Publications by authors named "Ryota Yamauchi"

Background: Visualizing the specific regions where atrial fibrillation (AF) is maintained is crucial for effective treatment, but it remains challenging in clinical practice. We aimed to address this challenge by developing a mapping approach focused on the cycle length (CL) and its gradient (CL-gradient).

Methods: In 105 patients undergoing initial ablation for persistent AF, pre-ablation CARTOFINDER data were utilized to create maps based on three indicators: (1) CL, the atrial frequency during AF calculated using CARTOFINDER; (2) Short CL, encompassing CLs within 5 ms of the minimum CL; and (3) CL-gradient, the CL range within a 6 mm radius.

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  • A study investigated the link between high uric acid levels (hyperuricemia) and the recurrence of arrhythmia after catheter ablation for paroxysmal atrial fibrillation (AF), finding that hyperuricemia may increase the risk of AF returning.
  • The research divided patients into two groups based on their uric acid levels and discovered that those with hyperuricemia had a higher alcohol consumption rate and a lower rate of remaining free from AF after treatment.
  • Key factors predicting AF recurrence included hyperuricemia, alcohol consumption of 20g/day or more, female gender, and higher brain natriuretic peptide levels, suggesting that both hyperuricemia and alcohol intake independently influence AF recurrence risks
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Background: The fibrosis-5 (FIB-5) index is a noninvasive marker for assessing the progression of liver fibrosis and predictor in patients with heart failure (HF). This study investigated the association between the FIB-5 index and response to cardiac resynchronization therapy (CRT) and evaluated its predictive value for prognosis.

Methods: In total, 203 patients who underwent CRT/CRT-defibrillator (CRT-D) implantation were retrospectively included.

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Introduction: Intrinsic antitachycardia pacing (iATP) is a novel automated antitachycardia pacing (ATP) that provides individual treatment to terminate ventricular tachycardia (VT). However, the clinical efficacy of iATP in comparison with conventional ATP is unknown. We aim to compare the termination rate of VT between iATP and conventional ATP in patients with implantable cardioverter-defibrillators using a unique setting of different sequential orders of both ATP algorisms.

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  • The study investigated cardiac resynchronization therapy (CRT) response times, comparing early (1 year) and delayed (3 years) effects in 110 patients.
  • 71% of patients showed an early response, while 38% of the early non-responders eventually exhibited a delayed response; however, non-responders had worse health outcomes overall.
  • Key predictors for delayed responses included the time since initial heart failure hospitalization, incorrect lead placement in the heart, and shorter pre-QRS durations.
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  • Functional mitral regurgitation (FMR) is common in patients with atrial fibrillation (AF) and can worsen heart failure (HF), prompting a study of its effects on catheter ablation outcomes in HF patients.
  • In a study of 280 patients with HF and nonparoxysmal AF, FMR cases decreased significantly from 54.6% at baseline to 25% after one year following ablation, with many experiencing a reduction in severity.
  • Most patients (97.9%) maintained sinus rhythm after a year, and those with improved FMR showed better cardiac parameters compared to those without improvement, indicating a positive feedback loop for heart function after ablation.
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Background: Few studies have reported on the quantitative evaluation of autonomic nerve modification after balloon ablation. Therefore, this study aimed to evaluate the effects of cryoballoon and hotballoon ablations on the autonomic nervous system (ANS) and their relationship with prognosis.

Methods: We included 234 patients who underwent cryoballoon ablation (n = 190) or hotballoon ablation (n = 44) for paroxysmal atrial fibrillation.

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Deep septal ventricular pacing is a recently developed physiological pacing modality with good efficacy; however, it has a potential risk of unusual complications. Here, we report a patient with pacing failure and spontaneous, complete lead dislodgement after >2 years of deep septal pacing, possibly caused by systemic bacterial infection and specific lead behavior in the septal myocardium. This case report may implicate a hidden risk of unusual complications in deep septal pacing.

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Brown tumors are rare destructive bone lesions caused by hyperparathyroidism. As their clinical symptoms, radiographic findings, and laboratory results closely mimic those of metastatic tumors or multiple myeloma, the diagnosis may often be mistaken. We report a case of a 61-year-old woman with brown tumors in both femurs due to parathyroid carcinoma.

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  • The study examined how coexisting sick sinus syndrome (SSS) affects the success of catheter ablation (CA) in treating atrial fibrillation (AF) through a large-scale registry involving over 5,000 patients.
  • Findings showed no significant differences in AF-free survival rates between patients with SSS and those without, indicating that SSS does not negatively impact the effectiveness of CA.
  • Although 48 patients with SSS needed pacemakers, which correlated with AF recurrence, the majority (85.3%) did not require one within three years post-ablation, suggesting that most patients with SSS can have successful outcomes.
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Background And Objectives: Mitral isthmus (MI) ablation for mitral flutter is technically difficult, and incomplete block line is not uncommon. The objective of this study is to investigate the effect of the ridge line of left pulmonary vein isolation (LPVI) from left atrial appendage (LAA) on completion rate of mitral isthmus (MI) block line and recurrence rate of atrial tachycardia (AT) or atrial flutter (AFL) after the first MI ablation.

Methods: We identified 611 patients who underwent first MI ablation for mitral flutter during the study period.

