A5102716617- Heart Rate Variability and Autonomic Control
- Cardiovascular Function and Risk Factors
- Cardiac electrophysiology and arrhythmias
- Vagus Nerve Stimulation Research
- Hemodynamic Monitoring and Therapy
- Mechanical Circulatory Support Devices
- Non-Invasive Vital Sign Monitoring
- Heart rate and cardiovascular health
- Cardiac Structural Anomalies and Repair
- Cardiac Arrest and Resuscitation
- Traumatic Brain Injury and Neurovascular Disturbances
- Pulmonary Hypertension Research and Treatments
- Cardiovascular and exercise physiology
- Neuroscience of respiration and sleep
- Cardiovascular Syncope and Autonomic Disorders
- Receptor Mechanisms and Signaling
- Cardiac Valve Diseases and Treatments
- Intracranial Aneurysms: Treatment and Complications
- Cerebrovascular and Carotid Artery Diseases
- Acute Ischemic Stroke Management
- Cardiovascular Health and Disease Prevention
- Nicotinic Acetylcholine Receptors Study
- Heart Failure Treatment and Management
- Cardiac Imaging and Diagnostics
- EEG and Brain-Computer Interfaces
National Cerebral and Cardiovascular Center
2016-2025
Turku University Hospital
2018
University of Turku
2018
May Institute
2018
Isuzu Advanced Engineering Center (Japan)
2009
Art Research Centre of the Slovak Academy of Sciences
2006
Nagoya University
1989-2003
Cardiovascular Research Center
2002
Kumamoto University
1999-2000
Institute of Brain and Blood Vessels
1978-1995
Cerebrovascular reactivity to CO2 inhalation and voluntary hyperventilation was studied in seven normotensive subjects nine hypertensive patients without clinical or angiographical signs of arteriosclerosis. Cerebral blood flow (CBF) measured by the intracarotid 133Xe clearance method calculated as initial slope index. Three five CBF measurements were made each patient PaCO2 range 20 55 mm Hg. No difference observed between patients, either during hyperventilation. The shape CBF:PaCO2 curve...
Positive end-expiratory pressure (PEEP) improves respiratory conditions. However, the complex interaction between PEEP and hemodynamics in heart failure patients makes it challenging to determine appropriate settings. In this study, we developed a framework for impact of on considering cardiac function, by integrating generalized circulatory equilibrium framework, validated assessing its ability accurately predict PEEP-induced hemodynamics. eight dogs, was increased stepwise, hemodynamic...
Endotracheal intubation plays a crucial role in airway management mice. Transoral endotracheal (TEI) offers less invasive alternative to tracheostomy and is more ideal for chronic experiments. Despite the development of various TEI techniques mice, lack accessible well-established methods that do not require specialized equipment hinders routine research. We developed feasible highly successful method C57BL/6JJcl mice using combination commercially available research equipment. A success...
Sympathetic activation during orthostatic stress is accompanied by a marked increase in low-frequency (LF, approximately 0.1-Hz) oscillation of sympathetic nerve activity (SNA) when arterial pressure (AP) well maintained. However, LF SNA development neurally mediated syncope remains unknown. Ten healthy subjects who developed head-up tilt (HUT)-induced and 10 age-matched nonsyncopal controls were studied. Nonstationary time-dependent changes calf muscle (MSNA, microneurography), R-R...
Vagal nerve stimulation has been suggested to ameliorate left ventricular (LV) remodeling in heart failure. However, it is not known whether and what degree vagal affects matrix metalloproteinase (MMP) tissue inhibitor of MMP (TIMP) myocardium, which are play crucial roles LV remodeling. We therefore investigated the effects electrical efferent on myocardial expression activation MMPs TIMPs a rabbit model ischemia-reperfusion (I/R) injury. Anesthetized rabbits were subjected 60 min coronary...
We estimated open-loop dynamic characteristics of the carotid sinus baroreflex in normal control rats and chronic heart failure (CHF) after myocardial infarction. First, neural arc transfer function from pressure to splanchnic sympathetic nerve activity (SNA) its corresponding step response were examined. Although steady-state was attenuated CHF, negative peak time did not change significantly, suggesting preserved characteristics. Next, peripheral SNA arterial (AP) The initial slope reduced...
