Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 65
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Support Care Cancer ; 26(2): 549-555, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28856448

RESUMEN

CONTEXT: There are no prospective pediatric trials evaluating olanzapine for chemotherapy-induced nausea and vomiting (CINV) prevention. OBJECTIVE: This study evaluated the feasibility of a trial of olanzapine to evaluate the contribution of olanzapine to CINV control in pediatric oncology patients. METHODS: Patients < 18 years receiving CINV prophylaxis with ondansetron/granisetron/palonosetron ± dexamethasone ± aprepitant were eligible to participate in this prospective, single-arm, open-label study. All patients received olanzapine (0.14 mg/kg/dose; max 10 mg/dose) once daily orally starting before the first chemotherapy dose and continuing for up to four doses after the last chemotherapy administration. A future trial was considered feasible if mean time to enroll 15 patients was ≤ 12 months/site, ≥ 12/15 took at least half of the planned olanzapine doses, and ≤ 3/15 experienced significant sedation or dizziness despite dose reduction. The proportion of children who experienced complete CINV control (no nausea, vomiting, or retching) was described. RESULTS: Fifteen patients (range 4.1-17.4 years) participated; mean recruitment period was 9.3 months/site. All patients took at least half of the planned olanzapine doses. Six patients experienced sedation which resolved with olanzapine dose reduction (N = 5) or bedtime administration (N = 1). Olanzapine was stopped in one patient with blurry vision and in another with increased plasma GGT values. In both the acute and delayed phases, eight patients experienced complete control of vomiting but almost all (14/15) had nausea. CONCLUSION: A pediatric trial of olanzapine for CINV control is feasible. Our findings will inform the design of a future study.


Asunto(s)
Antieméticos/uso terapéutico , Náusea/tratamiento farmacológico , Olanzapina/uso terapéutico , Vómitos/tratamiento farmacológico , Adolescente , Antieméticos/administración & dosificación , Antieméticos/farmacología , Niño , Preescolar , Estudios de Factibilidad , Femenino , Humanos , Masculino , Náusea/inducido químicamente , Olanzapina/administración & dosificación , Olanzapina/farmacología , Vómitos/inducido químicamente
2.
J Neurooncol ; 133(3): 581-587, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28508928

RESUMEN

Embryonal tumors are a heterogeneous group of central nervous system (CNS) tumors whose subgroups have varying incidence and outcome. Despite these differences, they are often grouped as a single entity for study purposes. To date, there are no Canadian multi-institutional studies examining the incidence and outcome of all embryonal subtypes. The current study is an observational study reviewing embryonal tumors in all patients less than 36 months of age diagnosed with a CNS tumor in Canada from 1990 to 2005. Embryonal tumors accounted for 26.9% of all CNS tumors. Medulloblastomas were the highest proportion of the embryonal tumors at 61.5%. Atypical teratoid/rhabdoid tumors (AT/RT) had the second highest proportion of embryonal tumors at 18%. The proportion of primitive neuroectodermal tumors (PNET) was 16%, with 2.6 and 1.9% for congenital medulloepithelioma and ependymoblastoma tumors, respectively. AT/RT and PNET were more common in younger age groups. Medulloblastoma became more prevalent with increasing age, with its highest prevalence in the 25 to 36 month age group. Survival rates for our Canadian population at 18 and 24 months were 0.74 and 0.68 for medulloblastoma, 0.64 and 0.60 for PNET, and 0.36 and 0.29 for AT/RT, respectively. Overall, our data are comparable with published international rates for embryonal tumors. These incidence and outcome figures can guide future research into these rare tumors.


Asunto(s)
Neoplasias del Sistema Nervioso Central/epidemiología , Neoplasias de Células Germinales y Embrionarias/epidemiología , Canadá/epidemiología , Neoplasias del Sistema Nervioso Central/terapia , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Neoplasias de Células Germinales y Embrionarias/terapia , Análisis de Supervivencia
3.
Br J Cancer ; 111(7): 1262-8, 2014 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-25101569

