Publications by authors named "Naoto Miyagi"

Cardiac involvement has been reported in patients with coronavirus disease 2019 (COVID-19). We herein report a 41-year-old man who presented with recurrent paroxysmal atrioventricular block without showing significant cardiac injuries or comorbidities. The patient was diagnosed with COVID-19 and admitted to our hospital, where he was noted to have paroxysmal atrioventricular block.

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We performed infarct exclusion repair of ventricular septal perforation(VSP) in a 63-year-old woman who was diagnosed with acute myocardial infarction(AMI) of the inferior wall. As VSP existed behind a fragile posterior papillary muscle, we excised the papillary muscle and sutured a bovine pericardial patch to exclude the infarct area of the whole septum and a part of the inferior wall. Mitral valve replacement and coronary artery bypass were also performed.

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Objectives: Recommendations for extracorporeal cardiopulmonary resuscitation (ECPR) state that appropriate patient selection is important for the sake of efficacy and cost-effectiveness of ECPR. It is not known whether first documented rhythm plays a prominent role in economic outcomes of patients with cardiac arrest who received ECPR.

Methods And Results: We reviewed the medical records of 120 consecutive patients who received extracorporeal membrane oxygenation (ECMO) assisted CPR due to refractory circulatory collapse between 2008 and 2016 in Urasoe General Hospital.

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Background: Rejection of Gal-free (GTKO) donor pig cardiac xenografts is strongly associated with vascular non-Gal antibody binding, endothelial cell (EC) injury, and activation and microvascular thrombosis. We adopted a pig-to-SCID/beige small animal transplant model to compare the pathogenicity of baboon and human anti-pig antibody.

Methods: Wild-type (GT(+) ) or GTKO porcine coronary arteries (PCAs) were transplanted into the infrarenal aorta of SCID/beige mice.

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The external lumen of a stent [defined as extra-stent lumen (ESL)] assessed by optical coherence tomography (OCT) may be related to the risk of thrombus formation after sirolimus-eluting stent (SES) implantation. An everolimus-eluting stent (EES) might provide relatively minimal inflammatory reaction and appropriate neointimal coverage. The purpose of this study was to compare the neointimal thickness and ESL between SES and EES.

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Background: Optimal ring size in tricuspid annuloplasty (TAP) surgery to treat functional tricuspid regurgitation (TR) was investigated because optimal ring size remains undefined.

Methods And Results: Sixty seven patients who underwent TAP at our institution were retrospectively studied. Tricuspid Annuloplasty Ring size Index (TARI) was defined as implanted tricuspid annuloplasty ring size divided by body surface area (BSA).

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We have evaluated the feasibility of a newly developed single-use, magnetically levitated centrifugal blood pump, MedTech Mag-Lev, in a 3-week extracorporeal membrane oxygenation (ECMO) study in calves against a Medtronic Bio-Pump BPX-80. A heparin- and silicone-coated polypropylene membrane oxygenator MERA NHP Excelung NSH-R was employed as an oxygenator. Six healthy male Holstein calves with body weights of about 100 kg were divided into two groups, four in the MedTech group and two in the Bio-Pump group.

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Purpose: Postoperative atrial fibrillation (AF) is a common complication of cardiac surgery that is associated with an increased incidence of other complications. The goal of this prospective randomized study was to evaluate the effect of ultra-low dose landiolol hydrochloride for prevention of AF after off-pump coronary artery bypass grafting (CABG).

Methods: The subjects were 47 patients who underwent isolated CABG and were randomly divided into those who received landiolol from ICU admission until the beginning of oral drug intake (Group L) and those administered diltiazem hydrochloride over the same period (Group D).

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Purpose: We have been using the flanged composite aortic prosthesis and Carrel button technique to re-attach the coronary ostia in aortic root replacement procedures at our institution over the last twenty five years. Our objective was to evaluate the long-term results of aortic root replacement with this technique.

Methods: A total of 73 patients from January 1984 to August 2010 were included in this study.

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Non-ischemic mitral regurgitation( MR) is classified in degenerative MR, infective endocarditis( IE) and rheumatic MR. For degenerative MR, although 100% achievement of successful mitral valve plasty (MVP), it still important to evaluate mitral morphology preoperatively and to select suitable procedure.MR due to IE, the most important thing is to exclude vegetation completely.

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Background: Transgenic expression of human complement regulatory proteins reduces the frequency of hyperacute rejection (HAR) in Gal-positive cardiac xenotransplantation. In this study, we examined the impact of human CD55 (hCD55) expression on a Gal knockout (GTKO) background using pig-to-primate heterotopic cardiac xenotransplantation.

Methods: Cardiac xenotransplantation was performed with GTKO (group 1; n=6) and GTKO.

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Basic mechanism of ischemic mitral regurgitation (MR) is augmented leaflet tethering because of the out ward displacement of the papillary muscle by the left ventricular dilation. In 30% of ischemic MR, subvalvular procedure is necessary to eliminate MR. We propose subvalvular procedure aiming at a comprehensive remodeling of the entire mitral complex.

