14 results on '"Takahisa Koi"'
Search Results
2. Urinary isoxanthopterin as a novel predictor following catheter ablation for atrial fibrillation
- Author
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Takahisa Koi, Naoya Kataoka, Keisuke Uchida, Teruhiko Imamura, and Koichiro Kinugawa
- Subjects
atrial fibrillation ,atrial tachyarrhythmias ,oxidative stress ,urinary isoxanthopterin ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Abstract Background Oxidative stress is associated with atrial fibrillation recurrence following catheter ablation. Urinary isoxanthopterin (U‐IXP) is one of the noninvasive markers which reflect the reactive oxygen species; however, its ability to predict atrial tachyarrhythmias (ATAs) occurrence following catheter ablation remains uncertain. Methods Among the patients who received scheduled catheter ablation for atrial fibrillation, baseline U‐IXP levels were measured just before the procedure. The prognostic impact of baseline U‐IXP upon postprocedural ATAs occurrence was investigated. Results Among 107 patients (71 years old, 68% men), baseline U‐IXP level was 0.33 nmol/gCr on the median. During a mean of 603 days of follow‐up, 32 patients had ATAs. Baseline higher U‐IXP was independently associated with the occurrence of ATAs following catheter ablation with a hazard ratio of 4.69 (95% confidence interval: 1.82–12.37, p = .001) adjusted for the left atrial diameter, a persistent type, and hypertension which were potential confounders, with a cutoff of 0.46 nmol/gCr, which stratified cumulative incidence of ATAs occurrence ( p
- Published
- 2023
- Full Text
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3. Adverse Events Requiring Hospitalization Following Catheter Ablation for Atrial Fibrillation in Heart Failure with versus without Systolic Dysfunction
- Author
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Naoya Kataoka, Teruhiko Imamura, Takahisa Koi, Keisuke Uchida, and Koichiro Kinugawa
- Subjects
heart failure ,atrial fibrillation ,catheter ablation ,major bleeding ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background: The safety and efficacy of atrial fibrillation (AF) ablation in individuals with heart failure (HF) with preserved ejection fraction (EF), particularly concerning the occurrence of post-procedural adverse events necessitating hospitalization, including anticoagulant-associated major bleeding, still lack conclusive determination. Methods: Data from patients with HF and AF who underwent catheter ablation for AF between 2019 and 2022 at our institution were retrospectively reviewed. All participants were divided into an EF < 50% group or an EF ≥ 50% group according to their baseline left ventricular EF. The composite incidence of the clinical events following catheter ablation was compared between the two groups: (1) all-cause death, (2) HF hospitalization, (3) stroke or systemic embolism, and (4) major bleeding. Results: A total of 122 patients (75 years old, 68 male) were included. Of them, 62 (50.8%) patients had an EF ≥ 50%. EF ≥ 50% was an independent predictor of the composite endpoint (adjusted odds ratio 6.07, 95% confidence interval 1.37–26.99, p = 0.018). The incidences of each adverse event were not significantly different between the two groups, except for a higher incidence of major bleeding in the EF ≥ 50% group (12.7% vs. 0%, p = 0.026). Conclusions: Among patients with HF coupled with AF, the incidence of adverse events following AF ablation proved notably elevated in patients with EF ≥ 50% in contrast to their counterparts with EF < 50%. This disparity primarily stems from a heightened occurrence of major bleeding within the EF ≥ 50% cohort. The strategy to reduce adverse events, especially in patients with EF ≥ 50%, remains the next concern.