RESUMEN

BACKGROUND: Objective was to evaluate and refine a new instrument for paediatric cancer symptom screening named the Symptom Screening in Pediatrics Tool (SSPedi). METHODS: Respondents were children 8-18 years of age undergoing active cancer treatment and parents of eligible children. Respondents completed SSPedi once and then responded to semi-structured questions. They rated how easy or difficult SSPedi was to complete. For items containing two concepts, we asked respondents whether concepts should remain together or be separated into two questions. We also asked about each item's importance and whether items were missing. Cognitive probing was conducted in children to evaluate their understanding of items and the response scale. After each group of 10 children and 10 parents, responses were reviewed to determine whether modifications were required. Recruitment ceased with the first group of 10 children in which modifications were not required. RESULTS: Thirty children and 20 parents were required to achieve a final version of SSPedi. Fifteen items remain in the final version; the score ranges from 0 to 60. CONCLUSIONS: Using opinions of children with cancer and parents of paediatric cancer patients, we successfully developed a symptom screening tool that is easy to complete, is understandable and demonstrates content validity.


Asunto(s)
Antineoplásicos/efectos adversos , Neoplasias/tratamiento farmacológico , Autoinforme , Adolescente , Antineoplásicos/uso terapéutico , Ansiedad/inducido químicamente , Ansiedad/diagnóstico , Niño , Femenino , Humanos , Masculino , Náusea/inducido químicamente , Náusea/diagnóstico , Neoplasias/patología , Dolor/inducido químicamente , Dolor/diagnóstico
4.
Can J Neurol Sci ; 41(4): 442-7, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24878467

RESUMEN

BACKGROUND: Vinca alkaloids and platinum-containing chemotherapeutic drugs have the potential to cause chemotherapy-induced peripheral neuropathy (CIPN). This study determined the frequency of CIPN among children who were treated for acute lymphoblastic leukemia (ALL), lymphoma, brain tumour or Wilms tumour. PROCEDURE: This retrospective cohort study reviewed 252 patients treated at the Children's hospital of Eastern Ontario from 2001-2011. Patients were considered to have CIPN if they developed clinical symptoms of CIPN such as limb paraesthesia, weakness and/or ataxia during chemotherapy and their treating neurologist or oncologist deemed that their symptoms were due to a peripheral cause. Patients were excluded if their treatment regime did not include chemotherapy. RESULTS: The overall frequency of CIPN was 18.3% (46/252). Tumour-specific CIPN rates were: 18.9% (29/154) for ALL; 9.4% (3/32) for lymphoma; 17.9% (5/28) for Wilms tumour; and 23.7% (9/38) for brain tumour patients. Nerve conduction studies were completed for 17% of patients (all tumour types) and were abnormal in all but one patient. Among surviving CIPN patients (41/46), 93% showed no clinical deficits at their last examination, which was on average 56 months from time of diagnosis to last follow-up visit. CONCLUSIONS: The frequency of CIPN was less than that previously reported in adults receiving chemotherapy. Children with CIPN have a favourable outcome with most showing clinical improvement during the maintenance phase of treatment or after chemotherapy completion.


Asunto(s)
Antineoplásicos/efectos adversos , Oncología Médica , Neoplasias/tratamiento farmacológico , Enfermedades del Sistema Nervioso Periférico/inducido químicamente , Enfermedades del Sistema Nervioso Periférico/diagnóstico , Niño , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Neoplasias/epidemiología , Ontario/epidemiología , Enfermedades del Sistema Nervioso Periférico/epidemiología , Estudios Retrospectivos
5.
Ann Oncol ; 24(3): 801-6, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23108950

RESUMEN

BACKGROUND: The objective was to compare 5-year overall survival (OS) between adolescent and young adult (AYA) patients (age 15-19) with acute lymphoblastic leukemia (ALL) treated at a pediatric versus an adult center. PATIENTS AND METHODS: This was a population-based analysis using administrative data of Ontario ALL AYA patients diagnosed between 1986-2009. We calculated predicted survival proportions (PSPs) and 95% confidence intervals (CI). We also surveyed sites to determine whether pediatric or adult-based protocols were used in each period. RESULTS: Overall, 290 patients between 15-19 years of age were diagnosed with ALL during the study period; 144 patients (49.7%) were treated at an adult center. When adjusted for gender, age, income quintile and time period, AYA patients treated at a pediatric center did not have a significantly different PSP (0.65, 95% CI: 0.56-0.75) in comparison to those treated at an adult center (0.62, 95% CI 0.52-0.73; P = 0.87). Most AYA patients treated at adult centers received pediatric protocols in the recent periods. CONCLUSIONS: Using population-based data, AYA ALL patients had similar outcomes whether treated at a pediatric or an adult center. Early introduction of aggressive treatment protocols in adult centers may have negated differences in outcomes among AYA patients by site of care.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Instituciones Oncológicas , Femenino , Hospitales Pediátricos , Humanos , Estimación de Kaplan-Meier , Masculino , Ontario/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Modelos de Riesgos Proporcionales , Resultado del Tratamiento , Adulto Joven
7.
Mycoses ; 56(4): 482-7, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23437849

