments (22 g) and lowest in posteroinferior right PV segment (10 g). Conclusions There was a regional difference in optimal CF values to prevent APVR, and the optimal CF value to prevent APVR with >95% probability was 10-22 g, depending on the individual peri-PV segments. [ABSTRACT FROM AUTHOR]

Novel KCNH2 Mutations in Brugada Syndrome Background Brugada syndrome (BrS) is an inherited disease characterized by right precordial ST segment elevation on electrocardiograms (ECGs) that predisposes patients to sudden cardiac death as a result of polymorphic ventricular tachyarrhythmia or ventricular fibrillation (VF). In BrS patients, except for SCN5A, mutations in other responsible genes are poorly elucidated. Methods and Results We identified 4 KCNH2 mutations, T152I, R164C, W927G, and R1135H, in 236 consecutive probands with BrS or Brugada-like ECG. Three of these mutation carriers showed QTc intervals shorter than 360 milliseconds and 1 experienced VF. We performed patch-clamp analyses on IKr reconstituted with the KCNH2 mutations in Chinese hamster ovary cells and compared the phenotypes of the patients with different genotypes. Three mutations, R164C, W927G, and R1135H, increased IKr densities. Three mutations, T152I, R164C, and W927G, caused a negative shift in voltage-dependent activation curves. Only the R1135H mutant channel prolonged the deactivation time constants. We also identified 20 SCN5A and 5 CACNA1C mutation carriers in our cohort. Comparison of probands' phenotypes with 3 different genotypes revealed that KCNH2 mutation carriers showed shorter QTc intervals and SCN5A mutation carriers had longer QRS durations. Conclusions All KCNH2 mutations that we identified in probands with BrS exerted gain-of-function effects on IKr channels, which may partially explain the ECG findings in our patients. [ABSTRACT FROM AUTHOR]

Arrhythmogenic SVC and AF Background It is well known that superior vena cava (SVC) is one of the important non-pulmonary vein (PV) foci of atrial fibrillation (AF). However, little is known regarding the role of arrhythmogenic SVC in AF. Methods and Results Among 1,425 patients who underwent AF ablation in 2 centers, PV antrum isolation was performed in all and SVC isolation was added in 74 (5.2%) patients with arrhythmogenic SVC (58 ± 10 years; 54 males) when the latter was identified as an AF source. The arrhythmogenicity was identified at the 1st, 2nd, and 3rd procedures in 62 (83.8%), 7 (9.5%), and 5 (6.7%) patients, respectively. In 7 (9.5%), 26 (35.1%), and 14 (18.9%) patients, it was identified following adenosine injection, isoproterenol infusion, and electrical cardioversion, respectively. SVC triggering AF was identified in 58 out of 74 (78.4%) patients. In this subset, AF initiated from SVC; however, AF cycle length was longer in SVC than in the right atrium once AF persisted, which suggested its role as an initiator. In 24 (32.4%) patients following the isolation of SVC, AF terminated or converted to atrial flutter and/or confined SVC tachycardia/fibrillation was observed, which suggested its role as a perpetuator. Sixty-four (86.5%) of 74 patients were free from any atrial tachyarrhythmias without antiarrhythmic drugs mean 12.1 ± 9.4 months after the last ablation procedure (mean 1.38 procedures/patient). Conclusions In a subset of patients, SVC plays a role in AF not only as an initiator/trigger but also as a driver/perpetuator. [ABSTRACT FROM AUTHOR]

