記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Heart Journal (Japanese Heart Journal)  

We herein report a case of left ventricular dysfunction due to cardiac sarcoidosis following cardiac resynchronization therapy defibrillator (CRT-D) in an 87-year-old man. He presented to our hospital after receiving shock therapy while conscious. Device interrogation revealed that inappropriate shock occurred due to sinus tachycardia. Due to the setting of a low ventricular tachycardia (VT) detection rate because of a history of slow VT, increasing the VT detection rate was not feasible. After initiation of treatment with ivabradine, the sinus rate decreased and there was no recurrence of inappropriate shock during a 3-year follow-up period. Ivabradine was effective for preventing inappropriate shock due to sinus tachycardia.

DOI： 10.1536/ihj.24-323

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Atrial tachyarrhythmias (ATAs) are the primary cause of inappropriate implantable cardioverter-defibrillator (ICD) therapy in patients with idiopathic ventricular fibrillation (IVF) and are associated with decreased quality of life and increased mortality. Nonetheless, the incidence of ATAs in IVF cases has not been clarified. OBJECTIVE: The study sought to determine the incidence and clinical significance of ATAs in patients with IVF compared with those with Brugada syndrome (BrS). METHODS: Patients diagnosed with IVF or BrS and receiving ICDs in 6 hospitals were enrolled between February 1997 and July 2020 to compute data regarding the incidence of ATAs, appropriate/inappropriate ICD therapy frequency, and independent predictors of ATAs. RESULTS: Overall, 137 patients (51 in the IVF group and 86 in the BrS group) were enrolled. ATAs were detected in 22 (43.1%) patients in the IVF group and 17 (19.8%) in the BrS group (P = .006). Inappropriate ICD therapies due to ATAs were more frequently observed in the IVF group than in the BrS group (12 [23.5%] vs 7 [8.1%]; P = .020). Conversely, there was no significant difference in appropriate ICD therapies between the IVF and BrS groups (14 [27.5%] vs 23 [27.1%]; P = 1.000). Cox regression analysis revealed no predictive factors for the development of ATAs in the IVF group. CONCLUSION: ATA events were observed more frequently in patients with IVF than in those with BrS, and ATAs led to inappropriate ICD therapy in patients with IVF. Clinicians need to consider the recurrence of not only ventricular arrhythmias, but also the development of atrial arrhythmias for better management of IVF cases.

DOI： 10.1016/j.hroo.2024.09.001

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Epicardial unipolar mapping has not been thoroughly investigated in Brugada syndrome (BrS). OBJECTIVES: This study aims to examine the characteristics of epicardial unipolar potentials in BrS and investigate the differences from overt cardiomyopathy. METHODS: Epicardial mapping was performed in 8 patients with BrS and 6 patients with cardiomyopathy. We investigated the J-wave amplitudes using unipolar recordings at delayed potential (DP) sites via bipolar recordings. The repolarization time (RT) at and around the DP recording sites was measured, and maximum dispersion of the RT divided by the distance was defined as the RT dispersion index. RESULTS: Epicardial mapping at baseline revealed significantly higher J-wave amplitude with bipolar DP in patients with BrS than in patients with cardiomyopathy. J-wave amplitude ≥0.42 mV had 99.1% sensitivity and 100% specificity for diagnosing BrS. The RT dispersion index was significantly higher in patients with BrS than in patients with cardiomyopathy at baseline. In all patients with BrS, coved-type unipolar electrograms without negative T waves (short RT) appeared close to coved-type electrograms with negative T waves (long RT) at the DP recording sites after pilsicainide administration. Thus, a steep RT dispersion was observed in this region, and ventricular arrhythmias emerged from this shorter RT area in all 3 patients with BrS in whom ventricular arrhythmias were induced. CONCLUSIONS: Bipolar DP-related prominent unipolar J waves and steep repolarization gradients may be more specific for characterizing BrS than for overt cardiomyopathy. Ventricular arrhythmias in BrS are associated with a steep repolarization gradient, indicating phase 2 re-entry as a possible cause.