RESUMEN

Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in paediatric acute myeloid leukaemia (AML). This study describes risk factors for IFI and IFI-related sepsis in this population. We conducted a population-based, retrospective cohort study of children with AML in Canada. IFIs during chemotherapy and prior to haematopoietic stem cell transplantation, relapse, persistent disease or death were identified. Risk factors for proven or probable IFI were examined. Among courses complicated by IFI, risk factors for sepsis were also evaluated. There were 341 children with AML included of which 41 (12.0%) experienced 46 different episodes of IFI. Candida species accounted for 23 (50.0%) of IFIs and Aspergillus spp. accounted for 14 (30.4%). Days of broad-spectrum antibiotics, days of corticosteroids and neutropenia at start of the course were independently associated with IFI. Only days of fever were independently associated with IFI-related sepsis. Invasive fungal infections occurred in 12.0% of paediatric AML patients. Risk factors for IFI and IFI-related sepsis were identified. This knowledge may help to consider targeted strategies.


Asunto(s)
Fungemia/epidemiología , Fungemia/microbiología , Huésped Inmunocomprometido , Leucemia Mieloide Aguda/complicaciones , Infecciones Oportunistas/epidemiología , Infecciones Oportunistas/microbiología , Adolescente , Canadá/epidemiología , Niño , Preescolar , Estudios de Cohortes , Femenino , Hongos/clasificación , Hongos/aislamiento & purificación , Humanos , Lactante , Leucemia Mieloide Aguda/tratamiento farmacológico , Masculino , Prevalencia , Estudios Retrospectivos , Factores de Riesgo
8.
Clin Obes ; 8(1): 55-67, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29024558

RESUMEN

Survivors of childhood brain tumours (SCBT) have increased cardiometabolic risks, but the determinants of these risks are unclear. This systematic review aims to compare the prevalence of overweight and obesity as well as adiposity measures between SCBT and non-cancer controls. The PubMed, EMBASE, MEDLINE, CINAHL and the Cochrane Library databases were searched. The primary outcomes were the prevalence of overweight and obesity based on body mass index. The secondary outcomes were adiposity measures including percent fat mass, waist-to-hip and waist-to-height ratios. Forty-one studies were included in the meta-analysis. The prevalence of overweight and obesity combined was similar between overall SCBT, SCBT excluding craniopharyngioma and non-cancer controls (42.6%, 95% CI 30.1-55.1 vs. 31.7%, 95% CI 20.4-43.0 vs. 40.4%, 95% CI 34.0-46.8). We also found that SCBT have higher percent fat mass (mean difference 4.1%, 95% CI 2.0-6.1), waist-to-hip ratio (mean difference 0.07, 95% CI 0.02-0.13) and waist-to-height ratio (mean difference 0.06, 95% CI 0.01-0.10) than non-cancer controls. We conclude that SCBT have similar overweight and obesity distribution but higher adiposity than non-cancer controls. More studies were needed to explore the determinants of adiposity and its contribution to cardiometabolic outcomes in SCBT.


Asunto(s)
Adiposidad , Neoplasias Encefálicas/terapia , Supervivientes de Cáncer , Sobrepeso/epidemiología , Obesidad Infantil/epidemiología , Adolescente , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/epidemiología , Distribución de Chi-Cuadrado , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Oportunidad Relativa , Sobrepeso/diagnóstico , Sobrepeso/fisiopatología , Obesidad Infantil/diagnóstico , Obesidad Infantil/fisiopatología , Prevalencia , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
9.
Obes Rev ; 18(8): 899-914, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28544764

