Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Acta Chir Belg ; 124(2): 153-155, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37219416

RESUMEN

BACKGROUND: Transdiaphragmatic intrapericardial herniation (DIPH) of intra-abdominal organs is a rare but potentially life-threatening phenomenon often requiring urgent repair. There are currently no guidelines on the preferred repair technique in this situation. METHODS: Retrospective case report with long-term follow-up. We describe a case in which the left liver herniated into the pericardium after coronary artery bypass grafting (CABG) using the right gastroepiploic artery (RGEA). RESULTS: Urgent laparoscopic reduction of the liver herniation and repair of the large diaphragmatic defect was performed using an expanded polytetrafluoroethylene (ePTFE) mesh in a 50 year old male patient. Hemodynamic instability normalized after the hernia reduction. The postoperative course was uneventful. CT-scan evaluation after 9 and 20 years of follow-up showed perfect integrity of the mesh. CONCLUSION: A laparoscopic approach for DIPH is feasible in emergency situations provided sufficient hemodynamic stability of the patient. On-lay ePTFE mesh repair is a valid option for such repairs. We illustrate the long-term durability and safety of ePTFE for DIPH repair in what seems to be by far the longest documented follow-up after laparoscopic ePTFE mesh repair for DIPH.


Asunto(s)
Hernia Ventral , Laparoscopía , Masculino , Humanos , Persona de Mediana Edad , Estudios de Seguimiento , Estudios Retrospectivos , Puente de Arteria Coronaria/efectos adversos , Hernia Ventral/cirugía , Hígado , Mallas Quirúrgicas
2.
Pediatr Pulmonol ; 57(1): 245-252, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34559458

RESUMEN

OBJECTIVE: Description of the use of corticosteroids for the management of parapneumonic pleural effusion in children. METHODS: Retrospective single-center observational study of all children hospitalized with a diagnosis of parapneumonic pleural effusion during a 15-year period. RESULTS: We documented 97 cases of parapneumonic effusion during the study period, with a median age (interquartile range [IQR]) of 43 (33-61) months. Most of the children benefited from an evacuation of the pleural effusion (89/97, 91.8%): 21 patients (21.6%) were treated with needle thoracocentesis only, while a chest tube was inserted in 68 children (70.1%). Thirty-two patients (33%) were treated with intrapleural fibrinolysis. Fifty-five children (56.7%) received corticosteroids for persistent fever. The median time (IQR) between hospital admission and initiation of corticosteroids was 5.5 (4-7) days. When corticosteroids were initiated, children had been febrile for 9 (IQR: 8-11) days. The fever ceased in a median (IQR) of 0 (0-1) day after corticosteroids initiation. Only one patient required a video-assisted thoracoscopy that was necessary for morphological reasons (morbid obesity). No children treated with corticosteroids required surgery. All children were discharged from hospital. The median (IQR) hospital length of stay was 11 (8-14) days, with no difference between children with and those without corticosteroids. CONCLUSION: Our findings indicate that corticosteroids may be a part of the therapeutic armamentarium for children with parapneumonic effusion when conventional nonsurgical management fails.


Asunto(s)
Empiema Pleural , Derrame Pleural , Corticoesteroides/uso terapéutico , Tubos Torácicos , Niño , Preescolar , Empiema Pleural/complicaciones , Empiema Pleural/tratamiento farmacológico , Humanos , Derrame Pleural/tratamiento farmacológico , Estudios Retrospectivos
3.
Pediatr Emerg Care ; 38(2): e451-e457, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34009900

