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1.
Nature ; 604(7906): 525-533, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35388223

RESUMO

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.


Assuntos
Encéfalo , Longevidade , Estatura , Encéfalo/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética/métodos , Neuroimagem
3.
Microvasc Res ; 114: 46-51, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28619664

RESUMO

Pulmonary arterial hypertension (PAH) represents one of the main clinical expressions of the vascular changes in systemic sclerosis (SSc). Lung microvascular changes can play a role in the pathogenesis of idiopathic PAH (IPAH) also. The aim of this study is to investigate the presence of capillaroscopic abnormalities in patients with IPAH and to evaluate the differences in capillary nailfold changes between patients with IPAH and patients with SSc with and without PAH. METHODS: 39 SSc patients (19 with PAH - SSc-PAH and 20 without - SSc-noPAH), 21 subjects with IPAH and 20 healthy subjects were recruited. PAH was diagnosed by right heart catheterization. Nailfold videocapillaroscopy was performed (NVC) in all recruited subjects; capillary quantitative parameters (loops length and width, capillary density, neoangiogenesis) were evaluated and a semiquantitative scoring was used (normal, minor or major abnormalities for healthy controls and IPAH subjects and specific patterns - early, active and late - for SSc subjects) to define microvascular alterations. RESULTS: The presence of capillaroscopic abnormalities was detected in 38,1% subjects with IPAH; particularly, compared to healthy controls, capillary density was significantly lower (7,5±1,65loops/mm vs 9±1,37loops/mm p<0,05) and mean capillary width was significantly higher (21±13µm vs 17±3µm p<0,05). A more severe NVC pattern (active/late) was described. SSc-PAH patients compared to SSc-noPAH patients (73,2% vs 50% respectively, p<0,05), with a significantly lower capillary density (5,64±1,9loops/mm vs 6,5±1,3loops/mm p<0,05) and a significantly higher capillary width (55±7µm vs 35±8µm - p<0,05) and mean number of neoangiogenesis (N/mm) (1±0,33 vs 0,2±0,22 respectively p<0,05). CONCLUSIONS: These data, beyond to confirm the role of microvascular damage in SSc-related PAH, support the hypothesis of systemic microvascular involvement in IPAH also, which can be detected by NVC, although further studies are needed to establish whether the changes in the systemic microcirculation are causal or consequential to PAH.


Assuntos
Capilares/patologia , Hipertensão Pulmonar Primária Familiar/patologia , Hipertensão Pulmonar/patologia , Angioscopia Microscópica , Unhas/irrigação sanguínea , Escleroderma Sistêmico/patologia , Adulto , Pressão Arterial , Estudos de Casos e Controles , Hipertensão Pulmonar Primária Familiar/fisiopatologia , Feminino , Humanos , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica , Valor Preditivo dos Testes , Artéria Pulmonar/fisiopatologia , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/fisiopatologia
4.
Psychol Med ; 47(16): 2797-2810, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28528586

RESUMO

BACKGROUND: White matter disruptions in schizophrenia have been widely reported, but it remains unclear whether these abnormalities differ between illness stages. We mapped the connectome in patients with recently diagnosed and chronic schizophrenia and investigated the extent and overlap of white matter connectivity disruptions between these illness stages. METHODS: Diffusion-weighted magnetic resonance images were acquired in recent-onset (n = 19) and chronic patients (n = 45) with schizophrenia, as well as age-matched controls (n = 87). Whole-brain fiber tracking was performed to quantify the strength of white matter connections. Connections were tested for significant streamline count reductions in recent-onset and chronic groups, relative to separate age-matched controls. Permutation tests were used to assess whether disrupted connections significantly overlapped between chronic and recent-onset patients. Linear regression was performed to test whether connectivity was strongest in controls, weakest in chronic patients, and midway between these extremities in recent-onset patients (controls > recent-onset > chronic). RESULTS: Compared with controls, chronic patients displayed a widespread network of connectivity disruptions (p < 0.01). In contrast, connectivity reductions were circumscribed to the anterior fibers of the corpus callosum in recent-onset patients (p < 0.01). A significant proportion of disrupted connections in recent-onset patients (86%) coincided with disrupted connections in chronic patients (p < 0.01). Linear regression revealed that chronic patients displayed reduced connectivity relative to controls, while recent-onset patients showed an intermediate reduction compared with chronic patients (p < 0.01). CONCLUSIONS: Connectome pathology in recent-onset patients with schizophrenia is confined to select tracts within a more extensive network of white matter connectivity disruptions found in chronic illness. These findings may suggest a trajectory of progressive deterioration of connectivity in schizophrenia.