RESUMEN

BACKGROUND: Survivors of childhood brain tumours (SCBT) are at risk of type 2 diabetes and cardiovascular diseases. Obesity is a major driver of cardiometabolic diseases in the general population, and interventions that tackle obesity may lower the risk of these chronic diseases. The goal of this systematic review was to summarize current evidence for the presence of interventions to manage obesity, including hypothalamic obesity, in SCBT. METHODS: The primary outcome of this review was the body mass index z-score change from baseline to the end of the intervention and/or follow-up. Literature searches were conducted in PsycINFO, CINAHL, the Cochrane Library, Medline, SPORTDiscus, EMBASE and PubMed. Two reviewers completed study evaluations independently. RESULTS: Eleven publications were included in this systematic review (lifestyle intervention n = 2, pharmacotherapy n = 6 and bariatric surgery n = 3). While some studies demonstrated effectiveness of interventions to manage obesity in SCBT and alter markers of obesity and cardiometabolic risk, the evidence base was limited and of low quality, and studies focused on hypothalamic obesity. We conclude that there is urgent need to conduct adequately powered trials of sufficient duration, using existing and novel therapies to manage obesity, reduce the burden of cardiometabolic disorders and improve outcomes in SCBT.


Asunto(s)
Fármacos Antiobesidad/uso terapéutico , Cirugía Bariátrica , Neoplasias Encefálicas/complicaciones , Enfermedades Hipotalámicas/terapia , Estilo de Vida , Obesidad/terapia , Dieta Reductora , Humanos , Enfermedades Hipotalámicas/tratamiento farmacológico , Enfermedades Hipotalámicas/etiología , Enfermedades Hipotalámicas/cirugía , Obesidad/tratamiento farmacológico , Obesidad/etiología , Obesidad/cirugía , Resultado del Tratamiento
10.
Clin Microbiol Infect ; 22(6): 563.e9-563.e17, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26932518

RESUMEN

We evaluated single nucleotide polymorphisms (SNPs) associated with infection risk in children with newly diagnosed acute myeloid leukaemia (AML). We conducted a multicentre, prospective cohort study that included children aged ≤18 years with de novo AML. DNA was isolated from blood lymphocytes or buccal swabs, and candidate gene SNP analysis was conducted. Primary outcome was the occurrence of microbiologically documented sterile site infection during chemotherapy. Secondary outcomes were Gram-positive and -negative infections, viridans group streptococcal infection and proven/probable invasive fungal infection. Interpretation was guided by consistency in risk alleles and microbiologic agent with previous literature. Over the study period 254 children and adolescents with AML were enrolled. Overall, 190 (74.8%) had at least one sterile site microbiologically documented infection. Among the 172 with inferred European ancestry and DNA available, nine significant associations were observed; two were consistent with previous literature. Allele A at IL1B (rs16944) was associated with decreased microbiologically documented infection, and allele G at IL10 (rs1800896) was associated with increased risk of Gram-positive infection. We identified SNPs associated with infection risk in paediatric AML. Genotype may provide insight into mechanisms of infection risk that could be used for supportive-care novel treatments.


Asunto(s)
Enfermedades Transmisibles/epidemiología , Enfermedades Transmisibles/genética , Predisposición Genética a la Enfermedad , Interleucina-1beta/genética , Leucemia Mieloide Aguda/complicaciones , Polimorfismo de Nucleótido Simple , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Estudios Prospectivos , Medición de Riesgo
11.
J Am Coll Cardiol ; 11(1): 133-8, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2961793

RESUMEN

Balloon dilation is effective in the immediate relief of obstruction due to unoperated coarctation of the aorta. However, the long-term benefits and complications of this procedure have not been established. Thirty-three patients underwent balloon dilation of unoperated coarctation using a percutaneous technique from November 1983 to December 1985. High quality biplane angiography was performed before and after dilation. Follow-up was obtained in 20 patients from 6 to 31 months following dilation. Angiography was performed at follow-up in 10, nuclear magnetic resonance (NMR) imaging in 10 and both NMR imaging and angiography in 3. Balloon dilation was successful in 31 of the 33 patients with a decrease in average systolic pressure gradient from 46 to 8 mm Hg. There was no significant change in gradient on follow-up physical examination and at recatheterization in 10 patients. In addition, there was no evidence of restenosis on follow-up angiography and NMR imaging. In two patients, a small aneurysm formed at the site of balloon dilation. Balloon dilation of unoperated coarctation is effective, providing lasting relief of coarctation gradient and no evidence of restenosis. However, because of the uncertain natural history of aneurysms after dilation, this procedure should be considered investigational until further follow-up on patients with and without an aneurysm is available.