RESUMEN

OBJECTIVES: This study aimed to evaluate the impact of adding video conferencing to dispatcher-assisted telephone cardiopulmonary resuscitation (CPR) on pediatric bystander CPR quality. METHODS: We conducted a prospective, randomized manikin study among volunteers with no CPR training and among bachelor nurses. Volunteers randomly received either video or audio assistance in a 6-minute pediatric cardiac arrest scenario. The main outcome measures were the results of the Cardiff Test to assess compression and ventilation performance. RESULTS: Of 255 candidates assessed for eligibility, 120 subjects were randomly assigned to 1 of the 4 following groups: untrained telephone-guided (U-T; n = 30) or video-guided (U-V; n = 30) groups and trained telephone-guided (T-T; n = 30) or video-guided (T-V; n = 30) groups. Cardiac arrest was appropriately identified in 86.7% of the U-T group and in 100% in the other groups (P = 0.0061). Hand positioning was adequate in 76.7% of T-T, 80% of T-V, and 60% of U-V, as compared with 23.4% of the U-T group (P = 0.0001). Fewer volunteers managed to deliver 2 rescue breaths/cycle (P = 0.0001) in the U-T (16.7%) compared with the U-V (43.3%), the T-T (56.7%), and the T-V groups (60%).Subjects in the video groups had a lower fraction of minute to ventilate as compared with the telephone groups (P = 0.0005). CONCLUSIONS: In dispatcher-instructed children CPR simulation, using video assistance improves cardiac arrest recognition and CPR quality with more appropriate chest compression technique and ventilation delivering. The long interruptions in chest compression combined with the mixed success rate to deliver proper ventilation raise question about ventilation quality and its effectiveness.


Asunto(s)
Reanimación Cardiopulmonar , Paro Cardíaco Extrahospitalario , Niño , Humanos , Maniquíes , Paro Cardíaco Extrahospitalario/terapia , Estudios Prospectivos , Teléfono
4.
Pediatr Crit Care Med ; 21(6): e342-e353, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32217901

RESUMEN

OBJECTIVE: To describe the management of anemia at PICU discharge by pediatric intensivists. DESIGN: Self-administered, online, scenario-based survey. SETTING: PICUs in Australia/New Zealand, Europe, and North America. SUBJECTS: Pediatric intensivists. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Respondents were asked to report their decisions regarding RBC transfusions, iron, and erythropoietin prescription to children ready to be discharged from PICU, who had been admitted for hemorrhagic shock, cardiac surgery, craniofacial surgery, and polytrauma. Clinical and biological variables were altered separately in order to assess their effect on the management of anemia. Two-hundred seventeen responses were analyzed. They reported that the mean (± SEM) transfusion threshold was a hemoglobin level of 6.9 ± 0.09 g/dL after hemorrhagic shock, 7.6 ± 0.10 g/dL after cardiac surgery, 7.0 ± 0.10 g/dL after craniofacial surgery, and 7.0 ± 0.10 g/dL after polytrauma (p < 0.001). The most important increase in transfusion threshold was observed in the presence of a cyanotic heart disease (mean increase ranging from 1.80 to 2.30 g/dL when compared with baseline scenario) or left ventricular dysfunction (mean increase, 1.41-2.15 g/dL). One third of respondents stated that they would not prescribe iron at PICU discharge, regardless of the hemoglobin level or the baseline scenario. Most respondents (69.4-75.0%, depending on the scenario) did not prescribe erythropoietin. CONCLUSIONS: Pediatric intensivists state that they use restrictive transfusion strategies at PICU discharge similar to those they use during the acute phase of critical illness. Supplemental iron is less frequently prescribed than RBCs, and prescription of erythropoietin is uncommon. Optimal management of post-PICU anemia is currently unknown. Further studies are required to highlight the consequences of this anemia and to determine appropriate management.


