Search results for "Myocardium"
showing 10 items of 365 documents
Prediction of long-term major events soon after a first ST-segment elevation myocardial infarction by cardiovascular magnetic resonance.
2016
Cardiovascular magnetic resonance (CMR) predicts combined clinical events in post-ST-segment elevation myocardial infarction (STEMI) patients. However, its contribution to predicting long-term major events (ME: cardiac death and non-fatal myocardial infarction [MI]) is unknown. We aimed to assess whether CMR predicts long-term MEs when performed soon after STEMI.We prospectively recruited 546 STEMI patients between 2004 and 2012. The Left ventricular (LV) ejection fraction (LVEF,%), infarct size (IS), edema, hemorrhage, microvascular obstruction, and myocardial salvage were quantified by CMR at pre-discharge. During a mean follow-up of 840 days, 57 ME events (10%; 23 cardiac deaths, 34 non-…
The prognostic role of CMR using global planimetric criteria in patients with excessive left ventricular trabeculation.
2021
Objectives: Although cardiovascular magnetic resonance (CMR) is widely used in the assessment of left ventricular non-compaction (LVNC), there are no universally accepted diagnostic criteria and limited data regarding their prognostic value. We assessed the long-term prognostic role of the planimetric global Grothoff’s criteria and of the CMR findings in predicting adverse cardiovascular events (CE). Methods: We prospectively enrolled 78 patients (46.7 ± 18.7 years, 33.3% females) with documented positive Jenni’s echocardiographic criteria for LVNC. Cine images were used to quantify function parameters and to assess for the presence of all four quantitative Grothoff’s criteria (global Groth…
[Myocardial echocardiography with intracoronary injection of contrast in post-infarction patients. Implications and comparison with angiography and m…
2004
We analyzed the safety and feasibility of myocardial echocardiography with intracoronary injection of contrast, its effect on left ventricular remodeling and systolic function, and its relationship with angiography and magnetic resonance imaging (MRI) for the evaluation of post-infarction coronary microcirculation.Thirty patients with a first ST-elevation myocardial infarction and a patent infarct-related artery were studied. Mean perfusion score of the infarcted area was analyzed with myocardial echocardiography. TIMI and Blush grades (angiography) were determined. Mean perfusion score (MRI-perfusion), end-diastolic volume index and ejection fraction were determined with MRI. At 6 months a…
Prognostic Value of Myocardial Ischemia and Necrosis in Depressed Left Ventricular Function: a Multicenter Stress Cardiac Magnetic Resonance Registry
2013
A B S T R A C T Introduction and objectives: The incremental prognostic value of inducible myocardial ischemia over necrosis derived by stress cardiac magnetic resonance in depressed left ventricular function is unknown. We determined the prognostic value of necrosis and ischemia in patients with depressed left ventricular function referred for dipyridamole stress perfusion magnetic resonance. Methods: In a multicenter registry using stress magnetic resonance, the presence ( 2 segments) of late enhancement and perfusion defects and their association with major events (cardiac death and nonfatal infarction) was determined. Results: In 391 patients, perfusion defect or late enhancement were p…
Nicotine receptors do not modulate the 3H-noradrenaline release from the isolated rat heart evoked by sympathetic nerve stimulation.
