Publications by authors named "Takafumi Oka"

DSG2, encoding desmoglein-2, is one of the causative genes of arrhythmogenic cardiomyopathy. We previously identified a homozygous DSG2 p.Arg119Ter stop-gain variant in a patient with juvenile-onset cardiomyopathy and advanced biventricular heart failure.

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Unlabelled: New cardiac implantable electronic devices (CIEDs), such as leadless pacemakers and subcutaneous implantable cardioverter defibrillators (S-ICDs), are being used in patients with adult congenital heart disease. The selection of CIEDs often requires careful consideration due to technical challenges posed by a unique heart structure. A 27-year-old man following a surgical tetralogy of Fallot (TOF) repair developed non-sustained ventricular tachycardia, sick sinus syndrome, and complete atrioventricular block.

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The pacing maneuvers for supraventricular tachycardia with cycle length alternans are sometimes difficult, especially when diagnostic ventricular pacing does not conduct to the atrium. Even in such a situation, critical diagnostic findings can be obtained by spontaneous premature ventricular contraction.

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Article Synopsis
  • Atrial cardiomyopathy (AtCM) is gaining attention for its association with serious cardiovascular issues like atrial tachyarrhythmia and strokes, but little is known about its long-term effects since it's a relatively new concept.
  • A case study of a 78-year-old man revealed he had end-stage AtCM, diagnosed after decades of battling atrial fibrillation and several related complications, including cardiogenic embolism and ineffective heart ablation treatments.
  • Despite ongoing treatment, the patient faced worsening symptoms and complications, emphasizing the importance of monitoring and managing the progression of AtCM.
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  • The study investigates how changes in pacing cycle length (PCL) affect the electrical properties of the left atrium during atrial fibrillation ablation, using a high-resolution mapping system.
  • Atrial mapping was conducted on 48 patients, revealing that a shorter PCL (300 ms) increased the low-voltage area (LVA) and prolonged activation time, suggesting significant shifts in electrical activity.
  • The findings highlight the importance of considering PCL-dependent changes when evaluating LVA and slow conduction areas as potential substrates for atrial fibrillation, indicating their assessments may not be fully valid without this context.
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  • In a study analyzing treatments for persistent atrial fibrillation (AF), researchers compared extensive ablation techniques (including pulmonary vein isolation and additional methods) with just pulmonary vein isolation (PVI) in young (<65 years) and elderly (≥65 years) patients.
  • They found that while both methods were equally effective in younger patients, extensive ablation significantly reduced AF recurrence in elderly patients.
  • The study concluded that extensive ablation is a more effective treatment for elderly patients with persistent AF, without any serious procedural complications reported.
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An extremely high generator impedance in the blood pool can be observed in a patient with severe polycythemia. However, ablation can be performed safely as long as the generator impedance during contact with the myocardial tissue is within acceptable limits.

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Article Synopsis
  • Extensive ablation, when added to pulmonary vein isolation (PVI), shows varied effectiveness in patients with persistent atrial fibrillation (AF), especially in those with mitral regurgitation (MR).
  • A post-hoc analysis from the EARNEST-PVI trial revealed that while PVI alone and PVI-plus had similar recurrence rates in non-MR patients, PVI-plus significantly reduced AF recurrence in MR patients.
  • The study suggests that customizing ablation techniques based on MR presence can improve patient outcomes in AF treatment.
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An 87-year-old man developed delayed cardiac tamponade 55 min after leadless pacemaker implantation and recurrent pericardial effusion 20 days later. Electrocardiogram-gated enhanced cardiac computed tomography revealed that the leadless pacemaker tines on the lateral side had penetrated the right ventricular free wall. He underwent off-pump hemostatic surgery.

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Background: It has not been fully elucidated which patients with persistent atrial fibrillation (PerAF) should undergo substrate ablation plus pulmonary vein isolation (PVI). This study aimed to identify PerAF patients who required substrate ablation using intraprocedural assessment of the baseline rhythm and the origin of atrial fibrillation (AF) triggers.

Methods and results: This was a post hoc subanalysis using extended data of the EARNEST-PVI trial, a prospective multicenter randomized trial comparing PVI-alone and PVI-plus (i.

