A5007483946- Heart Rate Variability and Autonomic Control
- Cardiovascular Function and Risk Factors
- Cardiac electrophysiology and arrhythmias
- Vagus Nerve Stimulation Research
- Neuroscience of respiration and sleep
- Cardiovascular and exercise physiology
- Non-Invasive Vital Sign Monitoring
- Pulmonary Hypertension Research and Treatments
- Nitric Oxide and Endothelin Effects
- Mechanical Circulatory Support Devices
- Renin-Angiotensin System Studies
- Cardiovascular Syncope and Autonomic Disorders
- Hemodynamic Monitoring and Therapy
- Cardiovascular Health and Disease Prevention
- Cardiac Fibrosis and Remodeling
- Cardiac Arrhythmias and Treatments
- Eicosanoids and Hypertension Pharmacology
- EEG and Brain-Computer Interfaces
- Cardiac Structural Anomalies and Repair
- Cardiac Ischemia and Reperfusion
- Receptor Mechanisms and Signaling
- Adipose Tissue and Metabolism
- Hormonal Regulation and Hypertension
- Cardiac Imaging and Diagnostics
- Coronary Interventions and Diagnostics
Kyushu University
2015-2025
Sunagawa City Medical Center
1982-2024
University of the Ryukyus
2024
Kyushu University Hospital
2008-2018
Fukuoka University
2005-2016
St Mary's Hospital
2016
Japanese Red Cross Fukuoka Hospital
2016
Kyushu Hospital
2016
Yao Tokushukai General Hospital
2014
UConn Health
2008-2013
We developed a framework of analysis to predict the stroke volume (SV) resulting from complex mechanical interaction between ventricle and its arterial system. In this analysis, we characterized both left system by their end systolic pressure (Ps)-SV relationships predicted SV intersection two relationship lines. The final output was formula that gives for given preload as function ventricular properties (Ees, V0, ejection time) impedance (modeled in terms 3-element Windkessel). To test...
Diminished cardiac vagal activity and higher heart rate predict a high mortality of chronic failure (CHF) after myocardial infarction. We investigated the effects electrical stimulation vagus nerve on remodeling long-term survival in an animal model CHF large infarction.Two weeks ligation left coronary artery, surviving rats were randomized to vagal- sham-stimulated groups. Using implantable miniature radio-controlled stimulator, we stimulated right for 6 weeks. The intensity was adjusted...
We examined the quantitative influence of carefully controlled alterations in end-diastolic volume and afterload resistance on multiple simultaneously determined ejection isovolumetric phase indexes left ventricular contractile function 23 isolated supported canine ventricles. The load change each index was compared with its sensitivity to inotropic stimulation, this turn contrasted response end-systolic pressure-volume relationship (ESPVR). Experimental data demonstrated various degrees...
In a previous analysis of ventricular arterial interaction (Sunagawa et al., 1983), we represented the left ventricle as an elastic chamber which periodically increases its volume elastance to value equal slope linear end-systolic pressure-volume relationship. Similarly, load property was by effective is pressure-stroke Since maximal transfer potential energy from one another occurs when they have elastance, hypothesized that would do external work if and were equal. We tested this...
Background— Prognosis of ischemic cardiomyopathy still remains poor because the lack effective treatments. To develop a noninvasive therapy for disorder, we examined in vitro and vivo effects extracorporeal shock wave (SW) that could enhance angiogenesis. Methods Results— SW treatment applied to cultured human umbilical vein endothelial cells significantly upregulated mRNA expression vascular growth factor its receptor Flt-1 vitro. A porcine model chronic myocardial ischemia was made by...
Mitochondrial DNA (mtDNA) copy number is decreased not only in mtDNA-mutation diseases but also a wide variety of acquired degenerative and ischemic diseases. transcription factor A (TFAM) essential for mtDNA replication. Myocardial TFAM expression both cardiac failure. However, the functional significance has been established this disease state.We have now addressed question by creating transgenic (Tg) mice that overexpress human gene examined whether could protect heart from deficiencies...
Mitochondrial oxidative stress and damage play major roles in the development progression of left ventricular (LV) remodeling failure after myocardial infarction (MI). We hypothesized that overexpression mitochondrial antioxidant, peroxiredoxin-3 (Prx-3), could attenuate this deleterious process.We created MI 12- to 16-week-old, male Prx-3-transgenic mice (TG+MI, n=37) nontransgenic wild-type (WT+MI, n=39) by ligating coronary artery. Prx-3 protein levels were 1.8 times higher hearts from TG...
ST Elevation in Brugada Syndrome. Introduction : syndrome is characterized by an segment elevation leads V 1 ‐V 3 and a high incidence of ventricular fibrillation (VF). A mutation cardiac Na + channel gene, SCN5A , has been linked to syndrome, sodium blockers have shown be effective unmasking the when concealed. The aim this study was examine effects on elevation, QRS, corrected QT (QTc) interval, arrhythmias patients with syndrome. Methods Results We examined three different (flecainide,...