Asunto(s)
Angioplastia de Balón , Coartación Aórtica/terapia , Angiografía , Aorta Torácica/patología , Coartación Aórtica/complicaciones , Presión Sanguínea , Niño , Angiografía Coronaria , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Recurrencia , Factores de Tiempo
12.
J Am Coll Cardiol ; 11(5): 970-6, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-2965717

RESUMEN

The clinical significance of myocardial perfusion defects present early after angiographically successful percutaneous transluminal coronary angioplasty was assessed in 53 patients using thallium-201 single photon emission computed tomography combined with pharmacologic vasodilation induced by a large dose (300 mg) of orally administered dipyridamole. Myocardial tomographic images were obtained at a mean of 20 +/- 6 h (SD) before and 2.9 +/- 2.7 days after angioplasty. Before angioplasty, 15 (28%) of the 53 patients developed angina after dipyridamole administration, in contrast to only 3 (7.5%) of 40 patients after angioplasty (p less than 0.001). The mean percent luminal area stenosis decreased from 93 +/- 6% before angioplasty to 34 +/- 17% after angioplasty (p less than 0.001). Myocardial perfusion defects, present in 49 (93%) of the 53 patients before angioplasty, were reversible in 44 patients (83%), all of whom underwent dilation of arteries supplying the ischemic areas. After angioplasty, 26 (65%) of 40 patients had no ischemic defects, whereas 14 (35%) of the patients still had an ischemic defect in the vascular territory of the dilated artery. After a mean follow-up period of 21.7 months, 13 (33%) of 39 patients developed restenosis, 10 of whom had an ischemic defect early after angioplasty. Restenosis developed in 10 (71%) of 14 patients with an ischemic defect after angioplasty, but in only 3 (11.5%) of the patients without an ischemic defect (p = 0.007). In conclusion, thallium-201 tomography after oral dipyridamole affords convenient assessment of the physiologic significance of coronary stenosis present before angioplasty and the residual stenosis after angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Angioplastia de Balón , Circulación Coronaria/efectos de los fármacos , Enfermedad Coronaria/terapia , Dipiridamol/administración & dosificación , Radioisótopos de Talio , Tomografía Computarizada de Emisión/métodos , Administración Oral , Adulto , Anciano , Angina de Pecho/inducido químicamente , Color , Enfermedad Coronaria/diagnóstico por imagen , Dipiridamol/efectos adversos , Dipiridamol/farmacología , Tolerancia a Medicamentos , Femenino , Estudios de Seguimiento , Hemodinámica/efectos de los fármacos , Humanos , Interpretación de Imagen Asistida por Computador , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Recurrencia , Radioisótopos de Talio/administración & dosificación , Factores de Tiempo , Vasodilatación
13.
J Am Coll Cardiol ; 9(1): 127-35, 1987 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3794090

RESUMEN

To assess the potential of in vivo nuclear magnetic resonance imaging for the detection of reperfused myocardium, in vivo T2-weighted spin echo images were obtained of dogs at 0.15 tesla. Imaging was done during 3 hours of coronary occlusion (group I), and during 3 hours of coronary occlusion followed by 1 hour of reperfusion (group II). On sacrifice, the hearts were drained of blood and imaged in situ to determine the effect of in vivo imaging on myocardial signal intensity. The hearts were then excised and imaged at 1.4 tesla to compare the effect of high resolution imaging on image quality. Of the six hearts in group I and the eight hearts in group II with a myocardial infarction and suitable image quality, four of the former hearts and six of the latter demonstrated a small but visible increase in infarct signal intensity at 3 hours of occlusion on the time to echo [TE] = 60 ms, single echo images. The T2 (transverse) relaxation time of the infarct (measured in vitro by spectrometer) increased by 13% when compared with normal tissue. In contrast, the reperfused infarct was more easily visualized, with signal intensity increasing by 31 +/- 17% and infarct T2 increasing by 20%. Imaged at 1.4 tesla, the excised hearts showed the infarct to be subendocardial during occlusion and extending transmurally with reperfusion. It is concluded that, although visualized, the increase in infarct signal intensity at 3 hours of coronary occlusion is small and this is consistent with the small increase in infarct signal intensity and T2 relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Espectroscopía de Resonancia Magnética , Infarto del Miocardio/diagnóstico , Miocardio/patología , Animales , Circulación Coronaria , Perros
14.
Am J Med ; 87(1): 40-7, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2741980