DOI： 10.1016/j.jacep.2024.05.012

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: In patients with Brugada syndrome, myocardial fibrosis can be identified through epicardial biopsy or cardiac magnetic resonance (CMR) imaging with late gadolinium enhancement (LGE). However, the myocardial alterations in patients with early repolarization syndrome (ERS) remain poorly elucidated. OBJECTIVE: The objective of this study was to investigate the presence of myocardial fibrosis in patients with ERS by LGE in CMR. METHODS: We retrospectively evaluated 20 patients with ERS, all of whom exhibited J waves in the contiguous 2 leads. The location of J waves was classified as in the septum (V1-V2), anterior (V3-V4), lateral (I, aVL, V5-V6), inferior (II, III, aVF), or posterior (V7-V9) regions. To compare the distribution of LGE on CMR imaging with J waves, sections on short-axis view of the left ventricle (LV) were categorized as located in the septum, anterior, lateral, inferior, and posterior regions. RESULTS: Overall, 85% of ERS patients displayed LGE, which was more prevalent in the septum and posterior regions, followed by the inferior and lateral regions. The presence or absence of J waves and LGE coincided in 61% of LV areas, whereas discordance between the distributions of J waves and LGE was observed in 38%. LGE was most frequent in the septum (75%), where its reflection in J waves may be less robust. The appearance of LGE was not associated with symptoms, electrical storm, or ventricular fibrillation occurrence during follow-up. CONCLUSION: LGE is common in patients with ERS, and the distribution of J waves and LGE coincides in approximately 60% of LV areas.

DOI： 10.1016/j.hrthm.2024.07.116

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Several signs of malignant early repolarizations have been proposed in patients with early repolarization syndrome (ERS). However, reports have challenged the efficacy of these signs in predicting future ventricular fibrillation (VF) in patients with ERS. OBJECTIVE: This study aimed to assess the predictive value of various electrocardiogram (ECG) markers for future VF events in patients with ERS. METHODS: We retrospectively evaluated the clinical characteristics of 44 patients with ERS to identify risk factors for VF during follow-up. RESULTS: After the initial event, 16 patients experienced VF (VF group), whereas 28 did not (non-VF group). The VF group had a longer QRS interval, more fragmented QRS (fQRS), and a higher T/R voltage ratio than the non-VF group. Wide J waves were more prevalent in the VF group; however, other J-wave markers did not differ between the groups. Positive late potentials recorded on signal-averaged ECGs were more frequent in the VF group. Whereas none of the patients showed spontaneous Brugada syndrome on ECG, the VF group frequently exhibited pilsicainide-induced ST-segment elevation. These ECG markers were significantly associated with the occurrence of VF during follow-up. Patients with multiple ECG factors, including QRS abnormalities (wide QRS or fQRS), wide J waves, and a high T/R ratio, had a worse prognosis than patients without multiple factors, effectively stratifying patient risk. CONCLUSION: The occurrence of VF in patients with ERS may be associated with conduction abnormalities such as QRS widening, fQRS, high T/R ratio, positive late potentials, and pilsicainide test results. Therefore, ECG factors could be useful in identifying high-risk patients.

DOI： 10.1016/j.hrthm.2024.04.101

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Early repolarization syndrome (ERS) is an idiopathic ventricular fibrillation (VF) associated with inferolateral J waves. While electrical storm (ES) in ERS is not rare, their characteristics and risk factors are not fully understood. OBJECTIVE: This study aimed to clarify the significance of ES in ERS. METHODS: We evaluated 44 patients with ERS who experienced VF/sudden cardiac death or arrhythmic syncope. We assessed clinical characteristics to identify the risk factors for ES. RESULTS: In total, 13 patients (30%) experienced ES (ES group). Of these, 11 patients (85%) experienced ES during the acute phase of initial VF episodes and 2 patients (2%) experienced ES during follow-up. VF associated with ES occurred during therapeutic hypothermia in 6 of 13 patients (46%). The J-wave voltage during therapeutic hypothermia was higher in the ES group than that in the patients without ES. Isoproterenol was used in 5 patients (38%), which decreased J-wave voltage and relieved ES. Among the clinical markers, shorter QT and QTp intervals (the interval from QRS onset to the peak of T wave), pilsicainide-induced ST elevation, and high scores on the Shanghai Score System were associated with ES. Although pilsicainide induced ST elevation in 6 of 34 patients (18%), spontaneous Brugada electrocardiographic patterns did not appear to be associated with VF. Therapeutic hypothermia was also a risk factor for acute phase ES. CONCLUSION: Patients with ERS in the ES group frequently had short QT and QTp intervals, pilsicainide-induced ST elevations, and high Shanghai Score System scores. Therapeutic hypothermia was also associated with acute phase ES.