Background Mechanical alternans (MA) and electrical alternans (EA) are predictors of cardiac events. Experimental studies have suggested that refractoriness of calcium cycling underlies these cardiac alternans. However, refractoriness of left ventricular contraction has not been examined in patients with cardiac alternans. Methods In 51 patients with miscellaneous heart diseases, incremental right atrial pacing was performed to induce MA and EA. MA was quantified by alternans amplitude (AA: the difference between left ventricular dP/dt of a strong beat and that of a weak beat), and AA at 100/min (AA100) and maximal AA (AAmax) were measured. EA was defined as alternation of T wave morphology in 12-lead electrocardiogram. Relative refractoriness of left ventricular contraction was examined by drawing the mechanical restitution curve under a basal coupling interval (BCL) of 600 ms (100/min) and was assessed by the slope at BCL (Δmechanical restitution). Postextrasystolic potentiation (PESP) was also examined and the slope of PESP curve (ΔPESP) was assessed as a property to alternate strong and weak beats. Results MA and EA were induced in 19 patients and in none at 100/min or less, and at any heart rate in 32 and in 10, respectively. AA100 and AAmax correlated positively with Δmechanical restitution and negatively with ΔPESP. Patients with EA had a significantly larger Δmechanical restitution and a significantly larger absolute value of ΔPESP than those without. Conclusions In patients with MA and EA, the left ventricular contractile force during tachycardia is under relative refractoriness and prone to cause large fluctuation of contractile force. [ABSTRACT FROM AUTHOR]

Channelopathies in Infantile Arrhythmias Background Fatal ventricular arrhythmias in the early period of life have been associated with cardiac channelopathies for decades, and postmortem analyses in SIDS victims have provided evidence of this association. However, the prevalence and functional properties of cardiac ion channel mutations in infantile fatal arrhythmia cases are not clear. Methods and Results Seven infants with potentially lethal arrhythmias at age < 1 year (5 males, age of onset 44.1 ± 72.1 days) were genetically analyzed for KCNQ1, KCNH2, KCNE1-5, KCNJ2, SCN5A, GJA5, and CALM1 by using denaturing high-performance liquid chromatography and direct sequencing. Whole-cell currents of wildtype and mutant channels were recorded and analyzed in Chinese hamster ovary cells transfected with SCN5A and KCNH2 cDNA. In 5 of 7 patients, we identified 4 mutations (p.N1774D, p.T290fsX53, p.F1486del and p.N406K) in SCN5A, and 1 mutation (p.G628D) in KCNH2. N1774D, F1486del, and N406K in SCN5A displayed tetrodotoxin-sensitive persistent late Na+ currents. By contrast, SCN5A-T290fsX53 was nonfunctional. KCNH2-G628D exhibited loss of channel function. Conclusion Genetic screening of 7 patients was used to demonstrate the high prevalence of cardiac channelopathies. Functional assays revealed both gain and loss of channel function in SCN5A mutations, as well as loss of function associated with the KCNH2 mutation. [ABSTRACT FROM AUTHOR]

Dominant Frequency-Based Ablation of Atrial Fibrillation Introduction Atrial substrates with high-dominant frequency (DF) and complex fractionated atrial electrogram (CFAE) sites have sources maintaining atrial fibrillation (AF) and are potential AF ablation targets. This study aimed to evaluate an approach of circumferential pulmonary vein isolation (PVI) followed by a DF and CFAE site ablation. Methods and Results Fifty consecutive AF patients (23 paroxysmal, 9 persistent, and 18 longstanding persistent) underwent ablation, using NavX. When AF continued after circumferential PVI, high-DF sites of ≥8 Hz and then continuous left atrial (LA) CFAE sites defined by fractionated intervals (FI) of ≤50 milliseconds including the coronary sinus and right atrium were targeted. A total of 45.1% of high-DF and 48.1% of continuous CFAE sites significantly decreased after PVI (P < 0.001). The mean LA DF and FI significantly decreased and prolonged, respectively, after PVI (P < 0.001). Only 14.1% of all high-DF sites after PVI overlapped with continuous CFAE sites. AF terminated at high-DF sites in 11 (22%) patients and continuous CFAE sites in 1 (2%). AF could be induced in only 8% of patients after the procedure. The mean LA DF value before ablation was significantly lower in those without recurrence (P = 0.003). AF freedom on antiarrhythmic drugs was 96% and 59%, respectively, in the paroxysmal and nonparoxysmal AF patients (89% persistent and 44% longstanding persistent) after 1 procedure over a 12-month follow-up. Conclusions A combined high-DF and continuous CFAE site ablation in all chambers after circumferential PVI may be effective in the paroxysmal and persistent AF patients. [ABSTRACT FROM AUTHOR]

