Publications by authors named "Takeshi Harita"

A 51-year-old woman presented with recurring palpitations. Electrocardiography revealed narrow QRS tachycardia with short RP configuration. Computed tomography showed coronary sinus (CS) ostial atresia along with a small persistent left superior vena cava (PLSVC).

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Background: Catheter ablation (CA) for atrial fibrillation (AF) is widely performed. However, the indication for CA in patients with asymptomatic persistent AF is still controversial.

Methods: Among 259 consecutive patients who were hospitalized for initial CA of AF, a total of 45 patients who had asymptomatic persistent AF were retrospectively analyzed.

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Aortic stenosis (AS), a late complication of thoracic radiation therapy for chest lesions, is often coincident with porcelain aorta or hostile thorax. We herein report a 59-year-old man with a history of mediastinal Hodgkin lymphoma treated with radiation therapy but later presenting with heart failure caused by severe AS. Severe calcification in the mediastinum and around the ascending aorta made it difficult to perform surgical aortic valve replacement.

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Background: Long QT syndrome type 3 (LQT3) is caused by gain-of-function mutations in the gene, which encodes the α subunit of the cardiac voltage-gated sodium channel. LQT3 patients present bradycardia and lethal arrhythmias during rest or sleep. Further, the efficacy of β-blockers, the drug used for their treatment, is uncertain.

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Article Synopsis
  • Chronic atrial fibrillation (AF) can lead to tricuspid regurgitation (TR), which is potentially influenced by right ventricular (RV) function; however, the specific relationship is not fully understood.
  • A study of 175 patients with chronic AF (averaging 78 years old) found that 35% exhibited significant TR, with these patients typically older and having longer AF durations along with enlarged right-side heart measurements.
  • Analysis of echocardiographic data revealed that prior to significant TR, patients showed larger RV dimensions, decreased RV strain, and less change in tricuspid annular diameter, suggesting that RV dysfunction might play a role in the later development of TR in chronic AF cases.
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The changes in cardiac function that occur after pericardiocentesis are unclear. An understanding of the effect of pericardiocentesis on right ventricular (RV) and left ventricular (LV) function is clinically important. This study was performed to assess RV and LV function with echocardiography before and after pericardiocentesis.

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A 37-year-old man presented with heart failure caused by severe aortic regurgitation (AR). He had a history of being involved in a traffic accident 3 months earlier. Imaging tests at admission detected no abnormalities in the aortic valve or aortic wall; however, the left coronary cusp prolapsed slightly on transthoracic echocardiography.

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The management of idiopathic dilated cardiomyopathy (DCM) is well established. However, a subset of patients do not have recovery from or have recurrences of left ventricular (LV) dysfunction despite receiving optimal medical therapy. There are limited long-term follow-up data about LV function and the predictive value of iodine-123-metaiodobenzylguanidine (I-MIBG) scintigraphy, especially among the Japanese population.

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Article Synopsis
  • - The study focuses on Long QT syndrome type 1 (LQT1) caused by a specific mutation in the KCNQ1 gene, which affects cardiac potassium channels, and investigates how this mutation leads to abnormal splicing in heart cells derived from a patient's stem cells.
  • - Researchers created patient-specific heart cells (hiPSC-CMs) to analyze the mutations, discovering seven complex RNA variants. They performed electrophysiology tests which showed that the mutated cells had altered responses to certain drugs, leading to longer action potential durations compared to control cells.
  • - The findings reveal that the mutation in KCNQ1 not only affects RNA splicing but also influences the electrical activity of heart cells, highlighting the potential for targeted therapies that
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Background: Mutations in (), which encodes lamin A and C, typically cause age-dependent cardiac phenotypes, including dilated cardiomyopathy, cardiac conduction disturbance, atrial fibrillation, and malignant ventricular arrhythmias. Although the type of mutations have been reported to be associated with susceptibility to malignant ventricular arrhythmias, the gene-based risk stratification for cardiac complications remains unexplored.

Methods And Results: The multicenter cohort included 77 mutation carriers from 45 families; cardiac disorders were retrospectively analyzed.

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Background: TheSCN5Agene encodes the α subunit of the cardiac voltage-gated sodium channel, Na1.5. The missense mutation, D1275N, has been associated with a range of unusual phenotypes associated with reduced Na1.

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Calmodulin is a ubiquitous Ca2+ sensor molecule encoded by three distinct calmodulin genes, CALM1-3. Recently, mutations in CALM1-3 have been reported to be associated with severe early-onset long-QT syndrome (LQTS). However, the underlying mechanism through which heterozygous calmodulin mutations lead to severe LQTS remains unknown, particularly in human cardiomyocytes.

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Introduction: Human induced pluripotent stem cells (hiPSCs) offer a unique opportunity for disease modeling. However, it is not invariably successful to recapitulate the disease phenotype because of the immaturity of hiPSC-derived cardiomyocytes (hiPSC-CMs). The purpose of this study was to establish and analyze iPSC-based model of catecholaminergic polymorphic ventricular tachycardia (CPVT), which is characterized by adrenergically mediated lethal arrhythmias, more precisely using electrical pacing that could promote the development of new pharmacotherapies.

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Background: Long-QT syndrome (LQTS) is an inherited arrhythmia characterized by prolonged ventricular repolarization and malignant tachyarrhythmias. LQT1, LQT2, and LQT3 are caused by mutations in KCNQ1 (LQT1), KCNH2 (LQT2), and SCN5A (LQT3), which account for approximately 90% of genotyped LQTS patients. Most cardiac events in LQT1 patients occur during exercise, whereas patients with LQT3 tend to have arrhythmic events during rest or asleep.

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Background: The purpose of this study was to evaluate the long-term safety of the Igaki-Tamai stent, the first-in-human fully biodegradable coronary stent made of poly-l-lactic acid.

Methods And Results: Between September 1998 and April 2000, 50 patients with 63 lesions were treated electively with 84 Igaki-Tamai stents. Overall clinical follow-up (>10 years) of major adverse cardiac events and rates of scaffold thrombosis was analyzed together with the results of angiography and intravascular ultrasound.

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