Search results for "microcirculation"

Regulation of Oxygen Distribution in Tissues by Endothelial Nitric Oxide

2009

Nitric oxide (NO) decreases cellular oxygen (O 2 ) consumption by competitively inhibiting cytochrome c oxidase. Here, we show that endogenously released endothelial NO, either basal or stimulated, can modulate O 2 consumption both throughout the thickness of conductance vessels and in the microcirculation. Furthermore, we have shown that such modulation regulates O 2 distribution to the surrounding tissues. We have demonstrated these effects by measuring O 2 consumption in blood vessels in a hypoxic chamber and O 2 distribution in the microcirculation using the fluorescent oxygen-probe Ru(phen) 3 2+ . Removal of NO by physical or pharmacological means, or in eNOS −/− mice, abolishes this …

Red blood cell deformability in multiple myeloma1.

2018

The aim of this study was the evaluation of the erythrocyte deformability in multiple myeloma (MM). We enrolled 29 MM patients and we evaluated, on fasting venous blood, the erythrocyte deformability, expressed as elongation index, and examined using the diffractometric method. By comparing normal controls and MM patients, a significant decrease in erythrocyte deformability, especially at low shear stresses, was found. In this research paper we evaluated all the hypothesis for a possible explanation of the behaviour of red blood cell deformability in MM, even considering how the alteration of erythrocyte deformability worsens the microcirculatory flow in these patients in association with t…

Tissue optical perfusion pressure: a simplified, more reliable, and faster assessment of pedal microcirculation in peripheral artery disease

2020

Oscillometry is an alternative to continuous-wave Doppler (cw-Doppler) to determine peripheral artery disease (PAD) severity using the ankle-brachial index (ABI). cw-Doppler ABI differentiates systolic pressure of ATP and ADP where either one of both values in most patients is higher (high) and the other value is lower (low). In contrast, oscillometric ABI measures the strongest signal and hence misses the lower value. Both do not take pedal perfusion into consideration. Simultaneous determination of tissue microperfusion cares for pedal PAD. ABI was determined by cw-Doppler and oscillometry. Tissue optical perfusion pressure (TOPP) was taken from the first toe using photoplethysmography. 3…

Angiographic Evaluation of Coronary Microvascular Dysfunction in Patients with Heart Failure and Preserved Ejection Fraction

2015

Background The aim of this study was to evaluate myocardial perfusion and coronary blood flow through validated angiography indices to assess whether there is greater MVD in patients with microvascular angina and HFPEF compared to those who do not have. Methods Our study was performed on a population of 286 patients with stable angina that underwent coronary angiography and echocardiography. They showed epicardial coronary arteries free from stenosis. We divided the sample into two categories: patients with HFPEF and those without. We calculated indices for each patient based on angiographic images, including TFC, MBG, and TMBS. Results Our sample compared two groups: HFPEF (n = 155) and no…

Prognostic Value of Strain by Tissue Tracking Cardiac Magnetic Resonance After ST-Segment Elevation Myocardial Infarction

2018

The aim of this study was to evaluate the prognostic value of strain as assessed by tissue tracking (TT) cardiac magnetic resonance (CMR) soon after ST-segment elevation myocardial infarction (STEMI).The prognostic value of myocardial strain as assessed post-STEMI by TT-CMR is unknown.The authors studied the prognostic value of TT-CMR in 323 patients who underwent CMR 1 week post-STEMI. Global (average of peak segmental values [%]) and segmental (number of altered segments) longitudinal (LS), circumferential, and radial strain were assessed using TT-CMR. Global and segmental strain cutoff values were derived from 32 control patients. CMR-derived left ventricular ejection fraction, microvasc…

Abnormal Myocardial Perfusion After Infarction in Patients With Persistent TIMI Grade-3 Flow. Only an Acute Phenomenon?

2007

Introduction and objectives It has been suggested that abnormal perfusion as derived from cardiovascular magnetic resonance imaging (CMR) is a transient dysfunction of microcirculation after myocardial infarction (MI) with TIMI 3 flow. We hypothesized that defects of myocardial perfusion may persist during the following months. Methods Forty-seven patients with MI and sustained TIMI 3 flow underwent intracoronary myocardial contrast echocardiography (MCE) 1 week and 6 months after infarction. Abnormal perfusion by MCE was regarded as >1 hypoperfused segment. Results At one week, 20 patients showed abnormal perfusion as derived from MCE. At six months 10 patients displayed chronic abnormal p…

Prognosis in patients with microvascular angina: A clinical follow-up

2019

Prognostic Value of Microvascular Obstruction and Infarct Size, as Measured by CMR in STEMI Patients

2014

The aim of this study was to evaluate the value of microvascular obstruction (MO) and infarct size as a percentage of left ventricular mass (15%LV), as measured by contrast-enhanced cardiac magnetic resonance, in predicting major cardiovascular adverse events (MACE) at 2 years in patients with ST-segment elevation myocardial infarction reperfused by primary percutaneous coronary intervention. Individual data from 1,025 patients were entered into the pooled analysis. MO was associated with the occurrence of MACE, defined as a composite of cardiac death, congestive heart failure, and myocardial re-infarction (adjusted hazard ratio: 3.74; 95% confidence interval: 2.21 to 6.34). IS% LV >= 25% w…

Permanence of Modifications in Oral Microcirculation in Ex-Smokers.

2019

Background: The aim of this study was to assess the long-term effects of smoking and to investigate the permanence of this damage to the oral microcirculation. Material/Methods: We recruited 75 patients and divided them into 3 groups: group 1 was composed of 25 healthy non-smokers, group 2 was composed of 25 healthy current smokers, and group 3 was composed of 25 healthy ex-smokers. Video-capillaroscopic examination was performed on all patients. The video-capillaroscopic investigation was performed on patients in sitting position, always with the same light source, at the same room temperature (23°C), in the morning, with the same operator (GAS), and was repeated many times for every area …

Rheopheresis in Patients with Critical Limb Ischemia--Results of an Open Label Prospective Pilot Trial

2005

Rheopheresis is a specifically designed application of double filtration plasmapheresis, for extracorporeal treatment of microcirculatory disorders. Safety and efficacy of Rheopheresis for wound healing and skin oxygenation were investigated in patients with critical limb ischemia. Twelve patients of Fontaine stage III-IV were treated with a series of 10 Rheopheresis sessions over 17 weeks. Transcutaneous oxygen pressure (tcpO(2)) and ankle-brachial index (ABI) were repeatedly determined to monitor the effects of the Rheopheresis treatment series on microcirculation and skin blood flow. Laboratory parameters of blood rheology were measured in addition to safety parameters and course of the …