A Subgroup of IVF Patients Introduction The presence of early repolarization (ER) recently has been considered as a prognostic marker for sudden cardiac death in patients with idiopathic ventricular fibrillation (IVF), but there are certain numbers of IVF patients lacking ER. We aimed to clarify the clinical and electrocardiographic characteristics of the patients with IVF in the presence and absence of ER. Methods and results We studied 64 consecutive IVF patients from the Japan Idiopathic Ventricular Fibrillation Study (J-IVFS) registry, which subjected with at least one episode of documented VF in the absence of structural heart diseases and excluding Brugada syndrome. We assessed clinical and electrophysiological characteristics in the IVF patients with and without ER. ER was defined as J-point elevation of >0.1 mV in either inferior or lateral leads. Twelve-lead electrocardiogram (ECG) demonstrated 24 (38%) of 64 patients with ER (ER[+] group) and the remaining 40 (62%) patients without ER (ER[-] group ). ER[+] group had a male predominance (92% for males) and ER[-] group revealed nearly equal distribution in both sexes. While no patients in ER[+] group showed intraventricular conduction disturbance (CD) with abnormal axis deviation and/or bundle branch block in ECG, 9 in ER[-] group had signs of CD (ER[-]/CD[+] subgroup). ER[-]/CD[+] subgroup had prolonged P-R interval and QRS duration compared to other patient groups. Conclusion We found 3 distinct ECG patterns in IVF patients. In addition to the presence and absence of ER, there is a subgroup without ER demonstrating intraventricular CD, which represents a distinct clinical entity of IVF. [ABSTRACT FROM AUTHOR]

Background: The effect of atrial fibrillation (AF) ablation on left atrial (LA) function has not been sufficiently determined. Methods: We enrolled 115 consecutive patients with paroxysmal or persistent AF that underwent AF ablation. Multidetector computed tomography was performed in sinus rhythm before and 3 months after ablation to evaluate LA volume (LAV) and function. Estimates of maximum and minimum LAV were used to calculate LA emptying fraction (LAEF) ([maximum- minimum LAV]/maximum LAV × 100). Results: AF ablation significantly decreased maximum LAV (59.0 ± 20.4 to 53.3 ± 16.7 cm3, P = 0.001), and maintained LAEF (44.5 ± 13.1% to 43.7 ± 10.9%, P = 0.49). The larger the baseline maximum LAV, the greater the decrease in LAV after ablation, and a smaller baseline LAEF was associated with a larger recovery of LAEF after ablation (regression coefficient =−0.45 and −0.56, respectively, P < 0.0001). Multivariable analyses revealed that an impaired baseline LAEF was an independent predictor of an improvement in LA function (an increase in LAEF of >10%; odds ratio [OR] = 0.88, P < 0.0001), while an older age and preserved baseline LAEF were independently associated with a deterioration of LA function (a decrease in LAEF of >10%; OR = 1.06, P = 0.03; and OR = 1.10, P = 0.0001). Conclusions: AF ablation appears to have a beneficial effect on LA function in patients with impaired LA function at baseline. However, it may reduce LA function in patients with an older age and preserved baseline LAEF. (PACE 2011;1-8) [ABSTRACT FROM AUTHOR]

