Publications by authors named "Noriyuki Hayami"

Article Synopsis
  • The study investigates the ability of near-infrared spectroscopy (NIRS) to predict the slow-flow phenomenon in patients undergoing percutaneous coronary intervention (PCI), which can lead to worse clinical outcomes.
  • A total of 179 coronary lesions from 152 patients were analyzed, revealing that the slow-flow phenomenon occurred in 7.3% of cases, with those in this group showing significantly higher lipid core burden index values.
  • NIRS was found to be a reliable tool for predicting the slow-flow phenomenon, with optimal cutoff points for acute and chronic coronary syndrome showing 100% sensitivity in predictions.
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Residual risk of atherosclerosis remains high despite the use of lipid-lowering therapy with statins. Near-infrared spectroscopy intravascular ultrasound imaging (NIRS-IVUS) can identify vulnerable plaque via the detection of lipid-rich plaque. This study aimed to reveal the clinical characteristics of patients with vulnerable plaque despite statin therapy.

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The "on-therapy range" of direct oral anticoagulants is the 90% interval of drug concentration. Previously, we reported the on-therapy range of rivaroxaban in a single-center cohort. The present study aimed to confirm the range and intraindividual reproducibility in a multicenter cohort.

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The correlation of fractional flow reserve, which is presently the gold standard for evaluating myocardial ischemia, with three-dimensional quantitative coronary analysis-based quantitative flow ratio (QFR) is well-known. This study aims to evaluate the relationship of QFR after second-generation drug-eluting stent (2nd gen-DES) implantation to clinical outcomes. A total of 61 consecutive lesions, on which 2nd gen-DES implantation was performed from October 2014 to December 2015, were analyzed.

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Chronic inflammation is known to occur in diabetes mellitus (DM) and contributes to atrial fibrosis, possible substrates for atrial fibrillation. We tested the hypothesis that dipeptidyl peptidase (DPP)-4 inhibitors prevent the formation of atrial fibrosis through their anti-inflammatory activity, beyond the effects of controlling blood glucose.DM models obtained by administration of streptozotocin (STZ) were divided into 3 groups: with PKF275-055, a DPP-4 inhibitor in group D, glibenclamide in group SU, and no additional drug in group P.

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Background: Hypertension is one of the independent risk factors for atrial fibrillation (AF). Pulmonary veins (PVs) play an important role as the substrate for AF and triggers of AF. The purpose of this study was to determine the structural remodelling of the PVs and its effect on promoting AF in hypertensive (HT) rat hearts.

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Electrical storm (ES) was observed in an 82-year-old man with recent myocardial infarction. Conventional therapy, including amiodarone, could not suppress the ES. After more than 100 electrical defibrillations, we were finally able to control the ES with the administration of landiolol.

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Background: Agents with α-2 adrenoreceptor (AR) agonistic action have reportedly suppressed tachyarrhythmias.

Methods And Results:  We hypothesized that α-2 AR agonists would have an inhibitory effect on abnormal repolarization-related ventricular tachyarrhythmias (VTs). To test this hypothesis, the effects of 2 clinically available α-2 AR agonists (dexmedetomidine and clonidine) on the occurrence of VTs were assessed in a methoxamine-sensitized rabbit model of acquired long QT syndrome (Study 1: n=45).

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Background: Anesthesia sometimes suppresses ventricular tachyarrhythmias (VT) resistant to conventional pharmacological treatment.

Methods And Results: To know (1) whether deep anesthesia inhibits abnormal repolarization-related VT and (2) if α2-adrenoreceptor (AR) agonistic action is associated with the antiarrhythmic effect of anesthetics, the incidence of VT in a rabbit model of acquired long QT syndrome using different anesthetic regimen was assessed. In Study 1 (n = 30), 15 rabbits were lightly anesthetized with ketamine (123 ± 46 mg/kg) and an α2-AR agonist, xylazine (9.

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Atrial tachycardia (AT) and atrial fibrillation (AF) were observed in a 21-year old male who had a history of patch closure for an atrial septal defect (ASD) at the age of 5 and a persistent left superior vena cava (LSVC). During electrophysiologic study, atrial extrastimuli reproducibly induced AT which spontaneously terminated or changed into AF. Electroanatomical mapping revealed focal AT arising from the floor of the proximal LSVC.

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Background: The increase in inward current, primarily L-type Ca2+ current, facilitates torsades de pointes (TdP). Because human atrial natriuretic peptide (ANP) moderates the L-type Ca2+ current, in our study it was hypothesized that ANP counteracts TdP.

Methods And Results: We tested the effect of ANP, guanosine 3', 5'-cyclic monophosphate analogue (8-bromo cGMP) and hydralazine on the occurrence of TdP in a rabbit model.

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Supraventricular tachycardia (SVT) was observed in a 13-year-old male patient with complex clinical features that included univentricular heart with single atrium, pulmonary atresia, and polysplenia syndrome. During electrophysiologic study, atrial burst stimuli reproducibly induced and terminated the SVT, while the occurrence of ventriculoatrial block did not interrupt the SVT. His bundle electrograms (HBEs) were recognized both in the anterior and posterior regions on the common atrioventricular (AV) valve annulus.

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An asymptomatic 35 year-old man was referred to our hospital because of abnormal ECG findings. The ECG showed complete right bundle branch block and left anterior hemiblock. Echocardiography revealed a moderately enlarged right ventricle (RV) and an apical aneurysm.

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The efficacy of electrical defibrillation is considered to be related to the autonomic status. In search of a possible adjunct to enhance the therapeutic performance of an implantable cardioverter-defibrillator. we investigated whether parasympathetic manipulation by cervical vagal nerve stimulation (VNS) increases defibrillation efficacy.

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This report describes a male patient with WPW syndrome who underwent surgical repair of sudden, severe mitral valve regurgitation through the posterior leaflet 20 months after successful RF catheter ablation for Kent bundle at the age of 14, and discusses the problem of valvular damage caused by this technique.

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The aim of this study was to test the hypothesis that a subendocardial arrhythmogenic focus makes the heart more susceptible to VF due to electrical interaction with the Purkinje network. Monofocal ventricular tachycardia (mVT) was created by injecting 5-microg aconitine into the left ventricular subepicardium (EPI-mVT, n = 8) or subendocardium (ENDO-mVT, n = 13) in anesthetized dogs. Despite the similar cycle length of mVT, the incidence of VF was significantly different between EPI-mVT and ENDO-mVT (100 [8/8] vs 46% [6/13], P <0.

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