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Aims: Blood stasis is crucial in developing left atrial (LA) thrombi. LA appendage peak flow velocity (LAAFV) is a quantitative parameter for estimating thromboembolic risk. However, its impact on LA thrombus resolution and clinical outcomes remains unclear.

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Background: The clinical significance of left atrial local electrogram fractionation after restoration of sinus rhythm in patients with atrial fibrillation (AF) has not been elucidated.

Methods: We evaluated ultrahigh-resolution maps of the left atrium (LA) during RA pacing acquired after pulmonary vein isolation in 40 patients with AF. The association between low-voltage area (LVA, <0.

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Introduction: Persistent left superior vena cava (PLSVC) is one of the major sources of triggers and drivers of atrial fibrillation (AF). There has been no established PLSVC ablation procedure to eliminate the arrhythmogenicity along the entire length of PLSVC.

Methods And Results: A 70-year-old woman with a history of two previous catheter ablations for AF, mitral valvuloplasty, and an unroofed coronary sinus-type atrial septal defect closure underwent the redo AF ablations.

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Article Synopsis
  • The study investigates how the duration of atrial fibrillation (AF) affects the success of catheter ablation in patients with long-standing AF (LsAF).
  • It found that patients with LsAF lasting 1-2.4 years have similar outcomes to those with persistent AF (PerAF), but those with LsAF over 2.4 years face a higher risk of arrhythmia recurrence.
  • Additionally, patients with LsAF over 2.4 years might benefit more from a combined ablation strategy (PVI-plus) than from a standard approach (PVI-alone).
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  • A study aimed to find patients with persistent atrial fibrillation (AF) who would benefit from extensive catheter ablation, using a machine learning method called uplift modeling.
  • The research identified the best model as adaptive boosting, which indicated that an uplift score of 0.0124 could effectively determine who would benefit from the more extensive procedure.
  • Results showed that patients with an uplift score of 0.0124 or higher had a significantly lower recurrence of AF with the extensive ablation (PVI-plus) compared to those receiving only the standard procedure (PVI-alone).
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Unlabelled: A 66-year-old female underwent persistent atrial fibrillation ablation. After pulmonary vein isolation and homogenization of low-voltage areas (LVAs), atrial tachycardia (AT) was not induced at the first session; however, it recurred one year after the procedure. During the second session, the extensive LVAs were distributed in the same area of the left atrial anterior wall and expanded possibly due to the previous LVA homogenization.

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  • There has been observed electromagnetic interference (EMI) between implantable left ventricular assist devices and cardiac implantable electronic devices.
  • A new case highlighted EMI between a percutaneous ventricular assist device and an implantable cardioverter-defibrillator, confirmed through ex vivo simulation testing.
  • The level of EMI might vary based on the distance between the two types of devices.
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Background An optimal strategy for left atrial ablation in addition to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) has not been determined. Methods and Results We conducted an extended follow-up of the multicenter randomized controlled EARNEST-PVI (Efficacy of Pulmonary Vein Isolation Alone in Patients With Persistent Atrial Fibrillation) trial, which compared 12-month rhythm outcomes in patients with persistent AF between patients randomized to a PVI-alone strategy (n=248) or PVI-plus strategy (n=248; PVI followed by left atrial additional ablation, including linear ablation or ablation targeting areas with complex fractionated electrograms). The present study extended the follow-up period to 3 years after enrollment.

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Heart failure is a leading cause of mortality in developed countries. Cell death is a key player in the development of heart failure. Calcium-independent phospholipase Aβ (iPLAβ) produces lipid mediators by catalyzing lipids and induces nuclear shrinkage in caspase-independent cell death.

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Biatrial tachycardia via Bachmann's bundle, interatrial septum, and left atrial anterior wall can be treated by left atrial anterolateral linear ablation without left atrial appendage isolation, even under mitral isthmus block.

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• Intra-isthmus reentry is a variant of cavotricuspid isthmus-dependent atrial flutter. • Intra-isthmus reentry circuit can involve the rotational activation around the coronary sinus ostium. • Ultrahigh-resolution mapping can help delineate the complete intra-isthmus reentry circuit.

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Article Synopsis
  • - Nifekalant effectively reduced intra-superior vena cava fibrillation.
  • - This type of fibrillation complicated the assessment of superior vena cava isolation.
  • - The success of Nifekalant in this context highlights its potential in managing specific cardiac rhythms during medical evaluations.
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