BACKGROUND: In Guillain–Barré syndrome (GBS), the diversity in electrophysiological subtypes is unexplained but may be determined by geographical factors and preceding infections. Acute motor axonal neuropathy (AMAN) is a frequent GBS variant in Japan and one study proposed that in Japan, Campylobacter jejuni infections exclusively elicit AMAN. In The Netherlands C jejuni is the predominant type of preceding infection yet AMAN is rare. This may indicate that not all Dutch GBS patients with C jejuni infections have AMAN. OBJECTIVE: To determine if GBS patients with a preceding C jejuni infection in The Netherlands exclusively have AMAN. METHODS: Retrospective analysis of preceding infections in relation to serial electrophysiology and clinical data from 123 GBS patients. C jejuni related cases were defined as having preceding diarrhoea and positive C jejuni serology. Electrophysiological characteristics in C jejuni related cases were compared with those in viral related GBS patients. In addition, eight GBS patients from another cohort with positive stool cultures for C jejuni were analysed. RESULTS: 17 (14%) of 123 patients had C jejuni related GBS. C jejuni patients had lower motor and higher sensory action potentials compared with viral related cases. Nine (53%) C jejuni patients had either AMAN or inexcitable nerves. However, three (18%) patients fulfilled the criteria for acute inflammatory demyelinating polyneuropathy (AIDP). Also, two (25%) of eight additional patients with a C jejuni positive stool sample had AIDP. CONCLUSION: In The Netherlands, C jejuni infections are strongly, but not exclusively, associated with axonal GBS. Some patients with these infections fulfil current criteria for demyelination. [ABSTRACT FROM AUTHOR]

The process of deterioration of peripheral nerve function in familial amyloid polyneuropathy (FAP) with amyloidogenic transthyretin (ATTR) Val30Met has not been systematically evaluated hitherto. We performed nerve conduction studies in 69 patients with FAP with ATTR Val30Met from one of the endemic areas in Japan. Sensory conduction velocity (SCV), motor conduction velocity (MCV), the size of the compound muscle action potential (CMAP) and distal latency (DL) were measured in the ulnar and tibial nerves. SCV was evaluated using the orthodromic method with needle recording electrodes. These electrophysiological parameters were compared with clinical stage of FAP and duration of neuropathy. When subjects noted minimal neuropathic symptoms only in the feet, motor and sensory nerve function in both the hands and feet had already been disturbed. Sensory nerve action potential on the foot disappeared more rapidly than CMAP. CMAP on foot muscle rapidly decreased during the initial 2 years and completely disappeared within 10 years. The duration of illness and deterioration parameters (CMAP of the abductor digiti minimi muscle, MCV and SCV of the ulnar nerve and DL of both ulnar and tibial nerves) were linearly correlated. CMAP was the most sensitive and reliable parameter to evaluate motor nerve degeneration in FAP. [ABSTRACT FROM AUTHOR]

A 76-year-old female developed 2 different ventricular tachycardias (VTs) 5 years after alcohol septal ablation (ASA) for symptomatic hypertrophic obstructive cardiomyopathy. VT#1 was a small macroreentry at the anterior border of the low-voltage zone, suggesting the ASA-scar and eliminated by endocardial ablation at a site recording fractionated potentials covering the mid-diastolic and presystolic periods. VT#2 was a focal VT and eliminated by epicardial cryoablation at the basal posterior left ventricle, suggesting the posterior border of the ASA-scar. Using the electroanatomical mapping, we demonstrated that the mechanism of the VTs was reentry at the edge of the ASA-scar. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1296-1299, November 2010) [ABSTRACT FROM AUTHOR]

The purpose of this study is to evaluate the efficacy of atrial fibrillation (AF) ablation in patients with moderate valvular heart disease (VHD). In total, 534 consecutive patients who underwent AF ablation were enrolled. Patients with a history of valve surgery or other structural heart disease were excluded. Patients with clinically moderate VHD (group-1, n = 45) were compared with those without VHD (control group-2, n = 436). Ipsilateral pulmonary vein antrum isolation (PVAI) was performed with a double Lasso technique in all the patients. Left atrial (LA) linear ablation was undertaken in persistent AF patients, if AF was inducible after PVAI. Patients in group-1 were significantly older and had a larger LA. PVAI was successfully achieved in all the patients. Patients in group-1 received LA linear ablation more frequently during the index procedure. After a median of 26 months from the index procedure, the freedom from AF was significantly lower in group-1 than group-2 off antiarrhythmic drugs (AADs) (47% vs 69%, P = 0.002). Although there were more number of total procedures in group-1 than group-2, the freedom from AF was lower at median 24 months after the last procedure (78% vs 87%, P = 0.038). There was no significant difference in the freedom from AF on AADs (91% vs 95%, P = 0.356) or complication rate between the 2 groups. Atrial tachycardia following the index procedure was observed more frequently in group-1 (P = 0.001). The patients with VHD undergoing AF ablation are less likely to remain in sinus rhythm at long term without AADs than those without VHD. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1193-1198, November 2010) [ABSTRACT FROM AUTHOR]