Objective— Resveratrol (3,5,4′-trihydroxystilbene), a polyphenol found in red wine, is known to activate sirtuin1 (SIRT1), longevity gene. Previous studies have demonstrated that resveratrol extends the life span of diverse species through activation SIRT1. It was also reported inhibition angiotensin II function by type I receptor (AT1R) antagonist prolonged rat span. We, therefore, hypothesized may inhibit renin-angiontein system and examined whether affects AT1R expression vascular smooth...
In Brief Objective Prognosis of severe coronary artery disease with no indication percutaneous intervention or bypass grafting remains poor. We have recently demonstrated that shock wave therapy effectively induces neovascularization and improves myocardial ischemia in a porcine model vivo. Methods With permission from the Ethical Committee our Institute, we treated nine patients end-stage (55–82 years old, five men four women) cardiac (200 shots/spot at 0.09 mJ/mm2 for 20–40 spots, 3 times...
To study the end-systolic pressure-volume relationship of left ventricle ejection against physiological afterload, we imposed seven simulated arterial impedances on excised canine ventricles connected to a newly developed servo-pump system. We set each impedance parameters (resistance, capacitance, and characteristic impedance) 50, 100, 200% normal value (resistance: 3 mm Hg sec/ml; capacitance: 0.4 ml/mm Hg; impedance: 0.2 sec/ml), while leaving other normal. Under given impedance, was...
The relationship between peak isovolumic developed pressure (Pmax) and end-diastolic volume can indicate ventricular contractility. Therefore, we propose a practical method to estimate Pmax from the curve of an ejecting contraction left ventricle. For estimation, first considered ventricle linear time varying hydromotive source (HMP(t)) coupled in series with internal impedance. To formulate HMP(t) Fourier analyzed curves obtained under various conditions six dogs. Since higher order...
Mitochondrial DNA (mtDNA) is highly susceptible to injury induced by reactive oxygen species (ROS). During aging, mutations of mtDNA accumulate induce dysfunction the respiratory chain, resulting in enhanced ROS production. Therefore, age-dependent memory impairment may result from oxidative stress derived chain. transcription factor A (TFAM) now known have roles not only replication but also its maintenance. We herein report that an overexpression TFAM HeLa cells significantly inhibited...
We studied the effects of regional ischemia on left ventricular isovolumic end-systolic pressure-volume relationship (ESPVR) in six excised, blood-perfused canine ventricles. created different extents by ligating various branches coronary arteries while keeping arterial pressure constant (80 mm Hg). The extent (Rm) relative to total mass myocardium was determined myocardial blood flow measured radioactive microsphere technique. With ischemia, ESPVR shifted rightward without significant...
Preventing atherosclerotic plaque destabilization and rupture is the most reasonable therapeutic strategy for acute myocardial infarction. Therefore, we tested hypotheses that (1) inflammatory monocytes play a causative role in (2) nanoparticle-mediated delivery of pitavastatin into circulating inhibits rupture.We used model brachiocephalic arteries apolipoprotein E-deficient (ApoE(-/-)) mice fed high-fat diet infused with angiotensin II. The adoptive transfer CCR2(+/+)Ly-6C(high)...
Pulmonary arterial hypertension (PAH) is an intractable disease of the small pulmonary artery that involves multiple inflammatory factors. We hypothesized a redox-sensitive transcription factor, nuclear factor kappaB (NF-kappaB), which regulates important cytokines, plays pivotal role in PAH. investigated activity NF-kappaB explanted lungs from patients with PAH and rat model also examined nanotechnology-based therapeutic intervention model. Immunohistochemistry results indicated increased...
Background Mitochondrial DNA (mtDNA) copy number decreases in animal and human heart failure (HF), yet its role cardiomyocytes remains to be elucidated. Thus, we investigated the cardioprotective function of increased mtDNA resulting from overexpression transcription factor A mitochondria (TFAM) or Twinkle helicase volume overload (VO)-induced HF. Methods Results Two strains transgenic (TG) mice, one overexpressing TFAM other helicase, exhibit an approximately 2-fold equivalent increase...
Acute myocardial infarction remains a leading cause of chronic heart failure. Excessive oxygen demand relative to supply is the fundamental mechanism infarction. We thus hypothesized that left ventricular (LV) mechanical unloading by total support transvascular LV assist device Impella could minimize demand, thereby reducing infarct size and preventing subsequent failure.In 20 dogs, we ligated anterior descending coronary artery for 180 minutes then reperfused. introduced from 60 after onset...
Objective— Inflammatory monocytes/macrophages produce various proteinases, including matrix metalloproteinases, and degradation of the extracellular by these activated proteinases weakens mechanical strength atherosclerotic plaques, which results in a rupture plaque. Peroxisome proliferator–activated receptor-γ induces polarity shift toward less inflammatory phenotypes has potential to prevent plaque ruptures. Therefore, we hypothesized that nanoparticle-mediated targeted delivery peroxisome...