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  • The study investigates the relationship between atrial defibrillation threshold (ADFT) and the recurrence of atrial tachyarrhythmia in patients undergoing catheter ablation for non-paroxysmal atrial fibrillation (AF).
  • A total of 368 patients were categorized into low ADFT (<20 J) and high ADFT (≥20 J) groups, revealing that the high ADFT group had a significantly higher rate of AF recurrence (30.6% vs. 16.7%) over a 2.6-year follow-up period.
  • The findings suggest that a high ADFT is a notable risk factor for AF recurrence specifically in patients with long-standing persistent AF, while it does not
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Although minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is the most common procedure in minimally invasive spine stabilization (MISt), details of the technique remain unclear. This technical report shows the mid-long-term clinical outcomes in patients who underwent posterior oblique square decompression (POSDe) with the three-step wanding technique of tubular MIS-TLIF for degenerative lumbar disease. Tubular MIS-TLIF (POSDe) was performed on 50 patients (males, 19; age, 69.

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Limited data exist on the prevalence and prognosis of isolated posterior ST-segment elevation acute myocardial infarction (STEMI), revealed with a posterior chest lead. Furthermore, the utility of a synthesized-V lead in the diagnosis of STEMI is unclear; therefore, we aimed to evaluate its usefulness. We enrolled 142 consecutive patients with STEMI with the culprit lesion on the left circumflex artery (STEMI-LCx) undergoing percutaneous coronary intervention (PCI) between January 2009 and December 2019.

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Background: The relationship between nutritional status and the incidence or prognosis of atrial fibrillation (AF) has been reported, but no studies have described the relationship between the outcomes of AF catheter ablation (CA) and nutritional status as assessed by various scoring tools. We aimed to verify the hypothesis that preoperative nutritional status is associated with arrhythmia recurrence after CA for AF.

Methods and results: We evaluated 913 patients (age, 67±10 years; men, 72%; paroxysmal AF, 56%) who underwent CA for AF between November 2011 and November 2017.

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Low body mass index (BMI) is a predictor of adverse events in patients with ST-elevated myocardial infarction (STEMI) in Western countries. Because the average BMI of Asians is significantly lower than that of the Western population, the appropriate cut-off BMI value and its role in long-term mortality are unclear in Asian patients. Between January 2006 and December 2017, 1215 patients who underwent percutaneous coronary intervention (PCI) for acute STEMI and were alive at discharge (mean age, 67.

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Objective: To clarify the association of detailed angiographic findings with in-hospital outcome after primary percutaneous coronary intervention (p-PCI) for ST-elevation myocardial infarction (STEMI) in Japan.

Background: Data regarding the association of detailed angiographic findings with in-hospital outcome after STEMI are limited in the p-PCI era.

Methods: Between January-2004 and December-2018, 1735 patients with STEMI (mean age, 68.

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Background: Although short-term mortality in ST-elevation myocardial infarction (STEMI) has improved, data is limited regarding very long-term mortality and concomitant clinical events in STEMI survivors who undergo primary percutaneous coronary intervention (p-PCI). This study aimed to evaluate these parameters at 15 years and to determine the predictors of 15-year mortality in these patients.

Methods: The study endpoints were all-cause mortality and cardiac mortality at 15 years.

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Knowledge of the long-term prognosis (>10 years) and mortality predictors of ST-elevation myocardial infarction (STEMI) patients who have undergone primary percutaneous coronary intervention (p-PCI) is scarce. Therefore, this study evaluated the long-term prognosis and determined the predictors of long-term outcomes for STEMI patients after p-PCI. Between January, 2006 and December, 2010, we collected data and analyzed 459 consecutive patients with acute STEMI who underwent p-PCI and were discharged from the hospital (mean age, 66.

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Aims: We aimed to examine the benefits of catheter ablation in patients with non-paroxysmal atrial fibrillation (AF) accompanied by heart failure (HF) with preserved ejection fraction (HFpEF), in comparison with the benefits in patients with AF accompanied by HF with reduced ejection fraction (HFrEF) or patients with no HF.

Methods And Results: From 1173 consecutive patients undergoing catheter ablation, 502 with non-paroxysmal AF were divided into three groups: no history of HF [plasma B-type natriuretic peptide (BNP) <100 pg/mL and no HF hospitalization; n = 125], HFpEF [left ventricular (LV) EF ≥50%; n = 293], and HF with midrange EF (HFmrEF) + HFrEF (LVEF <50%; n = 84) groups. The endpoints were AF recurrence at 1 year, changes in symptomatic and image-based functional status, and changes in BNP levels from baseline to 1 year.

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Objective The popularity of primary percutaneous coronary intervention (p-PCI) for ST-elevation myocardial infarction (STEMI) has increased over the past decades. Despite improvements in in-hospital mortality rates, it is clinically important to investigate the prognoses after discharge. However, data on the mode of death and prognostic factors are limited.

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Ossification of the posterior longitudinal ligament (OPLL) within the spinal canal sometimes leads to severe myelopathy. Teriparatide (TPD) is a recombinant human parathyroid hormone (PTH) (1-34), which promotes osteogenesis of mesenchymal stem cells (MSCs) via PTH 1 receptor (PTH1R). Although ligamentum flavum (LF)-MSCs from patients with OPLL have a high osteogenic potency, the effect of TPD on them remains unknown.

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