Therapeutic Research

2023年8月に発足したプロジェクトInnovation for NEW HOPEが開催したシンポジウム「難病の診断と治療の今と未来 みんなで支え合える社会を目指して」では,難病診断・治療の現状や実体験,現状の政策を踏まえた難病対策のあるべき未来についての講演,およびパネルディスカッションが行われた.本稿では,水澤英洋氏(国立精神・神経医療研究センタ-/東京科学大学)による講演について紹介する.

Introduction: It has been revealed that Remote Monitoring Systems(RMS) enables early detection of arrhythmic events and device malfunctions, resulting reduction of our workload and faster diagnosis. However, our institution has experienced cases where RMS alerts missed these events. These cases highlight the need to assess the system's effectiveness and limitations. This study aims to evaluate the alert detection performance and to identify limitations in RMS analysis using follow –up patient data. Methods: We analyzed data from 700 patients under follow –up at our institution between March 2022 to March 2024. Among these, 133 cases were identified as ones where arrhythmic events or device malfunctions were confirmed without RMS alerts. These cases were categorized and analyzed by event types. Results: Of the 133 cases, 54.1% were related to arrhythmias such as NSVT and AF, 25.6% involved device malfunctions like undersensing and pacing failure, and 12.0% were related to heart failure events, such as thoracic impedance changes and increased PVCs. Additionally, 27.8% were identified facility through IEGM(Intracardiac Electrogram) analysis. Discussion: The primary causes of undetected alerts were the lack of specific alert parameters and inappropriate alert settings. Variations in alert specifications across manufacturers and models increase the risk of missing critical clinical events if not fully understanding these limitations. It is also essential to adjust alert settings based on individual patient conditions, such as post –AF ablation or post –TAVI, to improve detection threshold. Regular reviews of both device and alert settings during patient follow –up are crucial to ensure timely accurate detection. Conclusion: The RMS alert function has inherent limitations. To improve the accuracy and safety of device management, it is necessary to optimize alert settings and incorporate IEGM analysis alongside RMS alerts, enhancing the detection threshold of significant clinical events.

2019 年6 月から2021 年12 月までのRMS未送信患者に対して送信率改善目的に電話介入を施行したところ,未送信の原因として入院が最も多かった.入院中の未送信期間中に重大なイベントが見過ごされている症例を経験したため,改善策を検討することとした.

高齢者の経静脈ペ-スメ-カ(以下TV –PM)交換術は新規植込みに対して感染リスクが上昇すると報告されている1, 2).当院では,高齢のペ-スメ-カ電池消耗患者に対してリ-ドレスペ-スメ-カ(以下LP)の追加留置術(ダブルデバイス)を施行する頻度が増えている.今回,TV–PM(ELA社製Symphony SR2550,Vリ-ド:Medtronic 社製5054–52)電池消耗患者に対してAveirVR(以下Aveir)の追加留置術を施行し,相互干渉と思われる症例を経験した.TV–PMの設定はモ-ドVVI50,出力2.5 V/0.35ms,感度2.5 mV Bipolar.LP設定はモ-ドVVI60,出力2.5 V/0.4 ms,感度2.0 mV Bipolarであったが,Aveirから閾値測定時に1.0 V でCaptureLossするもTV–PMからのBack Up Pacingが抑制された.ダブルデバイス患者におけるTV–PMとLPの相互干渉を明らかにするため,水槽を用いた体外実験を施行した.

Implantation of a cardiac resynchronization therapy defibrillator(CRT –D) in heart failure patients with reduced left ventricular ejection fraction and persistent left superior vena cava(PLSVC)may be difficult due to anatomical variation. We report a case of a 59–year –old man with PLSVC and heart failure due to left ventricular non –compaction who underwent a CRT–D implantation. Preoperative computed tomography(CT) showed a PLSVC, a markedly dilated coronary sinus and absent innominate vein. The right –side implantation was performed and the right ventricular lead was implanted without difficulty; however, the coronary venous lead insertion into the postero –lateral branch was challenging because the target branch was not visible by coronary angiography or venography. The horizontal views and three –dimensional images from contrast –enhanced CT were carefully examined, confirming the flat –shaped entrance of the postero–lateral branch running parallel to the main PLSVC and located near the tricuspid valve annulus. Subsequently, a guiding inner –catheter was successfully advanced into the postero –lateral branch under intracardiac electrogram guidance with a decapolar electrode catheter and a coronary venous lead was finally implanted without any complications. This case highlighted the usefulness of combined guidance with constant –enhanced CT and electrode catheter for CRT–D implantation.