Asunto(s)
Anemia , Alta del Paciente , Niño , Transfusión de Eritrocitos , Europa (Continente) , Hemoglobinas , Humanos , Unidades de Cuidado Intensivo Pediátrico , América del Norte , Encuestas y Cuestionarios
5.
Pediatr Emerg Care ; 33(10): 679-685, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28968304

RESUMEN

OBJECTIVE: Out-of-hospital cardiac arrest (OHCA) in pediatrics is a devastating event associated with poor survival rates. Although telephone dispatcher-assisted cardiopulmonary resuscitation (CPR; T-CPR) instructions improve the frequency and quality of bystander CPR for OHCA in adults, this support remains undeveloped in children. Our objective was to assess the effectiveness of a pediatric T-CPR protocol in untrained and trained bystanders. Secondarily, we sought to determine the feasibility and the effectiveness of ventilation in such a protocol. METHODS: Eligible adults with no CPR experience were recruited in a movie theater in Liege, as well as bachelor nursing students in Liege. All volunteers were randomly assigned either to T-CPR or to no-T-CPR using randomization. The volunteers were exposed to a pediatric manikin model cardiac arrest. On the basis of Cardiff evaluation test, data were collected to evaluate CPR performance. RESULTS: A total of 115 volunteers were assigned to 4 groups: untrained nonguided group (n = 27), untrained guided group (n = 32), trained nonguided group (n = 26), and trained guided group (n = 30). We found an improvement in CPR performance in the guided groups. Most volunteers (81.2%) in untrained guided group and 83.3% in the trained guided group were able to give 2 ventilations after each compressions cycle. CONCLUSIONS: In a pediatric manikin model of OHCA, T-CPR instructions including mouth-to-mouth ventilations and chest compressions produced a significant increase in resuscitation performance not only among previously untrained but also among trained volunteers.


Asunto(s)
Reanimación Cardiopulmonar/métodos , Competencia Clínica/estadística & datos numéricos , Sistemas de Comunicación entre Servicios de Urgencia , Paro Cardíaco Extrahospitalario/terapia , Adulto , Algoritmos , Bélgica , Femenino , Humanos , Lactante , Lenguaje , Masculino , Maniquíes , Estudios Prospectivos
6.
Ann Intensive Care ; 7(1): 107, 2017 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-29067568

RESUMEN

BACKGROUND: Anemia is prevalent at pediatric intensive care unit (PICU) admission and incident during PICU stay, but little is known about anemia at PICU discharge . Anemia after critical illness is an important issue because it could impact post-PICU outcome. We aimed to estimate the prevalence of anemia at PICU discharge and to determine its risk markers. METHODS: This is an ancillary study of a prospective observational study on transfusion practices conducted in the PICU of a tertiary care children's hospital. All children consecutively admitted to the PICU during a 1-year period were considered for inclusion. Data were prospectively collected from medical charts, except for hemoglobin (Hb) levels at PICU and hospital discharge that were collected retrospectively. Anemia was defined by an Hb concentration below the lower limit of the normal range for age. RESULTS: Among the 679 children retained for analysis, 390 (57.4%) were anemic at PICU discharge. After multivariate adjustment, anemia at PICU admission was the strongest risk marker of anemia at PICU discharge. The strength of this association varied according to age (interaction): The odds ratio (OR) (95% CI) of anemia at PICU discharge was 4.85 (1.67-14.11) for 1-5-month-old infants anemic versus not anemic at PICU admission, and it was 73.13 (13.43, 398.19) for adolescents anemic versus not anemic at PICU admission. Children admitted after a non-cardiac surgery had an increased risk of anemia at PICU discharge [OR 2.30 (1.37, 3.88), p = 0.002]. The proportion of anemic children differed between age categories, while the median Hb level did not exhibit significant variations according to age. CONCLUSIONS: Anemia is highly prevalent at PICU discharge and is strongly predicted by anemia at PICU admission. The usual age-based definitions of anemia may not be relevant for critically ill children. The consequences of anemia at PICU discharge are unknown and deserve further scrutiny.

