Publications by authors named "Yutaka Otsuji"

Basic mechanism of ventricular functional mitral regurgitation (FMR) is subvalvular tethering. Left ventricular (LV) dilatation, in association with mitral valve (MV) annular dilatation, causes outward displacement of papillary muscles (PMs), which abnormally pulls or tethers MV leaflets, resulting in MV tenting, reduction in leaflets coaptation and MR. Because surgical annuloplasty does shorten distance between anterior and posterior MV annuli to improve coaptation but does not address this subvalvular tethering, ventricular FMR frequently persists or recurs in the chronic stage after surgical annuloplasty.

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Background: Patients with only moderate atrial secondary mitral regurgitation (asMR) frequently develop heart failure (HF). Mechanisms of HF with moderate asMR and the impact of mild asMR remain unclarified. Although mild/moderate primary mitral regurgitation is compensated by left ventricular (LV) dilatation, the LV is not dilated in asMR.

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Background: Topological data analysis (TDA) can generate patient-patient similarity networks by analyzing large, complex data and derive new insights that may not be possible with standard statistics.

Objectives: The purpose of this paper was to discover novel phenotypes of chronic primary mitral regurgitation (MR) patients and to analyze their clinical implications using network analysis of echocardiographic data.

Methods: Patients with chronic moderate to severe primary MR were prospectively enrolled from 11 Asian tertiary hospitals (n = 850; mean age 56.

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Article Synopsis
  • Arginine vasopressin (AVP) is produced in the paraventricular (PVN) and supraoptic nuclei (SON) of the brain, with increased production in response to conditions like hypovolemia.
  • The study focuses on how hypovolemia and hyperosmolality affect AVP dynamics in the magnocellular and parvocellular divisions of the PVN, using genetically modified rats that express AVP-enhanced green fluorescent protein (eGFP).
  • Findings show that hypovolemia significantly upregulates AVP and corticotrophin-releasing factor (CRF) synthesis in the pPVN, subsequently activating the hypothalamic-pituitary-adrenal (HPA
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Background: An implantable cardioverter defibrillator (ICD) is the most reliable therapeutic device for preventing sudden cardiac death in patients with sustained ventricular tachycardia (VT). Regarding its effectiveness, targeted VT is defined based on the tachyarrhythmia cycle length. However, variations in RR interval variability of VTs may occur.

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Background: Right ventricular branch compromise (RVBC) following percutaneous coronary intervention (PCI) in patients with acute inferior myocardial infarction (AIMI) is associated with short-term adverse clinical outcomes. Chronic kidney disease (CKD) is also known to be a major risk factor after PCI in AIMI. However, little is known about the impact of RVBC and CKD on long-term prognosis.

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A 46-year-old man complained of chest pain at rest for the past three months. His symptoms gradually exacerbated and were suspected of being due to unstable angina. A coronary angiogram revealed focal tight stenosis at the proximal left anterior descending coronary artery with gross spastic coronary findings.

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Background: The aortic valve area index (AVAI) in aortic stenosis (AS) is measured by echocardiography with a continuity equation using the stroke volume index by Doppler (SVI) or biplane Simpson (SVI) method. AVAIand AVAIoften show discrepancy due to differences between SVIand SVI. The degree of discrepancy and utility of combined AVAIs have not been investigated in a large population of AS patients, and the characteristics of subjects with larger discrepancies are unknown.

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The mechanism of systolic annular expansion in mitral valve prolapse (MVP) is not clarified. Since annular expansion is systolic outward shift of MV leaflet/chorda tissue complex at superior and outer ends, annular expansion could be related to inward (superior) shift of the complex at another inferior and inner end of the papillary muscle (PM) tip and/or systolic lengthening of the tissue complex, especially MV leaflets.MV annulus systolic expansion, PMs' systolic superior shift, and MV leaflets' systolic lengthening were evaluated by echocardiography with a speckle tracking analysis in 25 normal subjects, 25 subjects with holo-systolic MVP and 20 subjects with late-systolic MVP.