- Published
- 2024
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4. Impact of S-Wave Amplitude in Right Precordial Leads on Improvement in Mitral Regurgitation following Cardiac Resynchronization Therapy
- Author
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Naoya Kataoka, Teruhiko Imamura, Takahisa Koi, Shuhei Tanaka, Nobuyuki Fukuda, Hiroshi Ueno, and Koichiro Kinugawa
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heart failure ,cardiac resynchronization therapy ,QRS amplitude ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background: The therapeutic strategy for mitral regurgitation (MR) in patients with advanced heart failure and wide QRS complex who are indicated for both intervention to MR and cardiac resynchronization therapy (CRT), remains unclear. Objective: We aimed to determine electrocardiogram parameters that associate with MR reduction following CRT implantation. Methods: Among the patients with advanced heart failure and functional MR who intended to receive CRT implantation, baseline QRS morphology, electrical axis, PR interval, QRS duration, and averaged S-wave in right precordial leads (V1 to V3) in surface electrocardiogram were measured. The impact of these parameters on MR reduction following CRT implantation, which was defined as a reduction in MR ≥1 grade six months later, was investigated. Results: In 35 patients (median 71 years old, 18 men), 17 (49%) achieved an MR reduction following CRT implantation. Among baseline characteristics, only the higher S-wave amplitude in right precordial leads was an independent predictor of MR reduction (odds ratio 14.00, 95% confidence interval 1.65–119.00, p = 0.016) with a cutoff of 1.3 mV calculated through the area under the curve. The cutoff significantly stratified the cumulative incidences of heart failure re-admission and percutaneous mitral valve repair following CRT implantation (p = 0.032 and p = 0.011, respectively). Conclusions: In patients with advanced heart failure and functional MR, the baseline higher amplitude of S-wave in the right precordial leads might be a good indicator of MR improvement following CRT.
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- 2022
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5. A Simple Predictive Marker in Cardiac Resynchronization Therapy Recipients: Prominent S-Wave in Right Precordial Leads
- Author
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Naoya Kataoka, Teruhiko Imamura, Takahisa Koi, Keisuke Uchida, and Koichiro Kinugawa
- Subjects
heart failure ,cardiac resynchronization therapy ,QRS amplitude ,Medicine (General) ,R5-920 - Abstract
Background and objectives: Current guidelines criteria do not satisfactorily discriminate responders to cardiac resynchronization therapy (CRT). QRS amplitude is an established index to recognize the severity of myocardial disturbance and might be a key to optimal patient selection for CRT. Materials and Methods: (1) Initial R-wave amplitude, (2) S-wave amplitude, and (3) a summation of maximal R- or R′-wave amplitude and S-wave amplitude were measured at baseline. These parameters were averaged according to right (V1 to V3) or left (V4 to V6) precordial leads. The impact of these parameters on response to CRT, which was defined as a decrease in left ventricular end-systolic volume ≥15% at six-month follow-up, was investigated. Results: Among 47 patients (71 years old, 28 men) who received guideline-indicated CRT implantation, 25 (53%) achieved the definition of CRT responder. Among baseline electrocardiogram parameters, only the higher S-wave amplitude in right precordial leads was an independent predictor of CRT responders (odds ratio: 2.181, 95% confidence interval: 1.078–4.414, p = 0.030) at a cutoff of 1.44 mV. The cutoff was independently associated with cumulative incidence of heart failure readmission and appropriate electrical defibrillation following CRT implantation (p < 0.05, respectively). Conclusions: Prominent S-wave in right precordial leads might be a promising index to predict left ventricular reverse remodeling and greater clinical outcomes following CRT implantation.
- Published
- 2021
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- View/download PDF
6. The Large Right Heart Is Associated with the Prolongation of the Procedure Time of Leadless Pacemaker Implantation
- Author
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Naoya Kataoka, Teruhiko Imamura, Takahisa Koi, Hiroshi Ueno, and Koichiro Kinugawa
- Subjects
Micra ,procedure time ,right heart ,Medicine (General) ,R5-920 - Abstract
Background and objectives: Leadless pacemakers are less invasive but are as effective as conventional pacemakers and are increasingly implanted in elderly patients. However, the implantation procedure is sometimes challenging in patients with abnormal anatomy, particularly those with an enlarged right heart. We aimed to determine the right heart parameters that were associated with longer procedure times for leadless pacemaker implantation. Materials and Methods: Among 19 consecutive patients in whom Micra leadless pacemakers (Micra TPS, Medtronic, Minneapolis, MN) were implanted, the diameter and area of both the right atrium and right ventricle were measured by transthoracic echocardiography before the procedure. The right heart parameters that were associated with a procedure time > 60 min were investigated. Results: In the 19 patients (median 81 years old, 10 male) who underwent implantation of the Micra system, 6 (32%) required a procedure time > 60 min. Among the baseline right heart echocardiographic parameters, right atrial diameter and area were significantly associated with a procedure time > 60 min (odds ratio 11.3, 95% confidence interval 1.09–1.17, p = 0.042; and odds ratio 1.57, 95% confidence interval 1.05–2.34, p = 0.029, respectively) at a cutoff of 4.0 cm and 17.0 cm2, respectively. Conclusions: Patients with an enlarged right atrium may not be good candidates for leadless pacemakers given the longer procedure time, and conventional pacemakers should perhaps be recommended as an alternative.