DOI： 10.1016/j.hrthm.2024.01.016

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

Abstract

Background

Remote monitoring (RM) of cardiac implantable electrical devices (CIEDs) can detect various events early. However, the diagnostic ability of CIEDs has not been sufficient, especially for lead failure. The first notification of lead failure was almost noise events, which were detected as arrhythmia by the CIED. A human must analyze the intracardiac electrogram to accurately detect lead failure. However, the number of arrhythmic events is too large for human analysis. Artificial intelligence (AI) seems to be helpful in the early and accurate detection of lead failure before human analysis.

Objective

To test whether a neural network can be trained to precisely identify noise events in the intracardiac electrogram of RM data.

Methods

We analyzed 21 918 RM data consisting of 12 925 and 1884 Medtronic and Boston Scientific data, respectively. Among these, 153 and 52 Medtronic and Boston Scientific data, respectively, were diagnosed as noise events by human analysis. In Medtronic, 306 events, including 153 noise events and randomly selected 153 out of 12 692 nonnoise events, were analyzed in a five‐fold cross‐validation with a convolutional neural network. The Boston Scientific data were analyzed similarly.

Results

The precision rate, recall rate, F1 score, accuracy rate, and the area under the curve were 85.8 ± 4.0%, 91.6 ± 6.7%, 88.4 ± 2.0%, 88.0 ± 2.0%, and 0.958 ± 0.021 in Medtronic and 88.4 ± 12.8%, 81.0 ± 9.3%, 84.1 ± 8.3%, 84.2 ± 8.3% and 0.928 ± 0.041 in Boston Scientific. Five‐fold cross‐validation with a weighted loss function could increase the recall rate.

Conclusions

AI can accurately detect noise events. AI analysis may be helpful for detecting lead failure events early and accurately.

DOI： 10.1002/joa3.13037

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記述言語：英語  

J-GLOBAL

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記述言語：英語  

J-GLOBAL

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記述言語：英語  

J-GLOBAL

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

Abstract

Introduction

Electrical storm (ES) of ventricular tachyarrhythmias (VTAs) is an important cause of sudden death in patients with cardiac sarcoidosis (CS). VTAs in CS are associated with myocardial scarring and inflammation. However, little is known about the risk factors of ES in patients with CS and VTAs. The objective of this study is to clarify the characteristics and risk factors for the development of ES in patients with CS.

Methods

The study population included consecutive 52 patients with CS and sustained VTA. Twenty‐five out of 52 patients experienced ES. We evaluated clinical characteristics, imaging modalities, and electrocardiogram (ECG) parameters to determine the risk factors associated with ES.

Results

Half of the patients experienced VTAs as the initial symptom of sarcoidosis, and eight patients had ES as the initial VTA episode. There were no differences in cardiac imaging abnormalities between patients with and without ES. Among ECG markers, significant QRS fragmentation (odds ratio [OR]: 7.9, p = .01) and epsilon waves (OR: 12.24, p = .02) were associated with ES. Among the ventricular tachycardia (VT) characteristics, multiple morphologies of monomorphic VTs (OR: 10.9, p < .01), short VT cycle lengths (OR: 12.5, p < .01), and polymorphic VT (OR: 13.5, p < .01) were associated with ES. Bidirectional VTs were detected in 10 patients with ES and one patient without ES. Immunosuppressive therapy relieved ES in some patients.

Conclusions

ES was common in patients with CS and VTAs. Significant depolarization abnormalities that appeared as QRS fragmentation, epsilon waves, and specific VT characteristics were associated with ES.