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Mixed venous oxygen (O) saturation ([Formula: see text]) is an important measure for evaluating the sufficiency of cardiac output (CO) relative to whole body O consumption (V̇o), while clinical use is limited to the required invasive catheterization. According to Fick's equation, V̇o (mL/min) = CO (L/min) × Hb (g/dL) × 1.36 (mL/g) × ([Formula: see text] - [Formula: see text])/10 (Hb = hemoglobin concentration, [Formula: see text] = arterial blood O saturation).

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We generated a transgenic rat line that expresses oxytocin (OXT)-monomeric red fluorescent protein 1 (mRFP1) fusion gene to visualize the dynamics of OXT. In this transgenic rat line, hypothalamic OXT can be assessed under diverse physiological and pathophysiological conditions by semiquantitative fluorometry of mRFP1 fluorescence intensity as a surrogate marker for endogenous OXT. Using this transgenic rat line, we identified the changes in hypothalamic OXT synthesis under various physiological conditions.

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We report a case of a 77-year-old male who had been diagnosed with normal-flow high-pressure gradient severe aortic stenosis (AS) two years previously. In accordance with his wishes, it was decided not to perform surgery. He visited our hospital with anorexia and weight loss and was diagnosed with gastric cancer.

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Article Synopsis
  • The study investigated how insufficient elongation of the mitral valve complex (MVC) affects the shape and elongation of the left ventricle (LV) in patients with dilated cardiomyopathy (DCM) and aortic regurgitation (AR).
  • Using 3D echocardiography, researchers measured various tissue elongation ratios in patients and controls, finding that LV sphericity was reduced in DCM and AR cases, particularly regarding the LV-base-longitudinal tissue length.
  • The analysis indicated that reduced longitudinal elongation in the LV base is linked to changes in the MVC's longitudinal tissue, suggesting these structural alterations contribute to spherical remodeling in the heart.
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An 82-year-old woman received pacemaker implantation for sick sinus syndrome. Two days after the implantation, electrocardiography showed 2:1 atrial pacing failure, followed by a bradycardia-dependent increase in the atrial pacing threshold during a pacemaker examination. However, transient 1:1 atrial pacing capture recovered by adenosine triphosphate (ATP) administration, which was performed to evaluate the bradycardia-dependent pacing failure mechanism.

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Background: Third-generation drug-eluting-stents (3rd DES) may improve coronary arterial healing and reduce neoatherosclerosis formation. We evaluated post-stent findings and subsequent vascular healing of 3rd DES by comparing to second-generation drug-eluting-stents (2nd DES) at intermediate-term follow-up using optical coherence tomography (OCT).

Method: We evaluated 170 patients with 170 lesions who underwent DES implantation (2nd DES, n = 98; 3rd DES, n = 72) and OCT-guided follow-up examination.

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• Modest LV wall thickening is a common phenomenon after reperfusion therapy. • Wall thickening may be due to myocardial interstitial edema and/or hemorrhage. • Marked left ventricular wall thickening can reduce SV.

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Both brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are established biomarkers that are necessary in the diagnosis and management of heart failure (HF). However, it is difficult to infer BNP concentration from NT-proBNP concentration for a clinician who is familiar with BNP. We investigated whether estimated BNP concentration from NT-proBNP has an equivalent prognostic strength compared with the actual BNP concentration in the prediction of future outcomes.

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A 59-year-old female was brought to our emergency room with severe chest pain. Based on the electrocardiogram (ECG) and echocardiography, an acute coronary syndrome (ACS) was suspected. Her initial ECG showed ST elevation in the inferior leads (II, III, and aVF), which had progressed to involve the anterior leads (V2-V4) by the time she was shifted to the catheterization room.

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Article Synopsis
  • The study investigates the relevance of pressure recovery (PR) adjustment in resolving discrepancies between Doppler echocardiography and direct catheterization pressure measurements in patients with severe aortic stenosis (AS).
  • Data from 697 patients, primarily with severe AS, finds that PR adjustment significantly reclassifies a portion of patients from severe to moderate AS, impacting clinical outcomes.
  • Results indicate that patients reclassified after PR adjustment experience better clinical event-free survival rates and that this adjustment aids in predicting important outcomes like aortic valve replacement.
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