Background: The purpose of this study is to examine the use of daikenchuto (DKT), a traditional Japanese medicine, as a potential treatment for opiate-induced slowing of intestinal transit in an isolated guinea pig colon model of motility. Methods: Isolated segments of distal guinea pig colon were mounted in a perfusion chamber and imaged with a digital video camera interfaced with a computer. Fecal pellets were inserted into the oral end of the colonic segment and the rates of propulsive motility over a 3 to 4cm segment of colon were determined in the presence and absence of test compounds. In addition, intracellular recordings were obtained from intact circular muscle, and the responsiveness of inhibitory and excitatory junction potentials to DKT was evaluated. Results: The addition of D-Ala2, N-Me-Phe4, Gly-ol5 (DAMGO), a selective μ-receptor agonist, caused a concentration dependent decrease in colon motility. Naloxone did not affect basal activity, but partially restored motility in the DAMGO treated preparations. DKT (1×10−4–3×10−4g/mL) also reversed the inhibitory effect of DAMGO treated colon in a concentration dependent manner. At higher concentrations (1×10−3–3×10−3g/mL), however, this effect was lost. Motility slowed even further when naloxone and DKT were combined with noticeable disruptions in spatiotemporal patterns. Interestingly, when added alone, DKT resulted in reverse peristalsis of the pellet. In electrophysiologic studies DKT inhibited both excitatory and inhibitory junction potentials. Conclusions: DKT appears to be as effective as naloxone in restoring motility in DAMGO treated colon. These two agents, however, do not appear to have an additive effect. When used on untreated colon segments, DKT appears to cause disruptions in the intrinsic reflex circuit of the gut resulting in a disruption of neuromuscular communication. [ABSTRACT FROM AUTHOR]

Background: The purpose of the present paper was to determine the clinical and electrophysiological features of Japanese pediatric long QT syndrome (LQTS) patients with KCNQ1 mutations (LQT1). Methods: KCNQ1 mutations were analyzed in 13 Japanese pediatric patients with prolonged QT interval on electrocardiogram (ECG). These LQT1 patients were reviewed, retrospectively, for the presence of past and family histories of LQTS-related cardiac events, other complications, and their ECG findings evaluated at rest and during exercise). Results: KCNQ1 mutations were identified in eight patients (61.5%) from six unrelated families. Four missense mutations were identified in seven patients and an insertion/deletion in one. The mutations were located in the transmembrane domain in four patients and the C-terminal domain in four. Syncope did not occur in patients with the C-terminal domain mutations up to the age of 6–9 years, but family members of patients with the C-terminal domain mutations had a history of syncope in their elementary school days. Compared with a non-LQTS control group, peak heart rate (HR) on exercise and the HR increase during exercise were significantly lower in the LQT1 group (LQT1 vs control, 155 ± 16 beats/min vs 182 ± 13 beats/min, P < 0.01, 66 ± 16 beats/min vs 99 ± 24 beats/min, P < 0.01, respectively). Conclusions: The risk of LQTS-related cardiac events may not be different in pediatric LQT1 patients with C-terminal domain mutations than in patients with transmembrane domain mutations. Possible sinus node dysfunction or a poor HR response to sympathetic stimulation has been suggested in pediatric LQT1 patients. [ABSTRACT FROM AUTHOR]