DOI： 10.1111/jce.16156

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: J waves in the inferior or lateral leads are characteristic electrocardiographic (ECG) changes in patients with early repolarization syndrome (ERS). However, the presence of J waves in the left posterior region has not yet been evaluated. OBJECTIVE: The purpose of this study was to clarify the significance of J waves in the posterior left ventricle using leads V7-V9 and a body surface mapping (BSM) system. METHODS: Forty patients diagnosed with ERS were included. All patients exhibited J waves in either the contiguous inferior, lateral, or posterior leads. We evaluated the incidence of J waves in the inferolateral and posterior leads using a 15-lead ECG with synthesized V7-V9 and an 87-lead BSM. Additionally, we assessed the arrhythmogenicity of the posterior regions based on the morphology of the premature ventricular complexes (PVCs) associated with ventricular fibrillation (VF). RESULTS: J waves were observed in the lateral, inferior, and posterior leads of 26 (65%), 31 (78%), and 39 (97%) patients, respectively. J waves were found only in the posterior leads of 5 patients. BSM was evaluated in 9 patients, all of whom exhibited a positive area on the posterior region. PVCs associated with VF were recorded in 5 patients. Among patients with inferolateral and posterior J waves, all except 1 patient who displayed left bundle branch block morphology showed PVCs originating from the posterior left ventricular region. CONCLUSION: Posterior J waves are common in ERS patients. This abnormality can be detected using leads V7-V9 and the BSM system and may be associated with arrhythmogenesis.

DOI： 10.1016/j.hrthm.2023.08.032

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Syncope is a significant prognostic factor in patients with Brugada syndrome (BrS). However, the risk of ventricular arrhythmia in patients with nonarrhythmic loss of consciousness (LOC) is similar to that in asymptomatic patients. LOC events after implantable cardioverter-defibrillator (ICD) implantation may provide insights into underlying causes of the initial LOC episode. OBJECTIVE: The purpose of this study was to examine LOC characteristics following ICD implantation. METHODS: We retrospectively analyzed 112 patients with BrS (mean age 47 years; 111 men) who were treated with an ICD. The patients were classified into 3 groups based on symptoms at implantation: asymptomatic (35 patients); LOC (46 patients); and ventricular tachyarrhythmia (VTA) (31 patients). We evaluated the incidence and cause of LOC during long-term follow-up after ICD implantation. RESULTS: During mean follow-up of 12.2 years, 41 patients (37%) experienced LOC after ICD implantation. Arrhythmic LOC occurred in 5 asymptomatic patients, 14 LOC patients, and 16 patients with VTA. Nonarrhythmic LOC, similar to the initial episode, occurred after ICD implantation in 6 patients with prior LOC (2 with neurally mediated syncope and 4 with epilepsy). Most epileptic patients experienced LOC during rest or sleeping, and did not show an abnormal encephalogram during initial evaluation of the LOC episodes. CONCLUSION: After ICD implantation, 13% of patients had nonarrhythmic LOC similar to the initial episode. Accurate classification of LOC based on a detailed medical history is important for risk stratification, although distinguishing arrhythmic LOC from epilepsy-related LOC episodes can be challenging depending on the circumstances and characteristics of the LOC event.

DOI： 10.1016/j.hroo.2023.09.007

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Circulation Society  

Background: Various types of arrhythmia are observed in patients with cardiac amyloidosis, but the prevalence of arrhythmia has not been fully investigated. This study investigated the prevalence and treatment of arrhythmias in patients with cardiac amyloidosis before the introduction of new agents for amyloidosis, such as tafamidis. Methods and Results: Of 53 patients who were histologically diagnosed with cardiac amyloidosis at 10 centers in western Japan between 2009 and 2021, 43 who were diagnosed on the basis of immunohistochemical staining were evaluated in this study. Of these 43 patients, 13 had immunoglobulin light-chain (AL) amyloidosis and 30 had transthyretin (ATTR) amyloidosis; further, 27 had atrial tachyarrhythmia, 13 had ventricular tachyarrhythmia, and 17 had bradyarrhythmia. Atrial fibrillation (AF) was the most common arrhythmia in patients with cardiac amyloidosis (n=24; 55.8%), especially among those with ATTR amyloidosis (70.0% of ATTR vs. 23.1% of AL). Eleven (25.6%) patients were treated with a cardiac implantable device. All 3 patients with pacemakers were alive at the last follow-up (median 76.7 months; interquartile range [IQR] 4.8-146.4 months). Of the 8 patients who underwent AF ablation, there was no recurrence in 6 (75%) after a median of 39.3 months (IQR 19.8-59.3 months). Conclusions: The prevalence of various arrhythmias was high in patients with cardiac amyloidosis. AF occurred most frequently in patients with cardiac amyloidosis, especially among patients with ATTR.