1982
Isolated rat hearts with the right sympathetic nerves attached were perfused at a constant flow rate of 7 ml/min with Tyrode's solution. (-)-3H-Noradrenaline (final concentration 10–13.9 nM) was infused for 10 min to label the noradrenaline stores. After wash-out the sympathetic nerves were stimulated electrically (3 Hz, 180 impulses, 1 ms, 20–30 mA) three times (S1–S3) at intervals of 15 min. 3H-Noradrenaline and its metabolites were determined by liquid scintillation counting according to Graefe et al. (1973). Both, nicotine 50 μM and p-aminophenethyltrimethylammonium (PAPETA) 30 μM, enhanced the 3H-noradrenaline overflow in the absence of nerve stimulation. The effect of PAPETA was bipha…
Resveratrol Reverses Endothelial Nitric-Oxide Synthase Uncoupling in Apolipoprotein E Knockout Mice
2010
A crucial cause of the decreased bioactivity of nitric oxide (NO) in cardiovascular diseases is the uncoupling of the endothelial NO synthase (eNOS) caused by the oxidative stress-mediated deficiency of the NOS cofactor tetrahydrobiopterin (BH(4)). The reversal of eNOS uncoupling might represent a novel therapeutic approach. The treatment of apolipoprotein E knockout (ApoE-KO) mice with resveratrol resulted in the up-regulation of superoxide dismutase (SOD) isoforms (SOD1-SOD3), glutathione peroxidase 1 (GPx1), and catalase and the down-regulation of NADPH oxidases NOX2 and NOX4 in the hearts of ApoE-KO mice. This was associated with reductions in superoxide, 3-nitrotyrosine, and malondiald…
Autoinhibition of noradrenaline release from the rat heart as a function of the biophase concentration. Effects of exogenous alpha-adrenoceptor agoni…
1984
1. Rat isolated perfused hearts with the right sympathetic nerves intact were loaded with 3H-(-)-noradrenaline. The nerves were stimulated with trains of 180 pulses at 3 Hz and at 10 min intervals. The overflow of 3H-noradrenaline and 3H-metabolites was determined by liquid scintillation spectrometry. 2. Clonidine (IC50 17 nM), oxymetazoline (IC50 63 nM), and α-methylnoradrenaline (apparent IC50 35 nM, determined in the presence of cocaine and propranolol) decreased the stimulation-evoked overflow of 3H-noradrenaline by 26, 49, and 78%, respectively, but not methoxamine up to 100 μM (propranolol present). Oxymetazoline and α-methyl-noradrenaline did not cause desensitization of the presynap…
Cardiac effects of isoliquiritigenin
1997
The effects of isoliquiritigenin on force of contraction (Fc), L-type Ca2+ current (I(Ca)) and intracellular Ca2+ concentration ([Ca2+]i) were investigated in rat ventricular heart muscle. Isoliquiritigenin increased Fc and I(Ca) and, after longer exposure times, resting tension and [Ca2+]i. The effect of isoliquiritigenin (100 microM) on I(Ca) was diminished by Rp-cAMPS (30 microM). 1H-[1,2,4]oxa- diazolo[4,3-a]quinoxalin-1-one (50 microM) did not influence the effects of isoliquiritigenin on Fc and I(Ca). The positive inotropic effects of isoprenaline and forskolin, but not of 3-isobutyl-1-methylxanthine, were potentiated by isoliquiritigenin (100 microM). In the presence of milrinone (10…
Mechanism of Block by 4-Aminopyridine of the Transient Outward Current in Rat Ventricular Cardiomyocytes
1998
The effects of 4-aminopyridine (4-AP) on the transient outward current (I to ) were investigated in rat ventricular cardiomyocytes at different values of intracellular pH (pH i ) and extracellular pH (pH o ). The 4-AP was administered either extracellularly (bath application) or intracellularly (diffusion from the intrapipette solution). The 4-AP diminished I to given either from inside or outside the cell membrane. The block by extracellularly applied 4-AP (4-AP o ) of the peak amplitude of I to was decreased by external acidification but increased by external alkalinization: conversely. the block by 4-AP o was decreased by internal alkalinization but increased by internal acidification. I…
Inhomogeneity of collagen organization within the fibrotic scar after myocardial infarction: results in a swine model and in human samples.
2015
We aimed to characterize the organization of collagen within a fibrotic scar in swine and human samples from patients with chronic infarctions. Swine were subjected to occlusion of the left anterior descending artery followed by reperfusion 1 week (acute myocardial infarction group) or 1 month (chronic myocardial infarction group) after infarction. The organization of the collagen fibers (Fast Fourier Transform of samples after picrosirius staining; higher values indicate more disorganization) was studied in 100 swine and 95 human samples. No differences in collagen organization were found between the acute and chronic groups in the core area of the scar in the experimental model. In the ch…