Assuntos
Conectoma , Corpo Caloso/patologia , Rede Nervosa/patologia , Transtornos Psicóticos/patologia , Esquizofrenia/patologia , Substância Branca/patologia , Adulto , Fatores Etários , Idade de Início , Doença Crônica , Corpo Caloso/diagnóstico por imagem , Imagem de Tensor de Difusão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Transtornos Psicóticos/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Adulto Jovem
5.
Food Microbiol ; 45(Pt A): 2-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25481056

RESUMO

This study aims at the characterisation of growth behaviour of three strains of Bacillus amyloliquefaciens, isolated from ropy bread (ATCC8473), wheat grain (ISPA-S109.3) and semolina (ISPA-N9.1) to estimate rope spoilage risk in pan bread during shelf-life using the Sym'Previus tool. Cardinal values and growth/no growth boundaries were determined in broth, while artificial spore inoculations were performed in dough for various pan bread recipes to compare experimental counts with in silico growth simulations. Finally, two storage scenarios were tested to determine the probability to reach a spoilage threshold during bread shelf-life. Similarly to the safety criteria fixed for Listeria monocytogenes contamination in foodstuff complying with EC regulation, a potential rope spoilage threshold was arbitrary fixed at 5 log CFU/g for B. amyloliquefaciens. This study further underlines a higher rope spoilage potential of the ISPA strains as compared to the ATCC strain, thus emphasizing the interest to characterise both wild strains and reference strain to account for biological variability. In conclusion, this study showed that available decision making tools which are largely recognized to predict behaviour of pathogenic strains, shall also be used with spoilage strains to help maintain food quality and extend shelf-life.


Assuntos
Bacillus amyloliquefaciens/crescimento & desenvolvimento , Pão/microbiologia , Microbiologia de Alimentos , Triticum/microbiologia , Bacillus amyloliquefaciens/genética , Contagem de Colônia Microbiana , Grão Comestível/microbiologia , Meio Ambiente , Contaminação de Alimentos , Manipulação de Alimentos , Concentração de Íons de Hidrogênio , Listeria monocytogenes/crescimento & desenvolvimento , Modelos Logísticos , Risco , Especificidade da Espécie , Esporos Bacterianos , Temperatura
6.
Allergol Immunopathol (Madr) ; 41(1): 25-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22417939

RESUMO

BACKGROUND: The aim was to investigate prognostic relevance of history of allergy in subjects with unstable angina treated with coronary angioplasty. METHODS: Fifty-seven consecutive patients with unstable angina who underwent coronary angioplasty were enrolled in the study and were divided into two groups: those with a history of allergy (Group A, N = 15); and controls (Group C, N =42). Major adverse cardiac events were recorded over a six-month follow-up period. Patients with primary or unsuccessful angioplasty and patients treated with drug eluting stent were excluded from the study. RESULTS: Group A patients (history of allergy) showed a 46.67% incidence of major adverse cardiac events at six-month follow-up (vs. 9.52% Group C, p < 0.01): results remained significant even in a multiple Cox regression analysis (hazard ratio 7.17, 95% CI 1.71-29.98, p < 0.01). CONCLUSION: History of allergy is an independent predictor of major adverse cardiac events after coronary angioplasty in a six-month follow-up period in unstable angina.


Assuntos
Angina Instável/cirurgia , Angioplastia Coronária com Balão/efeitos adversos , Hipersensibilidade/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Idoso , Morte Súbita , Feminino , Seguimentos , Humanos , Incidência , Masculino , Anamnese , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Valor Preditivo dos Testes , Prognóstico , Recidiva , Resultado do Tratamento
7.
Neth Heart J ; 21(9): 408-16, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23712465

RESUMO

BACKGROUND: Few works have evaluated the effect of statins on left ventricular dysfunction in patients with chronic heart failure (CHF), by using tissue Doppler imaging (TDI). We therefore aimed to investigate whether atorvastatin treatment may influence prognosis and myocardial performance evaluated by TDI in subjects with CHF. METHODS: Five hundred thirty-two consecutive CHF outpatients enrolled in a local registry, the Daunia Heart Failure Registry, were prospectively analysed. 195 patients with CHF and left ventricular ejection fraction (LVEF) ≤40 %, either in treatment with atorvastatin (N: 114) or without statins (N: 81), underwent TDI examination. Adverse events were evaluated during follow-up. RESULTS: The atorvastatin group showed a lower incidence of adverse events (cardiac death: 0 % vs 7 %, p < 0.01), and better TDI performance (E/E' 15 ± 5.7 vs 18 ± 8.3, p < 001) than controls. Ischaemic CHF patients in treatment with atorvastatin also showed a lower incidence of adverse events (death: 10 % vs 26 %, p < 0.05; sustained ventricular arrhythmias: 5 % vs 19 %, p < 0.05, cardiac death: 0 vs 8 %, p < 0.05) and better TDI performance (E/E' ratio: 15.00 ± 5.68 vs 19.72 ± 9.14, p < 0.01; St: 353.70 ± 48.96 vs 303.33 ± 68.52 msec, p < 0.01) than controls. The association between atorvastatin and lower rates of cardiac death remained statistically significant even after correction in a multivariable analysis (RR 0.83, 95 % CI 0.71-0.96, p < 0.05 in CHF with LVEF ≤40 %; RR 0.77, 95 % CI 0.62-0.95, p < 0.05 in ischaemic CHF with LVEF ≤40 %). CONCLUSIONS: Treatment with atorvastatin in outpatients with systolic CHF is associated with fewer cardiac deaths, and a better left ventricular performance, as assessed by TDI.

