Search results for "Circulation"

Surgical treatment of chronic thromboembolic pulmonary hypertension.

2006

Chronic thromboembolic pulmonary hypertension is a commonly overlooked cause of physical incapacity and dyspnoea, with a higher incidence than is generally appreciated and a poor prognosis. The diagnosis can be suspected based on echocardiographic examinations and ventilation perfusion scanning of the lung. Pulmonary angiography still remains the gold standard for the diagnosis of thromboembolic pulmonary hypertension and the assessment of operability. Pulmonary endarterectomy is a complex surgical procedure, which provides permanent relief of thromboembolic pulmonary hypertension and cure for most of the patients. The operation resembles a true endarterectomy of the pulmonary artery branch…

Patent Foramen Ovale and Thromboembolic Complications

2010

The foramen ovale, an atrial septal defect which is essential in the fetal circulation, remains patent through adulthood in approximately 25% of the general population and so it represents the most common persistent abnormality of fetal origin. Patent foramen ovale (PFO) allows interatrial right-to-left blood shunting during those periods of the cardiac cycle in which the right atrial pressure exceeds the left one. An increasing number of pathological manifestations of PFO has been recently identified; among these, paradoxical systemic embolism, refractory hypoxemia in patients with right ventricular myocardium infarction or severe pulmonary disease, orthostatic oxygen desaturation in the r…

Quantitative myocardial perfusion magnetic resonance imaging: the impact of pulsatile flow on contrast agent bolus dispersion.

2011

Myocardial blood flow (MBF) can be quantified using T1-weighted first-pass magnetic resonance imaging (MRI) in combination with a tracer-kinetic model, like MMID4. This procedure requires the knowledge of an arterial input function which is usually estimated from the left ventricle (LV). Dispersion of the contrast agent bolus may occur between the LV and the tissue of interest. The aim of this study was to investigate the dispersion under conditions of physiological pulsatile blood flow, and to simulate its effect on MBF quantification. The dispersion was simulated in coronary arteries using a computational fluid dynamics (CFD) approach. Simulations were accomplished on straight vessels wit…

Effect of chest compressions only during experimental basic life support on alveolar collapse and recruitment

2007

Summary Aim The importance of ventilatory support during cardiac arrest and basic life support is controversial. This experimental study used dynamic computed tomography (CT) to assess the effects of chest compressions only during cardiopulmonary resuscitation (CCO-CPR) on alveolar recruitment and haemodynamic parameters in porcine model of ventricular fibrillation. Materials and methods Twelve anaesthetized pigs (26±1kg) were randomly assigned to one of the following groups: (1) intermittent positive pressure ventilation (IPPV) both during basic life support and advanced cardiac life support, or (2) CCO during basic life support and IPPV during advanced cardiac life support. Measurements w…

Microcirculation and mean arterial pressure: friends or foes?—reply

2020

Stabilization of Perivascular Mast Cells by Endothelial CNP (C-Type Natriuretic Peptide)

2020

Objective: Activated perivascular mast cells (MCs) participate in different cardiovascular diseases. Many factors provoking MC degranulation have been described, while physiological counterregulators are barely known. Endothelial CNP (C-type natriuretic peptide) participates in the maintenance of vascular barrier integrity, but the target cells and mechanisms are unclear. Here, we studied whether MCs are regulated by CNP. Approach and Results: In cultured human and murine MCs, CNP activated its specific GC (guanylyl cyclase)-B receptor and cyclic GMP signaling. This enhanced cyclic GMP–dependent phosphorylation of the cytoskeleton-associated VASP (vasodilator-stimulated phosphoprotein) and…

Intestinal ischaemia during cardiac arrest and resuscitation: comparative analysis of extracellular metabolites by microdialysis.

2003

Intestinal ischaemia is a major complication of shock syndromes causing translocation of bacteria and endotoxins and multiple organ failure in intensive care patients. The present study was designed to use microdialysis as a tool to monitor intestinal ischaemia after cardiac arrest and resuscitation in pigs. For this purpose, microdialysis probes were implanted in pig jejunal wall, peritoneum, skeletal muscle and brain, and interstitial fluid was obtained during circulatory arrest (induced by ventricular fibrillation) and after return of spontaneous circulation (ROSC). Cardiac arrest for 4 min caused a prolonged (60 min) reduction of blood flow in jejunal wall, muscle and brain as determine…

1-Year Outcomes After Edge-to-Edge Valve Repair for Symptomatic Tricuspid Regurgitation

2019

Abstract Objectives The purpose of this study was to evaluate procedural and 1-year clinical and echocardiographic outcomes of patients treated with tricuspid edge-to-edge repair. Background Transcatheter edge-to-edge repair has been successfully performed in selected patients with symptomatic tricuspid regurgitation (TR) and high risk for surgery, but outcome data are sparse. Methods This analysis of the multicenter international TriValve (Transcatheter Tricuspid Valve Therapies) registry included 249 patients with severe TR treated with edge-to-edge repair in compassionate and/or off-label use. Clinical and echocardiographic outcomes were prospectively collected and retrospectively analyz…

Differences in patients and lesion and procedure characteristics depending on the age of the coronary chronic total occlusion

2018

Introduction: Whether duration of chronic total occlusion (CTO) affects lesion and procedural characteristics remains largely unknown. Aim: To investigate whether CTO duration influences lesion characteristics and revascularization success. Material and methods: EuroCTO Registry data on patients who had CTO percutaneous coronary intervention between January 2015 and April 2017 were analyzed. Three groups were created based on occlusion age: 3 to 6 months (n = 1415), 7 to 12 months (n = 973), > 12 months (n = 1656). Results: Patients with greater CTO duration were older (63.0 (56.0–70.0); 63.0 (56.0–71.0); 66.0 (59.0–73.0) years respectively; p < 0.001), had more 3-vessel disease (32.2…

Ca2+ entry blockers inhibit prostaglandin F2 alpha-induced cerebrovascular contractile responses in goats.

1991

We examined the effects of extracellular Ca2+ withdrawal and of Ca2+ entry blockers on goat cerebrovascular responses to prostaglandin F2 alpha (PGF2 alpha). We measured isometric tension in isolated middle cerebral arteries, and cerebral blood flow (CBF) in unanesthetized animals. PGF2 alpha produced concentration-dependent contractions of isolated arteries. The contractions were partially inhibited by incubation in Ca(2+)-free medium (by 63.1 +/- 1.8% without ethyleneglycol-bis-(beta-amino-ethylether)-N,N,N',N'-tetra-a cetate (EGTA), and by 82.4 +/- 3.7% with EGTA). The Ca2+ entry blockers inhibited PGF2 alpha-elicited contraction and relaxed PGF2 alpha-precontracted arteries (nicardipine…