DOI： 10.1253/circrep.cr-23-0022

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Ovid Technologies (Wolters Kluwer Health)  

Background

<p lang="en">The appearance of complete right bundle‐branch block (CRBBB) in Brugada syndrome (BrS) is associated with an increased risk of ventricular fibrillation. The pathophysiological mechanism of CRBBB in patients with BrS has not been well established. We aimed to clarify the significance of a conduction delay zone associated with arrhythmias on CRBBB using body surface mapping in patients with BrS.

</p> Methods and Results

<p lang="en">Body surface mapping was recorded in 11 patients with BrS and 8 control patients both with CRBBB. CRBBB in control patients was transiently exhibited by unintentional catheter manipulation (proximal RBBB). Ventricular activation time maps were constructed for both of the groups. We divided the anterior chest into 4 areas (inferolateral right ventricle [RV], RV outflow tract [RVOT], intraventricular septum, and left ventricle) and compared activation patterns between the 2 groups. Excitation propagated to the RV from the left ventricle through the intraventricular septum with activation delay in the entire RV in the control group (proximal RBBB pattern). In 7 patients with BrS, excitation propagated from the inferolateral RV to the RVOT with significant regional activation delay. The remaining 4 patients with BrS showed a proximal RBBB pattern with the RVOT activation delay. The ventricular activation time in the inferolateral RV was significantly shorter in patients with BrS without a proximal RBBB pattern than in control patients.

</p> Conclusions

<p lang="en">The CRBBB morphology in patients with BrS consisted of 2 mechanisms: (1) significantly delayed conduction in the RVOT and (2) proximal RBBB with RVOT conduction delay. Significant RVOT conduction delay without proximal RBBB resulted in CRBBB morphology in patients with BrS.

</p>

DOI： 10.1161/jaha.122.028706

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Women have longer baseline QT intervals than men. Because previous studies showed that testosterone and 5α-dihydrotestosterone shorten the ventricular action potential duration (APD) in animal models, differential testosterone concentrations may account for the sex differences in QT interval. OBJECTIVE: The purpose of this study was to test the hypothesis that testosterone shortens the APD in Langendorff-perfused rabbit ventricles. METHODS: We performed optical mapping studies in hearts with or without testosterone administration. Acute studies included 26 hearts using 2 different protocols, including 17 without and 9 with atrioventricular (AV) block. For chronic studies, we implanted testosterone pellets subcutaneously in 7 female rabbits for 2-3 weeks before optical mapping studies during complete AV block. Six rabbits without pellet implantation served as controls. RESULTS: The hearts in the acute studies were paced with a pacing cycle length (PCL) of 200-300 ms and mapped at baseline and after administration of 1 nM, 10 nM, 100 nM, and 3 μM of testosterone. There was no shortening of APD80 at any PCL. Instead, a lengthening of APD80 was noted at higher concentrations. There were no sex differences in testosterone responses. In chronic studies, heart rates were 136 ± 5 bpm before and 148 ± 9 bpm after (P = .10) while QTc intervals were 314 ± 9 ms before and 317 ± 99 ms after (P = .69) testosterone pellet implantation, respectively. Overall, ventricular APD80 in the pellet group was longer than in the control group at 300- to 700-ms PCL. CONCLUSION: Testosterone does not shorten ventricular repolarization in rabbit hearts.

DOI： 10.1016/j.hrthm.2022.06.012

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

Constant pacing (S1-S1: 520 ms) from the right atrial appendage (RAA) during reentrant atrial tachycardia originating from the atrioventricular node vicinity. RA-FW 1-2 was constantly captured antidromically. However, the earliest atrial activation site (EAAS = His1-2) was orthodromically (red circle) and antidromically (blue square) captured at a ratio of 3:1. The electrogram morphology at the EAAS was different between orthodromically and antidromically electrograms captured during pacing. Moreover, the interval between the S1 and orthodromically captured electrogram was gradually prolonged.