7.
Eur J Pediatr ; 175(7): 921-30, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27075015

RESUMEN

UNLABELLED: This study aims to describe the pediatric physician-staffed EMS missions at a national level and to compare the pediatric and the adult EMS missions. Using a national database, we analyzed 254,812 interventions including 15,294 (6 %) pediatric emergencies. Less children than adults received an intravenous infusion (52.7 versus 77.1 %, p < 0.001), but the intra-osseous access was used more frequently in children (1.3 versus 0.8 %, p < 0.001). More children than adults benefited from a therapeutic immobilization (16.3 versus 13.2 %, p < 0.001). Endotracheal intubation was rare in children (2.1 %) as well as cardiopulmonary resuscitation (1.2 %). Children were more likely than adults to suffer from a neurological problem (32.4 versus 21.3 %, p < 0.001) or from a trauma (27.1 versus 16.8 %, p < 0.001). The prevalence of the pediatric diagnoses showed an age dependency: the respiratory problems were more prevalent in infants (40.3 % of the 0-12-months old), 52.1 % of the 1-4-year-old children suffered from a neurological problem, and the prevalence of trauma raised from 14.8 % of the infants to 47.1 % of the 11-15 year olds. CONCLUSION: Pre-hospital pediatric EMS missions are not frequent and differ from the adult interventions. The pediatric characteristics highlighted in this study should help EMS teams to be better prepared to deal with sick children in the pre-hospital setting. WHAT IS KNOWN: • Pediatric and adult emergencies differ. • Pediatric life-threatening emergencies are not frequent. What is New: • This study is the first to describe a European national cohort of pediatric physician-staffed EMS missions and to compare the pediatric and the adult missions at a national level. • This large cohort study confirms scarce regional data indicating that pediatric pre-hospital emergencies are not frequent and mostly non-life-threatening.


Asunto(s)
Servicios Médicos de Urgencia/estadística & datos numéricos , Tratamiento de Urgencia/estadística & datos numéricos , Adolescente , Adulto , Distribución por Edad , Anciano , Bélgica , Distribución de Chi-Cuadrado , Niño , Preescolar , Urgencias Médicas , Femenino , Humanos , Lactante , Recién Nacido , Infusiones Intravenosas/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
8.
Acta Paediatr ; 104(9): 861-71, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26033193

RESUMEN

UNLABELLED: Non-invasive ventilation (NIV) is commonly used in paediatric intensive care units (PICUs) for respiratory failure. This review aims to improve paediatricians' understanding of NIV, by specifying technical or practical considerations, giving advice about selecting patients and presenting pertinent published data about NIV in different circumstances. CONCLUSION: NIV is useful in PICUs if children are appropriately selected and carefully monitored. Technological advances and future clinical research will improve its use and success rate in PICU.


Asunto(s)
Cuidados Críticos , Ventilación no Invasiva , Selección de Paciente , Insuficiencia Respiratoria/terapia , Enfermedad Aguda , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Pediátrico , Monitoreo Fisiológico , Insuficiencia Respiratoria/diagnóstico , Insuficiencia Respiratoria/etiología , Resultado del Tratamiento
9.
Eur J Med Genet ; 57(5): 230-4, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24613577

RESUMEN

We report a 16-year-old girl with neonatal progeroid features and congenital lipodystrophy who was considered at birth as a possible variant of Wiedemann-Rautenstrauch syndrome. The emergence of additional clinical signs (marfanoid habitus, severe myopia and dilatation of the aortic bulb) lead to consider the diagnosis of the progeroid variant of Marfan syndrome. A de novo donor splice-site mutation (c.8226+1G>A) was identified in FBN1. We show that this mutation leads to exon 64 skipping and to the production of a stable mRNA that should allow synthesis of a truncated profibrillin-1, in which the C-terminal furin cleavage site is altered. FBN1 mutations associated with a similar phenotype have only been reported in four other patients. We confirm the correlation between marfanoid phenotype with congenital lipodystrophy and neonatal progeroid features (marfanoid-progeroid-lipodystrophy syndrome) and frameshift mutations at the 3' end of FBN1. This syndrome should be considered in differential diagnosis of neonatal progeroid syndromes.