RESUMEN

PURPOSE: The ability of stored intracellular iron to enhance magnetic susceptibility forms the basis by which tissue iron can be detected by nuclear magnetic resonance (NMR) imaging. We used this technique to assess myocardial, spleen, and liver iron content in patients with known or suspected iron overload disorders. PATIENTS AND METHODS: Spin echo NMR images were obtained in 30 patients; 20 had chronic anemias treated by multiple blood transfusions, five had idiopathic hemochromatosis, and five had non-hemochromatotic liver disease with elevated serum ferritin levels and no stainable iron on liver biopsy. The acquisition of oblique images through the short axis of the left ventricle permitted assessment of left ventricular function, while demonstrating the liver and spleen on the same image. Iron content was assessed using a signal intensity ratio of organ (spleen, liver, or myocardium) to skeletal muscle. RESULTS: In patients with multiple blood transfusions, iron content was highest in liver, followed by the spleen. Significant iron overload was detected in the myocardium of only one patient. Left ventricular systolic wall thickening was normal in patients receiving multiple blood transfusions. Two patients with treated idiopathic hemochromatosis had normal signal intensity ratios, and three untreated patients had evidence of significant deposits of iron in the liver and spleen as indicated by a reduction in signal intensity ratios (0.2 +/- 0.01 and 0.9 +/- 0.01, respectively). Five patients with non-hemochromatotic liver disease and high serum ferritin levels had normal signal intensity ratios by NMR imaging. CONCLUSION: NMR imaging is a useful method of detecting tissue iron and distinguishing disease due to iron overload. Myocardial iron deposition is a late event, occurring after accumulation of iron in the spleen and liver.


Asunto(s)
Hierro/análisis , Hígado/análisis , Imagen por Resonancia Magnética , Miocardio/análisis , Bazo/análisis , Adulto , Transfusión Sanguínea , Femenino , Ferritinas/sangre , Corazón/fisiopatología , Hemocromatosis/diagnóstico , Humanos , Hierro/envenenamiento , Hígado/patología , Masculino , Persona de Mediana Edad , Miocardio/patología , Bazo/patología
15.
J Nucl Med ; 28(5): 871-7, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-3572546

RESUMEN

To establish the effect of the paramagnetic contrast agent gadolinium diethylenetriaminepentaacetic acid ([Gd]DTPA) on myocardial magnetic resonance relaxation parameters T1 and T2, and its relationship to myocardial perfusion, we administered [Gd] DTPA 0.2 mM/kg to two groups of dogs. Group I had severe, resting myocardial ischemia induced by coronary occlusion, followed in 2 min by [Gd]DTPA infusion and heart excision 1 min later. Group II had a variable reduction in blood flow. In Group II the coronary vasodilator dipyridamole was infused to enhance blood flow to the normal myocardium before [Gd]DTPA was given. In Group I [Gd]DTPA caused a significant difference in T1 between the normal and severely ischemic zones; changes in T1 correlated with the severity of myocardial ischemia. Although vasodilatation delivered more Gd-DTPA to the normal myocardium in Group II, the lack of further decrease in T1 suggested that it was cleared more rapidly. Thus, [Gd]DTPA permits the detection and characterization of severe, resting myocardial ischemia by magnetic resonance techniques. Using the experimental techniques described in this study, less severe flow differences caused by vasodilatation and resultant hyperemia are not detected.