Background: Vagal activation by electrical stimulation has been shown to improve the long-term survival of rats with chronic heart failure (CHF) after extensive myocardial infarction (MI). Acetylcholinesterase inhibition increases synaptic acetylcholine, and can disproportionately increase vagal tone. To develop an alternative therapy for CHF using a clinically available drug, present study investigated whether oral donepezil, acetylcholinesterase inhitor, could reproduce beneficial effects...
The acetylcholinesterase inhibitor donepezil restores autonomic balance, reduces inflammation, and improves long-term survival in rats with chronic heart failure (CHF) following myocardial infarction (MI). As arterial hypertension is associated a significant risk of cardiovascular death, we investigated the effectiveness treating CHF spontaneously hypertensive (SHR). was induced SHR by inducing permanent MI. After 2 weeks, surviving were randomly assigned to sham-operated (SO), untreated...
A novel framework of circulatory equilibrium was developed by extending Guyton's original concept. In this framework, venous return (CO(V)) for a given stressed volume (V) characterized flat surface as function right atrial pressure (P(RA)) and left (P(LA)) follows: CO(V) = V/W - G(S)P(RA) G(P)P(LA), where W, G(S), G(P) denote linear parameters. seven dogs under total heart bypass, CO(V), P(RA), P(LA), V were varied to determine the three parameters in each animal with use multivariate...
MR diagnosis of subacute and chronic subarachnoid hemorrhage: comparison with CT.T Ogawa, A Inugami, H Fujita, J Hatazawa, E Shimosegawa, K Noguchi, T Okudera, I Kanno, Uemura SuzukiAudio Available | Share
Accurate prediction of cardiac output (CO), left atrial pressure (PLA), and right (PRA) is a prerequisite for management patients with compromised hemodynamics. In our previous study (Uemura et al. Am J Physiol Heart Circ 286: H2376-H2385, 2004), we demonstrated circulatory equilibrium framework, which permits the CO, PLA, PRA once venous return surface integrated CO curve are known. Inasmuch as also showed that can be estimated from single-point measurements, hypothesized similar estimation...
A transfer function from baroreceptor pressure input to sympathetic nerve activity (SNA) shows derivative characteristics in the frequency range below 0.8 Hz rabbits. These contribute a quick and stable arterial (AP) regulation. However, if hold up heart rate frequency, pulsatile will yield markedly augmented SNA signal. Such signal would saturate baroreflex transduction, thereby disabling regulation of AP. We hypothesized that gain at be much smaller than predicted extrapolating...
Static characteristics of the baroreflex neural arc from pressure input to sympathetic nerve activity (SNA) show sigmoidal nonlinearity, whereas its dynamic approximate a derivative filter where magnitude SNA response becomes greater as frequency increases. To reconcile static nonlinear and linear components, we examined effects amplitude on apparent transfer function arc. In nine anesthetized rabbits, perturbed isolated carotid sinus by using binary white noise while varying among 5, 10,...
Transmural distribution of viable myocardium in the ischemic has not been quantified and fully elucidated. To address this issue, we evaluated transmural myocardial strain profile (TMSP) dogs with infarction using a newly developed tissue imaging. TMSP was obtained from posterior wall at epicardial left ventricular short-axis view 13 anesthetized open-chest dogs. After control measurements, circumflex coronary artery occluded for 90 min to induce subendocardial (SMI). Subsequently, latex...
Although baroreceptors are known to reset operate in a higher pressure range spontaneously hypertensive rats (SHR), the total profile of dynamic arterial (AP) regulation remains be clarified. We estimated open-loop transfer functions carotid sinus baroreflex SHR and Wistar Kyoto (WKY) rats. Mean input pressures were set at 120 (WKY₁₂₀ SHR₁₂₀) 160 mmHg (SHR₁₆₀). The neural arc function from efferent splanchnic sympathetic nerve activity (SNA) revealed derivative characteristics both WKY SHR....
We examined whether the ACh concentration measured by cardiac microdialysis provided information on left ventricular levels under a variety of vagal stimulatory and modulatory conditions in anesthetized cats. Local administration KCl ( n = 5) ouabain 7) significantly increased dialysate to 4.3 ± 0.8 7.3 1.3 nmol/l, respectively, from baseline value 0.6 0.5 nmol/l. Intravenous phenylbiguanide phenylephrine 6) 5.4 0.9 6.0 1.5 suggesting that Bezold-Jarisch arterial baroreceptor reflexes...