Asunto(s)
Retardo del Crecimiento Fetal/diagnóstico , Lipodistrofia/diagnóstico , Síndrome de Marfan/diagnóstico , Proteínas de Microfilamentos/genética , Progeria/diagnóstico , Adolescente , Secuencia de Aminoácidos , Secuencia de Bases , Análisis Mutacional de ADN , Diagnóstico Diferencial , Femenino , Retardo del Crecimiento Fetal/genética , Fibrilina-1 , Fibrilinas , Humanos , Lipodistrofia/congénito , Lipodistrofia/genética , Síndrome de Marfan/genética , Técnicas de Diagnóstico Molecular , Datos de Secuencia Molecular , Progeria/genética
10.
Biomed Mater Eng ; 18(1 Suppl): S27-31, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18334721

RESUMEN

Intracoronary infusion of autologous bone marrow cells (CTX) has been shown to improve myocardial function in post infarct patients and in patients with chronic ischemic cardiomyopathy. Whether CTX affects exercise-induced changes in cardiac deformation and mitral regurgitation (MR) in patients with end stage heart failure has not been studied. In this small pilot study, eleven patients with chronic ischemic cardiomyopathy, ejection fraction (EF) <25%, no inducible ischemia and heart failure class NYHA III underwent CTX. Symptom-limited bicycle exercise echocardiography was performed pre- and 4 months post CTX and maximum systolic strain (msyepsilon), peak systolic strain rate (psysr) and effective regurgitant orifice of MR (ERO) were determined. There were no complications related to the procedure. The overall clinical benefit of CTX was limited with a trend towards improvement (NYHA 3.0+/-0.1 pre and 2.7+/-0.2 post CTX, p=0.06). The EF did not improve after CTX. The wall motion score index (WMSI) did not change at rest but decreased significantly during exercise (1.48+/-0.16 vs. 1.44+/-0.17, p=0.01). In conclusion, CTX may improve cardiac deformation and MR during exercise in patients with severe chronic heart failure when viable areas are targeted.


Asunto(s)
Trasplante de Médula Ósea/métodos , Cardiomiopatías/cirugía , Insuficiencia Cardíaca/cirugía , Isquemia Miocárdica/cirugía , Disfunción Ventricular Izquierda/cirugía , Cardiomiopatías/complicaciones , Cardiomiopatías/diagnóstico por imagen , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/etiología , Humanos , Luxemburgo , Masculino , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/diagnóstico por imagen , Proyectos Piloto , Resultado del Tratamiento , Ultrasonografía , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/diagnóstico por imagen
11.
J Card Fail ; 12(2): 108-13, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16520257

RESUMEN

BACKGROUND: Intracoronary infusion of autologous bone marrow cells (CTX) has been shown to improve myocardial function in postinfarct patients and in patients with chronic ischemic cardiomyopathy. Whether CTX affects exercise-induced changes in cardiac deformation and mitral regurgitation (MR) in patients with end-stage heart failure has not been studied. METHODS AND RESULTS: In this small pilot study, 11 patients with chronic ischemic cardiomyopathy, ejection fraction (EF) <25%, no inducible ischemia and heart failure class New York Heart Association (NYHA) III underwent CTX. Symptom-limited bicycle exercise echocardiography was performed pre- and 4 months post-CTX and maximum systolic strain (msyepsilon), peak systolic strain rate (psysr), and effective regurgitant orifice of MR (ERO) were determined. There were no complications related to the procedure. The overall clinical benefit of CTX was limited with a trend towards improvement (NYHA 3.0 +/- 0.1 pre- and 2.7 +/- 0.2 post-CTX, P = .06). The EF did not improve after CTX. The wall motion score index did not change at rest but decreased significantly during exercise (1.48 +/- 0.16 versus 1.44 +/- 0.17, P = .01). In patients with non-viable areas, msyepsilon, psysr, and ERO were not affected by CTX. However, in patients with viable areas, msyepsilon and psysr appeared to increase during exercise and ERO appeared to decrease from 19 +/- 5 to 16 +/- 5 mm(2). This effect was not apparent at rest and more pronounced with inferior viability. CONCLUSION: CTX may improve cardiac deformation and MR during exercise in patients with severe chronic heart failure when viable areas are targeted.