DOI： 10.1002/joa3.12702

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その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/joa3.12702

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Sympathetic nerve activity, heart rate (HR), and blood pressure (BP) all have very low frequency (VLF), low frequency (LF), and high frequency (HF) oscillations. OBJECTIVE: The purpose of this study was to test the hypothesis that the frequency spectra of subcutaneous nerve activity (ScNA), stellate ganglion nerve activity (SGNA), HR, and BP are important to cardiac arrhythmogenesis. METHODS: We used radiotransmitters to record SGNA, ScNA, HR, and BP in 6 ambulatory dogs and determined the dominant frequency and paroxysmal atrial tachyarrhythmias (PATs) episodes in 3-minute windows over a 24-hour period. RESULTS: The frequency spectra determined in ScNA reflected that in SGNA. HF oscillations were present in both ScNA and SGNA at all time but could be overshadowed by the much larger LF and VLF burst activities. The dominant frequency could occur in any of the 3 frequency bands. There were circadian variations with more frequent occurrences of HF oscillations at night. HF oscillations in HR and BP matched HF oscillations in SGNA and ScNA. PATs occurred only when dominant frequencies of SGNA and ScNA were in the LF and VLF bands. CONCLUSION: HF oscillations in BP and HR correlate with HF oscillations in sympathetic nerve activity and are present at all time. HF oscillations can be overshadowed by the much larger LF and VLF burst activities. PATs occur only when LF or VLF, but not when HF, is the dominant frequency. The frequency spectra determined in ScNA reflect that in SGNA.

DOI： 10.1016/j.hrthm.2020.11.023

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

BACKGROUND: Concomitant apamin-sensitive small conductance calcium-activated potassium current (IKAS) activation and sodium current inhibition induce J-wave syndrome (JWS) in rabbit hearts. Sudden death in JWS occurs predominantly in men at night when parasympathetic tone is strong. OBJECTIVE: The purpose of this study was to test the hypotheses that acetylcholine (ACh), the parasympathetic transmitter, activates IKAS and causes JWS in the presence of ajmaline. METHODS: We performed optical mapping in Langendorff-perfused rabbit hearts and whole-cell voltage clamp to determine IKAS in isolated ventricular cardiomyocytes. RESULTS: ACh (1 μM) + ajmaline (2 μM) induced J-point elevations in all (6 male and 6 female) hearts from 0.01± 0.01 to 0.31 ± 0.05 mV (P<.001), which were reduced by apamin (specific IKAS inhibitor, 100 nM) to 0.14 ± 0.02 mV (P<.001). More J-point elevation was noted in male than in female hearts (P=.037). Patch clamp studies showed that ACh significantly (P<.001) activated IKAS in isolated male but not in female ventricular myocytes (n=8). Optical mapping studies showed that ACh induced action potential duration (APD) heterogeneity, which was more significant in right than in left ventricles. Apamin in the presence of ACh prolonged both APD at the level of 25% (P<.001) and APD at the level of 80% (P<.001) and attenuated APD heterogeneity. Ajmaline further increased APD heterogeneity induced by ACh. Ventricular arrhythmias were induced in 6 of 6 male and 1 of 6 female hearts (P=.015) in the presence of ACh and ajmaline, which was significantly suppressed by apamin in the former. CONCLUSION: ACh activates ventricular IKAS. ACh and ajmaline induce JWS and facilitate the induction of ventricular arrhythmias more in male than in female ventricles.

DOI： 10.1016/j.hrthm.2020.07.036

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Heart Journal (Japanese Heart Journal)  