In hemodialysis patients, leadless pacemaker is recommended to reduce the risk of device infection and central venous stenosis. However, in the case of acute heart failure, the possibility of atrial mechanical sensing failure was suggested. A 93 –year–old woman with hemodialysis has had Leadless VDD pacemaker implantation for complete atrioventricular block 5 months before admission. She was transported by ambulance to our hospital complaining of dyspnea. On admission she showed marked pulmonary edema and emergent hemodialysis was performed. Her electrocardiogram showed atrio –ventricular dyssynchrony, then 1 hour after the commencement of hemodialysis atrio –ventricular synchrony was recovered and she became hemodynamically stable. In comparison with the echocardiogram of 6 days before admission, she showed markedly reduced dyssynchronous A –wave of the transmitral flow velocity on admission. The restoration of the A –wave according to the volume reduction by the emergent hemodialysis was considered to lead to the improvement of the atrial mechanical sensing by increasing the A4 signal.

Introduction: We report a case in which the pacemaker’s tachycardia prevention function led to the suppression of atrial fibrillation(AF).( Edora 8 DR–T®)Case Presentation: 96–year –old male. Primary diseases: Bradycardia –tachycardia syndrome, AF. Pacemaker implantation was performed in July 2022. Case Details: Initially, with the DDD–CLS setting, the pacemaker operated at a rate favoring the atrial pacing(Ap rate), with the atrial rate remaining around the basic rate of 60–70 bpm(Fig. 1). Starting in January 2023, frequent mode switching occurred, and the Ap rate was 1% , with both the atrial rate and AF burden being high. During a follow – up visit in August of the same year, the mode was changed from CLS to DDDR, with the overdrive function turned on, converting to DDDR+(Fig. 2). After the setting change, the average atrial rate increased to 80–90 bpm, with the pacing rate rising to 99%(Fig. 3).Discussion: The CLS mode is typically used as a rate response function, but in this case, it was also intended to suppress AF1), though AF still occurred. Changing from DDD–CLS to DDDR+ resulted in an increase in the atrial pacing rate, which helped suppress AF caused by premature atrial contractions(PACs). This suggests that the overdrive function was effective in preventing AF triggered by PACs. Changing to other settings may also lead to a positive shift in outcomes. Conclusion: This case demonstrates that changing the pacemaker settings from DDD–CLS to DDDR+ can effectively suppress atrial fibrillation.

Background: The relationship between the degree of change in the left ventricular ejection fraction and physical function in patients with heart failure remains unclear. This study aimed to assess the associations between physical characteristics, change in the left ventricular ejection fraction, and physical function in response to heart failure treatment. 　　Methods: In this retrospective cohort analysis, patients with heart failure aged ≧65 years who underwent cardiopulmonary exercise testing were classified into three groups based on the change in the left ventricular ejection fraction(recovered[HFrecEF], worsened [HFworEF], and unchanged[HFuncEF]). Cardiopulmonary exercise testing measured the peak oxygen uptake and minute ventilation. 　　Results: Overall, 191 patients were included. Age, height, and weight did not differ significantly between the groups. The HFworEF group showed significant deterioration in blood urea nitrogen, creatinine, brain natriuretic hormone, and estimated glomerular filtration levels. Beta‒blocker use was significantly higher in the HFrecEF group than in other groups. The three groups differed significantly in peak oxygen uptake(HFrecEF, median 806.5; HFworEF, 600.0; and HFuncEF, 749.0; p<0.05), heart rate(HFrecEF, 121.0; HFworEF, 100.0; and HFuncEF, 107.0; p<0.05), and minute ventilation(HFrecEF, 35.3; HFworEF, 25.8; and HFuncEF, 34.0; p<0.01). The peak oxygen uptake(ρ=0.252) and minute ventilation(ρ=0.184)were not correlated with the change in the left ventricular ejection fraction(all p<0.01). 　　Conclusions: The HFworEF group had poor heart and kidney function and low physical function. Change in the left ventricular ejection fraction was not correlated with physical function.

超音波画像診断は,視認性の低い超音波画像を用いて診断を行うため,超音波診断の質が診断者の専門的知識や経験に大きく依存するという問題点がある.この問題点を解決するには,超音波画像の視認性を高め診断しやすい画像へと変換できる手法が必要である.近年,深層学習は画像処理やパタ-ン認識において高い性能を示し,深層学習を医療分野に応用することで画像診断の迅速化と精度向上が期待されている.本研究では,従来のpix2pixに加え,Transformerブロックを組み込んだTranspix2pixの2種類の深層学習を用いて視認性の低い超音波画像をX線CT画像に類似した視認性が高い画像へと変換した.また,2 種類の深層学習から得られた画像を定量的に評価するための画質評価方法(Peak Signal to Noise Ratio:PSNR, Structural SIMilarity:SSIM)の比較も行った.結果として,Transpix2pixがpix2pix を上回る評価値を示し,より高精度な画像変換が可能であることを示した.本手法は超音波画像診断の質を向上させ,診断者への依存を減らす効果が期待される.