Asunto(s)
Trasplante de Médula Ósea , Isquemia Miocárdica/terapia , Ecocardiografía de Estrés , Femenino , Humanos , Infusiones Intraarteriales , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/fisiopatología , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/fisiopatología , Proyectos Piloto , Volumen Sistólico/fisiología , Sístole/fisiología , Trasplante Autólogo , Resultado del Tratamiento
12.
Inorg Chem ; 43(17): 5321-34, 2004 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-15310210

RESUMEN

The 1:1 reaction between the d(9)-d(9) Pd(2)(dmb)(2)Cl(2) complex (dmb = 1,8-diisocyano-p-menthane) and the diphosphine ligands (diphos) bis(diphenylphosphino)butane (5, dppb), bis(diphenylphosphino)pentane (6, dpppen), bis(diphenylphosphino)hexane (7, dpph), and bis(diphenylphosphino)acetylene (8, dpa) in the presence of LiClO(4) leads to the [[Pd(2)(dmb)(2)(diphos)](ClO(4))(2)](n) polymers. These new materials are characterized by NMR ((1)H, (13)C, (31)P), IR, Raman, and UV-vis spectroscopies (466 < lambda(max)(dsigma-dsigma*) < 480 nm), by ATG, XRD, and DSC methods, and by the capacity to make stand-alone films. From the measurements of the intrinsic viscosity in acetonitrile, the M(n) ranges from 16000 to 18400 (12 to 16 units). The dinuclear model complex [Pd(2)(dmb)(2)(PPh(3))(2)](ClO(4))(2) (4) is prepared and investigated as well. The molecular dynamic of the title polymers in acetonitrile solution is investigated by means of (13)C spin-lattice relaxation time (T(1)) and nuclear Overhauser enhancement methods (NOE). The number of units determined by T(1)/NOE methods is 3 to 4 times less than that found from the measurements of intrinsic viscosity, and is due to flexibility in the polymer backbone, even for bridging ligands containing only one (dmb) or two C-C single bonds (dpa). During the course of this study, the starting material Pd(2)(dmb)(2)Cl(2) was reinvestigated after evidence for oligomers in the MALDI-TOF spectrum was noticed. In solution, this d(9)-d(9) species is a binuclear complex (T(1)/NOE). This result suggests that the structure of the title polymers in solution and in the solid state may not be the same either. Finally, these polymers are strongly luminescent in PrCN glasses at 77 K, and the photophysical data (emission lifetimes, 1.50 < tau(e) < 2.75 ns; quantum yields, 0.026 < Phi(e) < 0.17) are presented. X-ray data for [Pd(2)(dppe)(2)(dmb)(2)](PF(6))(4): monoclinic, space group C2/c, a = 24.3735 A, b = 21.8576(13) A, c = 18.0034(9) A, b = 119.775(1) degrees, V = 8325.0(8) A(3), Z = 4.