In order to prevent ischemic stroke, it is important to identify and treat patients with atrial fibrillation (AF) who do not consult a doctor in a medical institution. The aim of this study was to determine the consultation rate at medical institutions for patients with AF in group medical examinations conducted in a city in western Japan. Of 6101 examinees of group medical examinations (40 years of age or older) conducted in Ibara City, Okayama Prefecture, Japan, from 2012 to 2014, 4338 participants (71.1%) who were evaluated by electrocardiogram (ECG) gave written informed consent and responded to surveys in the form of questionnaires through a personal interview conducted by nurses were included in the Ibara-AF study. A cumulative total of 82 subjects were diagnosed as having AF by ECG (prevalence of AF = 1.89%), and 51 individuals had AF during the three-year period.15 (29.4%) of the 51 patients with AF did not regularly visit medical institutions. Among them, 46.7% (n = 7) and 53.3% (n = 8) of the patients were symptomatic and asymptomatic, respectively, and 73.3% of the patients had a CHADS2 score of more than one point. There were no significant differences in patients' characteristics between regular and non-regular visit groups. In conclusion, about one-third of the patients with AF did not regularly see a doctor in a medical institution and most of them had a CHADS2 score of more than one point in a Japanese rural area. Educating the public about the risks of AF is required.

DOI： 10.1536/ihj.19-062

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Ovid Technologies (Wolters Kluwer Health)  

Background

<p lang="en"> A drug provocation test using a sodium channel blocker ( SCB ) can unmask a type 1 ECG pattern in patients with Brugada syndrome. However, the prognostic value of the results of an SCB challenge is limited in patients with non–type 1 ECG . We investigated the associations of future risk for ventricular fibrillation with SCB ‐induced ECG changes and ventricular tachyarrhythmias ( VTA s).

</p> Methods and Results

<p lang="en"> We administered intravenous pilsicainide to 245 consecutive patients with Brugada syndrome (181 patients with spontaneous type 1 ECG , 64 patients with non–type 1 ECG ). ECG parameters before and after the test and occurrence of drug‐induced VTA s were evaluated. During a mean follow‐up period of 113±57 months, fatal VTA events occurred in 31 patients (sudden death: n=3, ventricular tachycardia/ ventricular fibrillation : n=28). Symptomatic patients and spontaneous type 1 ECG were associated with future fatal arrhythmic events. Univariable analysis of ECG parameters after the test showed that long PQ and QRS intervals, high ST level, and SCB ‐induced VTA s were associated with later VTA events during follow‐up. Multivariable analysis showed that symptomatic patients, high ST level (V1) ≥0.3  mV after the test, and SCB ‐induced VTA s were independent predictors for future fatal arrhythmic events (hazard ratios: 3.28, 2.80, and 3.62, 95% confidence intervals: 1.54–7.47, 1.32–6.35, and 1.64–7.75, respectively; P &lt;0.05).

</p> Conclusions

<p lang="en"> SCB ‐induced VTA s and ST ‐segment augmentation are associated with an increased risk of the development of ventricular tachycardia/ ventricular fibrillation events during follow‐up in patients with Brugada syndrome.

</p>

DOI： 10.1161/jaha.118.008617

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Circulation Society  

BACKGROUND: Clinical and experimental studies have shown the existence of an arrhythmogenic substrate in the right ventricular outflow tract (RVOT) in patients with Brugada syndrome (BrS). To evaluate the importance of the RVOT, we evaluated the activation pattern of induced ventricular tachyarrhythmias using body surface mapping (BSM) in patients with BrS. METHODS AND RESULTS: We examined 14 patients with BrS in whom ventricular tachyarrhythmias were induced by programmed electrical stimulation. The 87-lead BSM was recorded during induced ventricular tachyarrhythmias, and an activation map and an isopotential map of QRS complexes every 5 ms were constructed to evaluate the activation pattern of ventricular tachyarrhythmias. BSM during 20 episodes of ventricular tachyarrhythmias induced at the RVOT showed that repetitive excitation was generated at the RVOT and propagated to the inferior RV and left ventricle, and then returned to the RVOT. Polymorphic QRS change during ventricular tachyarrhythmias was associated with migration of the earliest activation site and rotor. BSM during 4 episodes of ventricular fibrillation (VF) showed that the excitation front moved randomly with formation of multiple wavefronts. CONCLUSIONS: Programmed stimulation initiated repetitive firing from the RVOT. Migration and competition of the earliest activation site and rotor and local conduction delay changed the QRS morphology. Degeneration of the reentrant circuit into multiple wavefronts resulted in VF. (Circ J 2016; 80: 1734-1743).

