52 research outputs found

    A new integrated approach to cardiac mechanics: reference values for normal left ventricle

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    The association between left ventricular (LV) myocardial deformation and hemodynamic forces is still mostly unexplored. The normative values and the effects of demographic and technical factors on hemodynamic forces are not known. The authors studied the association between LV myocardial deformation and hemodynamic forces in a large cohort of healthy volunteers. One-hundred seventy-six consecutive subjects (age range, 16\u201382; 51% women), with no cardiovascular risk factors or any relevant diseases, were enrolled. All subjects underwent an echo-Doppler examination. Both 2D global myocardial and endocardial longitudinal strain (GLS), circumferential strain (GCS), and the hemodynamic forces were measured with new software that enabled to calculate all these values and parameters from the three apical views. Higher LV mass index and larger LV volumes were found in males compared to females (85 \ub1 17 vs 74 \ub1 15\ua0g/m2 and 127 \ub1 28 vs 85 \ub1 18\ua0ml, p < 0.0001 respectively) while no differences of the mean values of endocardial and myocardial GLS and of myocardial GCS were found (p = ns) and higher endocardial GCS in women ( 12\ua030.6 \ub1 4.2 vs 12\ua031.8 \ub1 3.7; p = 0.05). LV longitudinal force, LV systolic longitudinal force and LV impulse were higher in men (16.2 \ub1 5.3 vs 13.2 \ub1 3.6; 25.1 \ub1 7.9 vs 19.4 \ub1 5.6 and 20.4 \ub1 7 vs 16.6 \ub1 5.2, p < 0.0001, respectively). A weak but statistically significant decline with age (p < 0.0001) was also found for these force parameters. This new integrated approach could differentiate normality from pathology by providing average deformation values and hemodynamic forces parameters, differentiated by age and gender

    Protective continuous ventilation strategy during cardiopulmonary bypass in children undergoing surgery for congenital heart disease: a prospective study

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    OBJECTIVES: The aim of this study was to evaluate if a 'protective' (low-tidal/low-frequency) ventilation strategy can shorten the postoperative ventilation time and minimize acute lung injury in children with congenital heart disease (CHD) undergoing repair with cardiopulmonary bypass (CPB). METHODS: This is a single-centre prospective, interventional study, including children with CHD under the age of 5 years, undergoing open-heart surgery with a CPB &gt;60 min, in hypothermia, haemodynamically stable, and without evident genetic abnormalities. Assist-control ventilation (tidal volume of 4 ml/kg, 10 breaths/min, positive end-expiratory pressure 5 cmH2O and FiO2 0.21) was applied in a cohort of patients during CPB. We compared clinical outcomes and in fully ventilated versus non-ventilated (control) patients. Propensity score was used to weigh ventilated and control groups to correct for the effect of other confounding clinical variables. Clinical and ventilation parameters and lung inflammatory biomarkers in tracheal aspirates were measured. The primary outcome was the postoperative intubation time of more or less than 48 h. RESULTS: We included 140 children (53 ventilated, 87 non-ventilated) with different CHD. There were no deaths or adverse events in ventilated patients. Using a weighted generalized linear model, we found no sufficient evidence for an effect of intraoperative ventilation on postoperative intubation time [estimate 0.13 (95% confidence interval, -0.08; 0.35), P = 0.22]. CONCLUSIONS: Continuous low-tidal/low-frequency mechanical ventilation during CPB is safe and harmless. However, no significant advantages were found when compared to non-ventilated patients in terms of postoperative ventilation time

    CHA2DS2-VASc Score Predicts Adverse Outcome in Patients with Simple Congenital Heart Disease Regardless of Cardiac Rhythm

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    Adult patients with simple congenital heart disease (sACHD) represent an expanding population vulnerable to atrial arrhythmias (AA). CHA2DS2-VASc score estimates thromboembolic risk in non-valvular atrial fibrillation patients. We investigated the prognostic role of CHA2DS2-VASc score in a non-selected sACHD population regardless of cardiac rhythm. Between November 2009 and June 2018, 427 sACHD patients (377 in sinus rhythm, 50 in AA) were consecutively referred to our ACHD service. Cardiovascular hospitalization and/or all-cause death were considered as composite primary end-point. Patients were divided into group A with CHA2DS2-VASc score = 0 or 1 point, and group B with a score greater than 1 point. Group B included 197 patients (46%) who were older with larger prevalence of cardiovascular risk factors than group A. During a mean follow-up of 70\ua0months (IQR 40\u201393), primary end-point occurred in 94 patients (22%): 72 (37%) in group B and 22 (10%, p < 0.001) in group A. Rate of death for all causes was also significantly higher in the group B than A (22% vs 2%, respectively, p < 0.001). Multivariable Cox regression analysis revealed that CHA2DS2-VASc score was independently related to the primary end-point (HR 1.84 [1.22\u20132.77], p = 0.004) together with retrospective AA, stroke/TIA/peripheral thromboembolism and diabetes. Furthermore, CHA2DS2-VASc score independently predicted primary end-point in the large subgroup of 377 patients with sinus rhythm (HR 2.79 [1.54\u20135.07], p = 0.01). In conclusion, CHA2DS2-VASc score accurately stratifies sACHD patients with different risk for adverse clinical events in the long term regardless of cardiac rhythm

    On the relationship between residual zonal flows and bump-on tail saturated instabilities

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    A connection is established between two classical problems: the non linear saturation of a bump-on tail instability in collisionless regime, and the decay of a zonal flow towards a finite amplitude residual. Reasons for this connection are given and commented

    Curso de formação de agentes de qualidade de água.

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    A qualidade da água; A água no nosso ambiente; Qual é a importância da água na vida de cada um?; Impactos aos recursos hídricos e causas de desperdícios; Doenças veiculadas pela água; Como avaliarmos a qualidade de nossa água?; Técnicas para tratamento da água; Lavagem e desinfeccão de caixas d'água; Desinfeccão de reservatórios diversos; Clorador por difusão; Fervura e Filtragem.bitstream/item/36204/1/Doc110.pd
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