Polydipsia and water intoxication have been found to be care problems in people with schizophrenia in many countries. This Japanese study measured the body fluid distribution and body fat of 80 males with long standing schizophrenia and compared this to that of 64 healthy males, using bioelectrical impedance spectrum analysis (BIS). Participants with schizophrenia exhibited significantly lower percentages of intracellular fluid and total body fluid, and significantly higher percentages of fat. Moreover, the percentage of extracellular fluid was distributed over a wider range. When the percentage body fluid was compared between the two groups by matching body mass index and body fat, intracellular fluid was significantly lower for those participants with schizophrenia. There findings suggest that nurses and other health professionals need to be very cautious when attempting to modify the excessive drinking of fluids by patients with schizophrenia. In mistakenly trying to prevent water intoxication, they may in fact be contributing to dehydration. [ABSTRACT FROM AUTHOR]

Background: The precise electrophysiological characteristics and essential effects of left-sided ablation in atrioventricular nodal reentrant tachycardia (AVNRT) with eccentric coronary sinus (CS) activation (ECSA) have not been described.Objective: The purpose of this study was to elucidate the tachycardia characteristics and essential effects of left-sided ablation in AVNRT with ECSA.Methods: Electrophysiological and ablation data were reviewed in 340 patients with all forms of AVNRT.Results: Among 360 AVNRTs in the 340 patients, there were 23 atypical AVNRTs (6%; 12 slow-slow and 11 fast-slow) in 18 (5%) patients who exhibited ECSA with the earliest retrograde atrial activation 11 +/- 5 mm inside the CS. The patients with ECSA during the tachycardia were significantly younger than those without (38 +/- 18 vs. 51 +/- 18 years; P<.01). The presence of upper (UCP) and lower common pathways (LCP) was suggested in three (17%) and 18 (100%) patients, respectively. An ablation exclusively targeting the earliest retrograde atrial activation inside the CS eliminated the tachycardias with the elimination (n = 12) or modification of the left-sided slow pathway (SP) conduction (n = 6) without any complications. The entire reentrant circuit was considered to reside on the left side in two patients (11%) because the bidirectional SP conduction was simultaneously eliminated after the ablation inside the CS.Conclusions: Atypical AVNRT with ECSA involved the left-sided SP as a retrograde limb, and the reentrant circuit was more frequently associated with evidence that suggested a UCP and LCP. Ablation exclusively targeting the earliest retrograde atrial activation inside the CS was highly effective in this entity. [ABSTRACT FROM AUTHOR]

Background: Long QT syndromes (LQTS) are inherited diseases involving mutations to genes encoding a number of cardiac ion channels and a membrane adaptor protein. The MinK protein is a cardiac K-channel accessory subunit encoded by the KCNE1 gene, mutations of which are associated with the LQT5 form of LQTS. Objective: The purpose of this study was to search for the KCNE1 mutations and clarify the function of those mutations. Methods: We conducted a genetic screen of KCNE1 mutations in 151 Japanese LQTS patients using the denaturing high-performance liquid chromatography-WAVE system and direct sequencing. In two LQTS patients, we identified two KCNE1 missense mutations, located in the MinK N- and C-terminal domains. The functional effects of these mutations were examined by heterologous coexpression with KCNQ1 and KCNH2. Results: One mutation, which was identified in a 67-year-old woman, A8V, was novel. Her electrocardiogram (ECG) revealed marked bradycardia and QT interval prolongation. Another mutation, R98W, was identified in a 19-year-old woman. She experienced syncope followed by palpitation in exercise. At rest, her ECG showed bradycardia with mild QT prolongation, which became more prominent during exercise. In electrophysiological analyses, R98W produced reduced I(Ks) currents with a positive shift in the half activation voltages. In addition, when the A8V mutation was coexpressed with KCNH2, this reduced current magnitude, which is suggestive of a modifier effect by the A8V KCNE1 mutation on I(Kr). Conclusion: KCNE1 mutations may be associated with mild LQTS phenotypes, and KCNE1 gene screening is of clinical importance for asymptomatic and mild LQTS patients. [ABSTRACT FROM AUTHOR]

Presents schedule of activities of the 5th Asian-Pacific Symposium on Cardiac Pacing and Electrophysiology at the Nippon Convention Center in Makuhari, Japan on August 1-4, 1993.