DOI： 10.1253/circj.cj-16-0124

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Although numerous studies have shown an association between a patent foramen ovale (PFO) and cryptogenic cerebrovascular accidents (CVA), there has been no definitive control study that demonstrated the benefit of percutaneous device closure of a PFO compared to medical therapy in patients with CVA. Additionally, few clinical data exist for Japanese patients in this field. We demonstrate the initial experiences in catheter closure of a PFO as secondary prevention of CVA in Japan. Catheter closure of a PFO was attempted in 7 patients who were diagnosed with cryptogenic CVA. Mean age at the procedure was 54 ± 19 years. The presence of spontaneous interatrial right-to-left shunts was demonstrated by transesophageal contrast echocardiography without Valsalva maneuver in all of the patients. Amplatzer Cribriform device (n = 4) or Amplatzer PFO Occluder (n = 3) was used for the procedure and was successfully deployed. Device-related complications were not observed at the time of the procedure or during the follow-up period (mean period of 16 ± 9 months). Catheter closure of a PFO could be safely performed with Amplatzer Cribriform or Amplatzer PFO Occluder. This procedure may contribute to prevention of recurrent cryptogenic CVA in Japanese patients.

DOI： 10.1007/s12928-013-0193-9

PubMed

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その他リンク： http://link.springer.com/article/10.1007/s12928-013-0193-9/fulltext.html

記述言語：英語  

DOI： 10.1016/S0735-1097(13)61914-2

Web of Science

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

This study investigated the effect of fractional flow reserve (FFR) after stent implantation on clinical outcomes. Pressurewire measurements and follow-up data were obtained after stent implantation. Regarding the end point, target lesion revascularization (TLR) occurred in 11 patients (15.9%). Patients with TLR had higher frequencies of multiple stenting (54.5 vs. 19.0%, p = 0.01), lower post-interventional FFRs (0.84 vs. 0.88, p = 0.01), and longer stent lengths (42.20 vs. 27.69 mm, p = 0.01) than patients without TLR. The post-interventional FFR cutoff for TLR was 0.79, although this value had a weak discriminatory ability. However, multivariate analysis did not show any significant independent predictors of TLR (odds ratio 6.33; confidence interval 0.75-53.4, p = 0.09). Post-interventional FFR values were not significantly associated with TLR when a sub-analysis was performed in patients who underwent only drug-eluting stent (DES) implantation. It was difficult to achieve post-interventional FFRs of 0.9 or greater. DES implantation eliminated the effect of post-interventional FFR on TLR. Post-interventional FFR was not able to predict TLR in the present study.

DOI： 10.1007/s12928-012-0147-7

PubMed

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その他リンク： http://link.springer.com/article/10.1007/s12928-012-0147-7/fulltext.html

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Angiography is not always an accurate indicator of physiologically significant stenosis. We examined the usefulness of functional evaluation of coronary stenosis severity by determining the fractional flow reserve (FFR) using a pressure wire in patients who received hemodialysis with angiographically intermediate lesions. We recruited 44 patients with intermediate lesions; of these, 22 were undergoing hemodialysis while 22 were not. Quantitative coronary angiography (QCA) was performed to measure the minimal lumen diameter (MLD) and calculate the percent diameter stenosis (%DS). The FFR was calculated as the ratio of the coronary pressure at the distal stenotic site to the mean aortic pressure during maximum hyperemia. In each group, we investigated the relationship between the FFR and %DS and FFR and MLD. The patients in the hemodialysis group were significantly younger and had more calcified and type B2/C lesions than those in the non-dialysis group. Although the FFR was correlated with both %DS (r = 0.71, p < 0.01) and MLD (r = 0.58, p < 0.01) in the non-dialysis group, the FFR was not correlated with either MLD or %DS in the hemodialysis group. In the hemodialysis group, there was a discordance between the QCA- and FFR-based assessments of the severity of coronary stenosis. In patients receiving hemodialysis, both anatomical and functional assessments should be conducted to determine the physiological significance of the stenosis accurately.

DOI： 10.1007/s12928-011-0061-4

PubMed

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その他リンク： http://link.springer.com/article/10.1007/s12928-011-0061-4/fulltext.html

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記述言語：英語   出版者・発行元：(一社)日本成人先天性心疾患学会  

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