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Owing to development of device technology, off-pump coronary artery bypass grafting (OPCAB) has become a safe, reproducible and reliable procedure. Surgeons must understand the advantages and limitations of each device and select appropriate devices in individual case to avoid device-related complication and a waste of cost. The directions and pitfalls of heart positioners, stabilizers and proximal anastomotic devices were described.

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Purpose: The aim of this observational study was to determine the incidence of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) in patients with or without preoperative pravastatin treatment.

Methods: Between January 2005 and December 2007, a total of 195 patients (39 women, mean age 66.5 +/- 10.

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Background: In this investigation we studied the efficacy and durability of recombinant adeno-associated virus serotype 9 (rAAV9) vector-mediated gene transfer to the transplanted rat heart.

Methods: A rAAV9-CMV-lacZ vector diluted in cold (4 degrees C) University of Wisconsin solution was used to perfuse the rat coronary vasculature for 20 minutes prior to syngeneic heterotopic transplantation. Perfusion experiments (six groups, n = 3/group) were performed without rAAV9 and at four separate doses ranging from 2 x 10(9) to 2 x 10(12) viral genomes/ml.

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Background: We evaluated the feasibility of noninvasive micro-single photon emission computed tomography (SPECT)/computed tomography (CT) imaging and quantification of cardiac gene expression after sodium iodide symporter (hNIS) gene transfer in cardiac transplantation.

Methods: Donor rat hearts were perfused ex vivo with adenovirus expressing hNIS (Ad-hNIS), Ad-Null, or University of Wisconsin (UW) solution prior to heterotopic transplantation into syngeneic recipients. In the first group of recipients, imaging of the transplanted hearts with micro-SPECT/CT on day 5 was followed by immediate explant of the organs for ex vivo analyses.

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Background: Antiarrhythmic agents are considered to have significant effects on the defibrillation energy requirement, so this study investigated the effects of nifekalant on defibrillation.

Methods And Results: Forty-two patients with persistent atrial fibrillation (AF) underwent electrical cardioversion via intracardiac electrode catheters prior to and after the intravenous administration of nifekalant. The success rate of the defibrillation and change in the defibrillation threshold using sequential incremental defibrillation energy deliveries was investigated.

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Background: Adenovirus serotype 5 has remained the pre-eminent vector in pre-clinical gene therapy applications in cardiac transplantation. Concerns over the potential effects of adenoviral vectors on the later development of cardiac allograft vasculopathy (CAV) are addressed in this study.

Methods: Hearts (n = 22) harvested from Brown Norway rats were perfused ex vivo with either University of Wisconsin (UW) solution with no virus, Ad-CMV-LacZ or Ad-CMV-Null.

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Objective: We studied the concordance of transgene expression in the transplanted heart using bicistronic adenoviral vector coding for a transgene of interest (human carcinoembryonic antigen: hCEA - beta human chorionic gonadotropin: betahCG) and for a marker imaging transgene (human sodium iodide symporter: hNIS).

Methods: Inbred Lewis rats were used for syngeneic heterotopic cardiac transplantation. Donor rat hearts were perfused ex vivo for 30 min prior to transplantation with University of Wisconsin (UW) solution (n=3), with 10(9) pfu/ml of adenovirus expressing hNIS (Ad-NIS; n=6), hNIS-hCEA (Ad-NIS-CEA; n=6) and hNIS-betahCG (Ad-NIS-CG; n=6).

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Introduction: Endomyocardial biopsy is the standard means of establishing cardiac allograft rejection diagnosis. The efficacy of this procedure in xenotransplantation has not been determined. In this study we compare the histology of right ventricular endomyocardial biopsy specimens with the corresponding full cross sections of explanted right ventricle (RV).

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Efficient durable viral vector transduction of the transplanted heart remains elusive. This study assesses the potential of recombinant adeno-associated virus (rAAV) mediated gene delivery to the transplanted rat heart. rAAV serotype 1, 2 and 5 vectors encoding the green fluorescent protein (GFP) gene (1 x 10(11) viral particles/ml) were diluted in cold University of Wisconsin solution and circulated through the coronary vasculature of the donor organs for 30 min before syngeneic rat heterotopic heart transplantation was performed.

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Isolated tricuspid valve regurgitation (TR) is a rare clinical entity. We report 2 patients, 80 and 74-year-old with isolated TR. They underwent valve replacement with the Carpentier-Edwards bioprosthesis because of resistance to medical treatment.

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Objective: A radial artery (RA) graft is frequently used for coronary artery bypass grafting (CABG), but little information exists regarding the early- and mid-term patency associated with the harvesting procedure. The objective of this study is to compare the early- and mid-term patency of the RA graft obtained using non-skeletonized and skeletonized harvesting.

Methods: Altogether, 131 patients and 159 anastomoses were studied.

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A 62-year-old man who underwent coronary artery bypass grafting (CABG) [left internal thoracic artery (LITA)-left anterior descending (LAD), saphenous vein graft (SVG) right coronary artery (RCA)] 13 years previously developed angina pectoris and congestive heart failure because of occlusion of SVG and native vessels. Coronary angiography (CAG) revealed that inflow to the coronary artery remained only from LITA. Repeat off-pump CABG (OPCAB) with SVG to the circumflex artery via left thoracotomy was performed.

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