13.
Inorg Chem ; 43(10): 3127-35, 2004 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-15132618

RESUMEN

The dimers [Cu(2)(dppm)(2)(CN-t-Bu)(3)](BF(4))(2) and [Ag(2)(dppm)(2)(CN-t-Bu)(2)](X)(2) (X(-) = BF(4)(-), ClO(4)(-)) and the coordination polymers [[M(diphos)(CN-t-Bu)(2)]BF(4)](n) (M = Cu, Ag; diphos = bis(diphenylphosphino)butane (dppb), bis(diphenylphosphino)pentane (dpppen), bis(diphenylphosphino)hexane (dpph)), [[Ag(2)(dppb)(3)(CN-t-Bu)(2)](BF(4))(2)](n), and [[Ag(dpppen)(CN-t-Bu)]BF(4)](n) have been synthesized and fully characterized as model materials for the mixed bridging ligand polymers which exhibit the general formula [[M(diphos)(dmb)]BF(4)](n) (M = Cu, Ag; dmb = 1,8-diisocyano-p-menthane) and [[Ag(dppm)(dmb)]ClO(4)](n). The identity of four polymers ([[Ag(dppb)(CN-t-Bu)(x)]BF(4)](n) (x = 1, 2), [[Ag(2)(dppb)(3)(CN-t-Bu)(2)](BF(4))(2)](n), [[Ag(dppm)(dmb)]ClO(4)](n)) and the two dimers has been confirmed by X-ray crystallography. The structure of [[Ag(dppm)(dmb)]ClO(4)](n) exhibits an unprecedented 1-D chain of the type "[Ag(dmb)(2)Ag(dppm)(2)(2+)](n)", where d(Ag(.)Ag) values between tetrahedral Ag atoms are 4.028(1) and 9.609(1) A for the dppm and dmb bridged units, respectively. The [[Ag(dppb)(CN-t-Bu)(x)]BF(4)](n) polymers (x = 1, 2) form zigzag chains in which the Ag atoms are tri- and tetracoordinated, respectively. The [[Ag(2)(dppb)(3)(CN-t-Bu)(2)](BF(4))(2)](n) polymer, which is produced from the rearrangement of [[Ag(dppb)(CN-t-Bu)(2)]BF(4)](n), forms a 2-D structure described as a "honeycomb" pattern, where large [Ag(dppb)(+)](6) macrocycles each hosting two counterions and two acetonitrile guest molecules are observed. Properties such as glass transition temperature, morphology, thermal decomposition, and luminescence in the solid state at 293 K are reported. The luminescence bands exhibit maxima between 475 and 500 nm with emission lifetimes ranging between 6 and 55 micros. These emissions are assigned to a metal-to-ligand charge transfer (MLCT) of the type M(I) --> pi(NC)/pi(PPh(2)).

14.
J Am Coll Cardiol ; 42(11): 1921-8, 2003 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-14662253

RESUMEN

OBJECTIVES: We sought to examine the determinants of exercise-induced changes in ischemic mitral regurgitation (MR) in patients with left ventricular (LV) dysfunction. BACKGROUND: In the post-myocardial infarction (MI) phase, ischemic MR contributes to worsening of symptoms and of LV dysfunction. METHODS: In this study, 70 patients in the chronic, post-MI phase, with LV ejection fraction <45% and at least mild MR, underwent semi-supine exercise Doppler echocardiography. The effective regurgitant orifice (ERO) of MR was quantified at rest and during exercise. Exercise-induced changes in ERO were compared with changes in mitral deformation and in local and global LV remodeling. RESULTS: The wide range of exercise-induced ERO changes that were observed was unrelated to the degree of MR at rest (r = 0.20). Effective regurgitant orifice changes correlated best with changes in mitral deformation (i.e., differences in systolic mitral tenting area, systolic annular area, and coaptation height) (p < 0.0001). Posterior displacement of the papillary muscles was associated with larger changes in the ERO in both infarct groups. In patients with inferior MI, a decrease in the ERO was related to improvement in wall motion (r = 0.68). The independent predictors of ERO changes during exercise were changes in systolic annular area for all infarct categories, in tenting area and wall motion score in the global population and those with inferior infarction, and in apical displacement of mitral leaflets for patients with anterior MI. CONCLUSIONS: The degree of MR at rest is unrelated to exercise-induced changes in EROs, which are related to those in local LV remodeling and in mitral deformation but not those in global LV function.


Asunto(s)
Ejercicio Físico/fisiología , Insuficiencia de la Válvula Mitral/fisiopatología , Infarto del Miocardio/complicaciones , Disfunción Ventricular Izquierda/complicaciones , Ecocardiografía Doppler , Humanos , Válvula Mitral/fisiopatología , Reproducibilidad de los Resultados , Remodelación Ventricular/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...