Asunto(s)
Medios de Contraste , Enfermedad Coronaria/diagnóstico , Gadolinio , Espectroscopía de Resonancia Magnética , Compuestos Organometálicos , Ácido Pentético , Animales , Circulación Coronaria/efectos de los fármacos , Dipiridamol , Perros , Gadolinio DTPA
16.
Am J Cardiol ; 55(6): 680-7, 1985 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-3883739

RESUMEN

The clinical and hemodynamic effects of propranolol, propranolol-verapamil (P-V), propranolol-nifedipine (P-N) and propranolol-diltiazem (P-D) were studied in 19 patients with chronic exertional angina pectoris. A placebo-controlled, double-blind, randomized, crossover study design was used in which patients took each treatment for a 4-week period. The 3 combinations equally reduced the incidence of angina attacks and decreased ST-segment depression. Left ventricular hypokinesia during exercise was lessened and end-systolic volume during exercise decreased with all combinations. Because of a corresponding reduction of normokinetic segmental function, global ejection fraction during exercise remained unchanged. Heart size increased (p less than 0.05) and the PR interval lengthened (p less than 0.001) with P-V and P-D compared to P-N. The largest number of adverse clinical reactions occurred with P-V, whereas the fewest occurred with P-D. Almost all patients preferred combined therapy over propranolol and many favored 1 combination over the others. In summary, when therapy with combined beta- and calcium channel-blocking drugs is planned, P-D should be considered the combination of first choice because of its low incidence of adverse clinical effects. In the presence of possible or definite abnormalities of atrioventricular nodal conduction or decreased left ventricular function, P-N should be considered. Although P-V is associated with frequent adverse reactions, a trial may be warranted if the other combinations are unsuccessful.


Asunto(s)
Angina de Pecho/tratamiento farmacológico , Bloqueadores de los Canales de Calcio/uso terapéutico , Hemodinámica/efectos de los fármacos , Propranolol/uso terapéutico , Adulto , Anciano , Angina de Pecho/etiología , Angina de Pecho/fisiopatología , Ensayos Clínicos como Asunto , Diltiazem/uso terapéutico , Método Doble Ciego , Quimioterapia Combinada/efectos adversos , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nifedipino/uso terapéutico , Placebos , Propranolol/efectos adversos , Distribución Aleatoria , Verapamilo/uso terapéutico
17.
Am J Cardiol ; 69(16): 1291-5, 1992 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-1585862

RESUMEN

The T2-weighted spin-echo technique is currently the most frequently used magnetic resonance imaging (MRI) method to visualize acute myocardial infarction. However, image quality is often degraded by ghost artifacts from blood flow, and respiratory and cardiac contractile motion. To enhance the usefulness of this technique for detailed characterization of infarction, a velocity-compensated spin-echo pulse sequence was tested by imaging a flow phantom, 6 normal subjects and 17 patients with acute myocardial infarction. After preliminary studies were performed in 7 patients to determine optimal imaging parameters, a standardized imaging protocol was used in the next 10. The location of myocardial infarction identified by the electrocardiogram and coronary anatomy was correctly identified in 10 of 10 patients. Distribution of the injury within the left ventricle was clearly visualized, and showed that patients often had a mixture of transmural and nontransmural injury. Heterogenous distribution of signal intensity within the infarction suggested the presence of hemorrhage. Papillary muscle involvement was readily apparent. Signal intensity of the infarction (brightest segment) was increased by 89 +/- 31% compared with the mean of the remote segments. The myocardial/skeletal muscle ratio was significantly (p less than 0.001) increased for the infarction segments compared with that for remote myocardium, allowing quantitative analysis of segmental signal intensity. The MRI wall motion study obtained as part of this protocol demonstrated wall thickening in 58% of the infarction segments and in 6 of 10 patients. This finding suggested the presence of reversibly injured myocardium. In conclusion, the results demonstrate the potential of MRI for detailed tissue characterization after acute myocardial infarction.


Asunto(s)
Infarto del Miocardio/diagnóstico , Adulto , Anciano , Angioplastia Coronaria con Balón , Circulación Coronaria , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Modelos Estructurales , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/terapia , Terapia Trombolítica
18.
Am J Cardiol ; 64(16): 1002-9, 1989 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-2816729

RESUMEN

Nuclear magnetic resonance (NMR) imaging clearly delineates cardiovascular structures without interference from overlying bone and lung tissue. The techniques of NMR imaging and echocardiography were compared in 26 patients with pericardial effusions, 10 of whom had associated pleural effusions. In those patients with fluid detected by both techniques, estimated size of the effusion tended to be somewhat larger by NMR. NMR imaging detected several small pericardial effusions that were not visualized by echocardiography. Both techniques demonstrated loculation well, although NMR imaging was better for detecting fluid located superiorly at the aortic pericardial reflection site, medially at the border of the right atrium and posteriorly at the left ventricular apex. In the 14 patients with documented exudative effusions (10 pericardial, 4 pleural) NMR signals of varying intensity were present in the effusion. One patient had a documented transudative effusion and no NMR signal was observed in the fluid. NMR imaging clearly distinguished pericardial from pleural effusions. NMR imaging is indicated when a suspected pericardial effusions is not detected by echocardiography or when specific localization or fluid characterization is desired.