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- 2021
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7. Drastic Cardiac Reverse Remodeling Following Catheter Ablation in Patients with Atrial Fibrillation and Heart Failure
- Author
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Takahisa Koi, Naoya Kataoka, Teruhiko Imamura, and Koichiro Kinugawa
- Subjects
hemodynamics ,reverse remodeling ,arrhythmia ,Medicine (General) ,R5-920 - Abstract
In the management of atrial fibrillation in patients with heart failure, rate control is recommended, whereas the implication of rhythm control remains controversial. We experienced a 65-year-old man who had compensated heart failure due to hypertensive heart disease and atrial fibrillation with well-controlled heart rate (
- Published
- 2021
- Full Text
- View/download PDF
8. Bail-out Ablation of Ventricular Tachycardia Electrical Storm in a Patient with a Durable Left Ventricular Assist Device
- Author
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Toshihide Izumida, Naoya Kataoka, Teruhiko Imamura, Keisuke Uchida, Takahisa Koi, Masaki Nakagaito, Makiko Nakamura, Yuki Komatsu, Akihiko Nogami, and Koichiro Kinugawa
- Subjects
Internal Medicine ,General Medicine - Abstract
The therapeutic strategy for sustained ventricular tachycardia (VT) during left ventricular assist device usage remains unclear. We encountered a patient with durable left ventricular assist device who presented sustained VT. Electrophysiological mapping was able to be established appropriately owing to the robust mechanical hemodynamics support despite inter-device interference. The three-dimensional activation map of clinically documented VT demonstrated that the propagation exited from the right ventricular apex through the critical isthmus located at the epicardium or interventricular septum, which was successfully treated by catheter ablation at the exit site. Further experiences like ours should be accumulated to establish a therapeutic strategy.
- Published
- 2022
9. Bail-out Ablation of Ventricular Tachycardia Electrical Storm in a Patient with a Durable Left Ventricular Assist Device.
- Author
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Toshihide Izumida, Naoya Kataoka, Teruhiko Imamura, Keisuke Uchida, Takahisa Koi, Masaki Nakagaito, Makiko Nakamura, Yuki Komatsu, Akihiko Nogami, and Koichiro Kinugawa
- Published
- 2023
- Full Text
- View/download PDF
10. A Simple Predictive Marker in Cardiac Resynchronization Therapy Recipients: Prominent S-Wave in Right Precordial Leads
- Author
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Keisuke Uchida, Koichiro Kinugawa, Takahisa Koi, Teruhiko Imamura, and Naoya Kataoka
- Subjects
Male ,Medicine (General) ,medicine.medical_specialty ,genetic structures ,Defibrillation ,medicine.medical_treatment ,Cardiac resynchronization therapy ,heart failure ,cardiac resynchronization therapy ,QRS amplitude ,Article ,QRS complex ,Electrocardiography ,R5-920 ,Internal medicine ,medicine ,Cutoff ,Humans ,Cumulative incidence ,cardiovascular diseases ,Aged ,Predictive marker ,Ventricular Remodeling ,business.industry ,General Medicine ,medicine.disease ,Confidence interval ,Treatment Outcome ,Heart failure ,Cardiology ,cardiovascular system ,business - Abstract
