Publications by authors named "Juan C Porres"

Purpose: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality.

Methods: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.

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Our aim was to analyse endothelial hypoxic preconditioning after hypoxia-reperfusion (HR). Endothelial functionality was analysed through the vasorelaxation responses to acetylcholine (Ach) and the level of serine1177 phosphorylated endothelial nitric oxide synthase (eNOS) (ser1177-eNOS) measured by Western blot in in vitro hypoxic preconditioned (P + HR) isolated rat aortic segments. Relaxation in response to Ach was reduced in phenylephrine-precontracted aortic segments after HR (control: IC50, 5 +/- 2.

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Mapping techniques are used to study the significance of the morphological patterns of the electrograms (EGMs) obtained during VF in an experimental model. In 24 isolated rabbit heart preparations recordings were made of activation during VF using a multiple electrode (121 unipolar electrodes) positioned on the lateral wall of the left ventricle. Three types of activation maps were selected: (A) with functional block of an activation front; (B) with epicardial breakthrough; and (C) with a single broad wavefront without block lines.

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Because of its electrophysiological effects, hypothermia can influence the mechanisms that intervene in the sustaining of ventricular fibrillation. We hypothesized that a rapid and profound reduction of myocardial temperature impedes the maintenance of ventricular fibrillation, leading to termination of the arrhythmia. High-resolution epicardial mapping (series 1; n = 11) and transmural recordings of ventricular activation (series 2; n = 10) were used to analyze ventricular fibrillation modification during rapid myocardial cooling in Langendorff-perfused rabbit hearts.

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Introduction And Objectives: The aim of this study was to analyze the effects of myocardial stretching on excitation frequencies, as determined by spectral analysis, during ventricular fibrillation.

Methods: In 12 isolated rabbit heart preparations, ventricular activation during ventricular fibrillation was recorded with multiple electrodes. Recordings were obtained before, during and after ventricular dilatation produced with an intraventricular balloon.

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