Asunto(s)
Ecocardiografía Doppler , Imagen por Resonancia Magnética , Derrame Pericárdico/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Exudados y Transudados/análisis , Femenino , Humanos , Masculino , Persona de Mediana Edad
19.
Am J Cardiol ; 64(3): 172-9, 1989 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-2741827

RESUMEN

The present study was intended to establish the feasibility, safety and usefulness of conventional spin-echo nuclear magnetic resonance (NMR) imaging for the detection of acute myocardial infarction within 24 hours of the onset of chest pain. Monitoring facilities were established in the NMR imaging suite that provided the same level of reliability and safety found in a standard coronary care unit. An imaging protocol was developed that allowed the acquisition of a complete study in 30 minutes while providing useful information about mechanical function and myocardial tissue contrast. Eighteen postthrombolysis patients were imaged within 21 +/- 2 hours of chest pain onset. No patient developed recurrent chest pain or arrhythmias in the NMR imaging suite. Relatively T2-weighted spin-echo images (echo time = 60 ms; repetition time = heart rate) provided interpretable images in 16 patients. Fourteen normal subjects were imaged for comparison. Thirteen of 16 patients had an increase in signal intensity in the region of the infarction. Regional wall thickening was assessed using a floating endocardial centroid technique. Wall motion abnormalities detected by NMR corresponded to those noted by 2-dimensional echocardiography and contrast angiography. Sensitivity, specificity and accuracy for the detection of infarction were 93, 80 and 87%, respectively, when signal intensity and wall thickening abnormalities were combined. In summary, NMR imaging is feasible in patients with acute myocardial infarction within 24 hours of chest pain onset. The study can be conducted safely and it provides useful information about acute myocardial infarction.


Asunto(s)
Imagen por Resonancia Magnética , Infarto del Miocardio/diagnóstico , Adulto , Anciano , Angina de Pecho/complicaciones , Cateterismo Cardíaco , Ecocardiografía , Electrocardiografía , Femenino , Humanos , Aumento de la Imagen , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Infarto del Miocardio/fisiopatología , Factores de Tiempo
20.
Am J Cardiol ; 57(13): 1059-65, 1986 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-3706158

RESUMEN

Experimental canine studies have demonstrated the potential of magnetic resonance imaging (MRI) for detecting and characterizing acute myocardial infarction (AMI) in humans. Accordingly, electrocardiographic-gated spin-echo MR images of the left ventricular short axis were obtained in 34 patients a mean of 11 +/- 6 days (range 3 to 30) after AMI. This imaging technique allowed division of the left ventricle into segments corresponding to the left ventricular segments on angiography. Patients were separated into 2 groups; the first 16 patients (group I) were examined using a variety of imaging techniques. Information derived from this experience resulted in a standard imaging protocol and development of criteria for the presence of AMI. The imaging protocol and interpretation criteria were used in the assessment of a subsequent group of 18 patients (group II). Of the 14 patients in group II with satisfactory image quality, all showed an increase in myocardial signal intensity consistent with an AMI. In addition, the anterior or inferior location of the abnormal MR segments corresponded to the electrocardiographic infarct location. MR segments showing increased signal intensity corresponded with severely hypokinetic or akinetic segments on the left ventriculogram in 8 patients having both procedures. In a group of volunteers who underwent imaging and whose images were interpreted in the same manner as those of the patients with AMI, 1 of 9 subjects had regional variation in myocardial signal intensity compatible with an AMI. In summary, AMI is readily detected, located and characterized by electrocardiographic-gated MRI. These findings suggest that MRI techniques may have a role in the evaluation of AMI in humans.


Asunto(s)
Espectroscopía de Resonancia Magnética , Infarto del Miocardio/diagnóstico , Adulto , Anciano , Cateterismo Cardíaco , Electrocardiografía , Femenino , Corazón/fisiología , Corazón/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Valores de Referencia , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA