Publications by authors named "Takahide Kadosaka"
Background: Battery longevity in high-voltage devices (HVDs), specifically implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy-defibrillators (CRT-Ds), is critical for reducing the frequency of generator replacements, minimizing procedural risks, and enhancing patient outcomes. Despite technological advancements, significant variability in battery performance remains among the major manufacturers. This study aimed to evaluate the battery longevity among ICDs and CRT-Ds from the major manufacturers implanted at a single institution and identify the factors influencing battery depletion.
View Article and Find Full Text PDFBackground: Ventricular arrhythmias (VAs) in chronic ischemic heart failure (HF) are associated with high mortality and often refractory to beta-blocker treatment, highlighting the need for alternative therapeutic targets.
Objective: This study investigates the role of neuropeptide Y (NPY), a neurotransmitter released during sympathoexcitation, in the pathogenesis of VAs associated with ischemic chronic HF following myocardial infarction (MI).
Methods: Using a mouse model of ischemic chronic HF after coronary ligation, we employed biochemical, electrophysiological, and calcium ion (Ca) imaging analyses to investigate the proarrhythmic mechanisms of NPY.
Background: Low-voltage areas in the left atrium predict atrial fibrillation recurrence after catheter ablation and are associated with adverse outcomes like death, heart failure, and stroke. Detecting low-voltage areas (LVAs) typically requires invasive procedures, highlighting the need for a simple, minimally invasive marker. Vasoactive intestinal peptide (VIP), a neuropeptide released during parasympathetic stimulation, affects electrophysiological remodeling in atrial fibrillation.
View Article and Find Full Text PDFNormalization of increasing shocking coil impedance with full output synchronized shock.
J Cardiovasc Electrophysiol
November 2024
Article Synopsis
- - Impedance is an important factor for cardiovascular implantable electronic devices (CIEDs), and low voltage sub-threshold measurement (LVSM) is commonly used to measure it, although it can sometimes be inaccurate due to tissue changes.
- - A case study showed that elevated LVSM shock impedance (LVSM-SI) occurred 8 years after lead implantation, likely due to tissue encapsulation around the lead, but normal values were found after administering a high voltage shock.
- - The study suggests that performing a full-output synchronized shock test can help evaluate high voltage shock impedance (HVSI) when LVSM-SI readings are abnormal, potentially restoring normal LVSM-SI values.
Article Synopsis
- Epicardial adipose tissue (EAT) influences atrial fibrillation (AF) but its role in postoperative AF (POAF) is not well understood; this study examines how EAT relates to POAF in cardiovascular surgery patients.
- Out of 53 patients, 34% experienced POAF within a week after surgery, but no major differences in EAT profiles were found between patients with and without POAF.
- Key findings include that higher levels of tumor necrosis factor-alpha (TNF-α) mRNA are linked to increased POAF risk, while larger adipocyte sizes correlate inversely with POAF onset; mitochondrial OXPHOS was unrelated to POAF but associated with secretory activities and adipocyte
Optogenetic termination of atrial tachyarrhythmias by brief pulsed light stimulation.
J Mol Cell Cardiol
May 2023
Article Synopsis
- Scientists are studying a new way to treat a heart problem called atrial fibrillation (AF) using special light instead of painful electric shocks.
- This method uses light to change how cells in the heart behave, which could potentially stop the heart from beating too fast.
- The study found that shining light on the heart cells helped them stay in a normal rhythm, showing that this technique might be a promising and painless treatment for heart issues in the future.
Article Synopsis
- Recent studies indicate that SGLT2 inhibitors like empagliflozin may lower the risk of atrial fibrillation in diabetes patients by reducing oxidative stress linked to mitochondrial-ROS generation.
- In a rat model of type-2 diabetes, treating with empagliflozin improved heart function by reducing atrial tachyarrhythmia, fibrosis, and mitochondrial dysfunction that are exacerbated in diabetes.
- The findings highlight empagliflozin's potential to enhance mitochondrial health and cardiac function, suggesting it could serve as a beneficial treatment for diabetes-related heart issues.
Fragmented QRS (fQRS) on a 12-lead electrocardiogram is a known marker of fatal arrhythmias or cardiac adverse events in ischemic and non-ischemic cardiomyopathy patients. Nonetheless, the association between fQRS and clinical outcomes in patients with cardiac sarcoidosis (CS) remains unclear. Herein, we investigated whether fQRS is associated with long-term clinical outcomes in CS patients.
View Article and Find Full Text PDFEmpagliflozin attenuates arrhythmogenesis in diabetic cardiomyopathy by normalizing intracellular Ca handling in ventricular cardiomyocytes.
Am J Physiol Heart Circ Physiol
March 2023
Article Synopsis
- Diabetic cardiomyopathy increases the risk of fatal ventricular arrhythmias, and the effects of the SGLT2 inhibitor empagliflozin (EMPA) on heart protection have not been extensively studied.
- In experiments using diabetic and control mice, EMPA treatment preserved heart function, reduced premature ventricular complexes during arrhythmia induction, and normalized calcium handling in diabetic cardiomyocytes.
- The improvements seen with EMPA were linked to decreased glucose uptake and reduced autophosphorylation of specific proteins, suggesting that managing glucose levels may help mitigate arrhythmia risks in diabetic heart conditions.
Pharmacological nNOS inhibition modified small-conductance Ca-activated K channel without altering Ca dynamics.
Am J Physiol Heart Circ Physiol
November 2022
Article Synopsis
- Atrial fibrillation (AF) leads to electrical changes in the heart, with the small-conductance Ca-activated K (SK) channel playing a crucial role, though its activation mechanism is still not well understood.
- In a study using rat hearts, researchers inhibited neuronal nitric oxide synthase (nNOS) to explore its effects on atrial tachyarrhythmia (ATA) and used specific blockers to investigate the SK channel's influence on action potential duration (APD) and other parameters.
- The findings revealed that inhibiting nNOS increased ATA inducibility and shortened APD, while the SK channel blocker apamin counteracted these effects without changing calcium transients, suggesting that posttranslational modifications of SK channels may
Article Synopsis
- - An increase in diastolic calcium levels in heart cells is linked to heart failure and can lead to dangerous heart rhythms; the study explores if mitochondria can help manage this calcium increase.
- - Researchers used a mouse model of heart failure and tested the effects of kaempferol on calcium dynamics and heart function, observing improved outcomes in calcium regulation and reduced arrhythmias.
- - Findings suggest that mitochondria can partially compensate for high calcium levels in heart failure, offering new avenues for treatments addressing heart failure-related arrhythmias.
Background: Electrical storms (ESs) in patients with structural heart disease (SHD) have been reported to be associated with a poor prognosis. However, the detailed cause of death and influence of implantable cardioverter defibrillator (ICD) therapy in ES patients have not been fully investigated. Therefore, we sought to explore the detailed clinical course after an ES and the impact of the ICD therapy in patients with SHDs.
View Article and Find Full Text PDFArticle Synopsis
- Doctors can do a special heart surgery called epicardial catheter ablation for patients who have had heart surgery before.
- They used a method called thoracotomy to reach a specific part of the heart to fix a problem called ventricular tachycardia (VT) in a patient with a certain heart condition.
- By using 3D images and previous tests, they could safely do this surgery with less invasion and successfully stop the VT.
Acute myocardial infarction (AMI) caused by severe stenosis of left main coronary artery (LMCA) presenting with cardiogenic shock and pulmonary edema during noncardiac surgery is uncommon, but a catastrophic event. A 77-year-old male with cholangiocarcinoma underwent hepatectomy. During the surgery, he presented with cardiogenic shock, which did not respond to infusion administration or vasopressor.
View Article and Find Full Text PDFWe report a case of cardiac lipoma with intramyocardial invasion complicated by visceral inversion, which, to the best of our knowledge, has not been reported before. Multimodality imaging played an important role in differential diagnosis and determination of the management strategy. ().
View Article and Find Full Text PDFPurpose: Although direct oral anticoagulants are effective and safe in preventing stroke in atrial fibrillation (AF) patients with low body weight, data remain limited in AF patients with extremely low body weight (<50 kg). We aimed to investigate the association of this body weight category with clinical outcomes in elderly AF patients receiving apixaban.
Methods: The J-ELD AF Registry is a large-scale, multicenter prospective observational study of Japanese non-valvular AF patients aged ≥ 75 years taking on-label doses of apixaban.
Anti-mitochondrial antibody (AMA)-positive myositis is an atypical inflammatory myopathy characterized by chronic progressive respiratory muscle weakness, muscular atrophy, and cardiac involvement. Arrhythmias, cardiomyopathy, and myocarditis have been reported as cardiac manifestations. Herein, we present the first report of a patient diagnosed with having AMA-positive myositis with cardiac involvement mimicking cardiac sarcoidosis.
View Article and Find Full Text PDFArticle Synopsis
- Hypertrophic cardiomyopathy (HCM) with an apical aneurysm (AA) is uncommon but can trigger severe ventricular tachycardias (VTs), often linked to a specific area in the heart called the central isthmus.
- The report discusses a unique case where a patient with HCM and AA successfully underwent an epicardial ablation procedure to treat refractory VT stemming from the true apex of the aneurysm.
- During the ablation, mid-diastolic electrical signals were detected in the surrounding scar tissue, and applying radiofrequency energy effectively stopped the VT from occurring again.
Article Synopsis
- - Epirubicin-based chemotherapy, though infrequently, can lead to heart failure, while bevacizumab is now commonly used for recurrent breast cancer treatment despite its rare risk of heart-related issues.
- - A case study highlights a breast cancer patient who experienced reversible cardiac dysfunction linked to both bevacizumab and epirubicin, resulting in blood clots in the heart's left atrium and ventricle.
- - This situation emphasizes the need for personalized medical planning for patients undergoing anti-cancer treatments to manage potential cardiovascular complications effectively.
A 76-year-old woman with sarcoidosis who had an implantable pacemaker for complete atrioventricular block was admitted with syncope. Electrocardiogram revealed ventricular pacing failure, and a marked rise in the ventricular pacing threshold. F-Fluorodeoxyglucose positron emission tomography (FDG-PET) indicated increased uptake of FDG in the ventricular septum.
View Article and Find Full Text PDFBackground: The pre-ejection period (PEP) and left ventricular ejection time (LVET) are easily measured by impedance cardiography (ICG). We hypothesized that the PEP/LVET measured by ICG would correlate with that measured by echocardiography, and that PEP/LVET measured by ICG would be useful for cardiac resynchronization therapy (CRT) optimization.
Methods: Newly CRT implanted patients were optimized by echocardiography.