Background and objectives: Current guidelines criteria do not satisfactorily discriminate responders to cardiac resynchronization therapy (CRT). QRS amplitude is an established index to recognize the severity of myocardial disturbance and might be a key to optimal patient selection for CRT. Materials and Methods: (1) Initial R-wave amplitude, (2) S-wave amplitude, and (3) a summation of maximal R- or R′-wave amplitude and S-wave amplitude were measured at baseline. These parameters were averaged according to right (V1 to V3) or left (V4 to V6) precordial leads. The impact of these parameters on response to CRT, which was defined as a decrease in left ventricular end-systolic volume ≥15% at six-month follow-up, was investigated. Results: Among 47 patients (71 years old, 28 men) who received guideline-indicated CRT implantation, 25 (53%) achieved the definition of CRT responder. Among baseline electrocardiogram parameters, only the higher S-wave amplitude in right precordial leads was an independent predictor of CRT responders (odds ratio: 2.181, 95% confidence interval: 1.078–4.414, p = 0.030) at a cutoff of 1.44 mV. The cutoff was independently associated with cumulative incidence of heart failure readmission and appropriate electrical defibrillation following CRT implantation (p <, 0.05, respectively). Conclusions: Prominent S-wave in right precordial leads might be a promising index to predict left ventricular reverse remodeling and greater clinical outcomes following CRT implantation.
- Published
- 2021
- Full Text
- View/download PDF
11. The Large Right Heart Is Associated with the Prolongation of the Procedure Time of Leadless Pacemaker Implantation
- Author
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Teruhiko Imamura, Hiroshi Ueno, Naoya Kataoka, Koichiro Kinugawa, and Takahisa Koi
- Subjects
Male ,Medicine (General) ,Pacemaker, Artificial ,medicine.medical_specialty ,Heart Ventricles ,030204 cardiovascular system & hematology ,Right atrial ,Article ,Pacemaker implantation ,03 medical and health sciences ,R5-920 ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,In patient ,Heart Atria ,030212 general & internal medicine ,Device Removal ,right heart ,Aged ,Procedure time ,Aged, 80 and over ,procedure time ,business.industry ,General Medicine ,Odds ratio ,Confidence interval ,Micra ,Treatment Outcome ,medicine.anatomical_structure ,Ventricle ,Right heart ,Cardiology ,business - Abstract
Background and objectives: Leadless pacemakers are less invasive but are as effective as conventional pacemakers and are increasingly implanted in elderly patients. However, the implantation procedure is sometimes challenging in patients with abnormal anatomy, particularly those with an enlarged right heart. We aimed to determine the right heart parameters that were associated with longer procedure times for leadless pacemaker implantation. Materials and Methods: Among 19 consecutive patients in whom Micra leadless pacemakers (Micra TPS, Medtronic, Minneapolis, MN) were implanted, the diameter and area of both the right atrium and right ventricle were measured by transthoracic echocardiography before the procedure. The right heart parameters that were associated with a procedure time >, 60 min were investigated. Results: In the 19 patients (median 81 years old, 10 male) who underwent implantation of the Micra system, 6 (32%) required a procedure time >, 60 min. Among the baseline right heart echocardiographic parameters, right atrial diameter and area were significantly associated with a procedure time >, 60 min (odds ratio 11.3, 95% confidence interval 1.09–1.17, p = 0.042, and odds ratio 1.57, 95% confidence interval 1.05–2.34, p = 0.029, respectively) at a cutoff of 4.0 cm and 17.0 cm2, respectively. Conclusions: Patients with an enlarged right atrium may not be good candidates for leadless pacemakers given the longer procedure time, and conventional pacemakers should perhaps be recommended as an alternative.
- Published
- 2021
- Full Text
- View/download PDF
12. Drastic Cardiac Reverse Remodeling Following Catheter Ablation in Patients with Atrial Fibrillation and Heart Failure
- Author
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Koichiro Kinugawa, Teruhiko Imamura, Takahisa Koi, and Naoya Kataoka
- Subjects
medicine.medical_specialty ,Medicine (General) ,Ejection fraction ,business.industry ,medicine.medical_treatment ,Hemodynamics ,Management of atrial fibrillation ,Atrial fibrillation ,Catheter ablation ,Case Report ,General Medicine ,medicine.disease ,hemodynamics ,arrhythmia ,reverse remodeling ,Hypertensive heart disease ,R5-920 ,Internal medicine ,Heart failure ,Heart rate ,medicine ,Cardiology ,cardiovascular system ,business - Abstract
In the management of atrial fibrillation in patients with heart failure, rate control is recommended, whereas the implication of rhythm control remains controversial. We experienced a 65-year-old man who had compensated heart failure due to hypertensive heart disease and atrial fibrillation with well-controlled heart rate (
- Published
- 2021
13. Micra trans-catheter leadless pacemaker implantation in a patient with large right heart
- Author
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Takahisa Koi, Koichiro Kinugawa, Shuhei Tanaka, Hiroshi Ueno, Teruhiko Imamura, and Naoya Kataoka
- Subjects
Bradycardia ,medicine.medical_specialty ,Atrial standstill ,business.industry ,Atrial fibrillation ,Case Report ,Regurgitation (circulation) ,030204 cardiovascular system & hematology ,medicine.disease ,Pacemaker implantation ,03 medical and health sciences ,Catheter ,0302 clinical medicine ,Internal medicine ,Heart failure ,Right heart ,cardiovascular system ,Cardiology ,Medicine ,030212 general & internal medicine ,cardiovascular diseases ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business - Abstract
The use of leadless trans-catheter pacemakers is increasing particularly in the elderly population. However, its indication for those with anatomical anomaly remains unknown. We had a 75-year-old woman with atrial standstill and ventricular escape. Micra leadless pacemaker (Medtronic, Inc, Minneapolis, MN, USA) failed to be deployed due to too enlarged right atrium accompanied by atrial septal deficiency, followed by successful implantation of transvenous pacemaker lead by using SelectSecure lead (Medtronic) with a C315 delivery catheter that enhanced back-up force toward the ventricular septum against significant tricuspid regurgitation. The Micra is a promising system, but we should understand its limitations as well as alternative systems particularly for such an anatomical anatomy.
- Published
- 2021
14. Dose Reduction and Image Quality Optimization of Pediatric Chest Radiography Using a Tungsten Filter
- Author
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Eunhye Kim, Kenzo Muroi, Takahisa Koike, and Jungmin Kim
- Subjects
dose reduction ,pediatric chest radiography ,tungsten filter ,image quality optimization ,Technology ,Biology (General) ,QH301-705.5 - Abstract
The use of diagnostic radiology in pediatric patients has increased, and various positive effects have been reported, including methods to reduce radiation doses in children. Research has been conducted to preserve image quality while reducing exposure and doses in pediatric patients. This study aimed to measure four different filters to identify an optimized filter for pediatric patients. The experiment was conducted using four types of filters, including aluminum, copper, molybdenum, and tungsten. The optimal filter thickness was verified using a histogram to visually evaluate the spectrum by filter thickness, effective dose on a pediatric phantom, entrance skin dose, organ absorbed dose using the PC-based Monte Carlo (PCXMC) program version 2.0 simulation, figure of merit (FOM), and image quality. As a result of measuring the spectrum according to the tube voltage and the four types of filters, dose reduction and contrast improvement effects were obtained with a 0.05 mm tungsten filter. Additionally, effective entrance skin and organ absorbed dose decreased with the said filter. The aluminum, copper, and molybdenum filters demonstrated that the effective dose scarcely decreased even when the thickness was increased; meanwhile, the effective dose decreased when the tungsten filter was 0.05 mm. The FOM with a 0.05 mm tungsten increased by 91% in the lung field and 39% in the mediastinal field. The entrance skin and organ absorbed dose in pediatric patients can be reduced by removing low-energy photons that fail in image formation using a tungsten filter.
- Published
- 2022
- Full Text
- View/download PDF
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