8.
Neth Heart J ; 21(1): 36-43, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23151817

RESUMO

BACKGROUND: The cardiopulmonary exercise test (CPX) is an affordable tool for risk prediction in patients with chronic heart failure (CHF). We aimed to determine the role of CPX parameters in predicting the risk of incidence of sustained ventricular arrhythmias (SVA) in CHF. METHODS: Sixty-one consecutive patients with CHF enrolled in the Daunia Heart Failure Registry underwent CPX and were followed for 327 ± 247 days. Clinical follow-up was performed every month and anticipated in case of re-hospitalisation for cardiac disease. Incidence of SVA was evaluated by direct clinical examination (ECG, ambulatory ECG). RESULTS: Patients with episodes of SVA (N 14) showed lower values of pVO2 and PetCO2, and higher values of VE/VCO2, VE/VCO2 slope, and VE%. After correction for age, gender, diabetes, ischaemic heart disease and left ventricular ejection fraction, peak VO2 (hazard ratio (HR) 0.68, 95 % confidence interval (CI) 0.51-0.91, p < 0.05), VE% (HR 1.38, 95 % CI 1.04-1.84, p < 0.05), VE/VCO2 (HR 1.38, 95 % CI 1.04-1.82, p < 0.05), VE/VCO2 slope (HR 1.77, 95 % CI 1.31-2.39, p < 0.01), PetCO2 (HR 0.66, 95 % CI 0.50-0.88, p < 0.01) were found as predictors of SVA. At Kaplan-Meier analysis, lower event-free rates were found in subjects with peak VO2 values below median (log rank p < 0.05), values of VE/VCO2 above mean (p < 0.05), higher VE/VCO2 slope tertiles (p <0.05), and values of PetCO2 below median (p < 0.05). CONCLUSIONS: CPX provides prognostic independent information for risk of SVA in subjects with CHF.

10.
Minerva Cardioangiol ; 57(4): 443-55, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19763067

RESUMO

In the latest years several manuscripts have showed some new possible advantages of the three-dimensional (3D) echocardiography in daily practice. 3D echocardiography allows imaging and analysis of cardiovascular structures as they move in time and space, thus creating possibility for creation of 4D datasets (3D and real-time). Real-time three-dimensional echocardiography (RT3DE) is a major innovation in the history of cardiovascular ultrasound. Advances in computer and transducer technologies, especially the fully-sampled matrix array transducer, have permitted real-time 3D image acquisition and display. The aim of this manuscript is to give a brief review of the development of the 3D echocardiography and of comparison of two-dimensional echocardiography versus 3D echocardiography and RT3DE.


Assuntos
Tecnologia Biomédica , Ecocardiografia Quadridimensional , Ecocardiografia Tridimensional , Ecocardiografia Transesofagiana/métodos , Ecocardiografia , Artefatos , Doença das Coronárias/diagnóstico por imagem , Ecocardiografia Quadridimensional/métodos , Ecocardiografia Tridimensional/métodos , Endocardite/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Próteses Valvulares Cardíacas , Humanos , Sistemas On-Line , Ultrassonografia Doppler em Cores/métodos
11.
Transl Psychiatry ; 7(8): e1225, 2017 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-28850113

RESUMO

We examined putative microglial activation as a function of illness course in schizophrenia. Microglial activity was quantified using [11C](R)-(1-[2-chrorophynyl]-N-methyl-N-[1-methylpropyl]-3 isoquinoline carboxamide (11C-(R)-PK11195) positron emission tomography (PET) in: (i) 10 individuals at ultra-high risk (UHR) of psychosis; (ii) 18 patients recently diagnosed with schizophrenia; (iii) 15 patients chronically ill with schizophrenia; and, (iv) 27 age-matched healthy controls. Regional-binding potential (BPND) was calculated using the simplified reference-tissue model with four alternative reference inputs. The UHR, recent-onset and chronic patient groups were compared to age-matched healthy control groups to examine between-group BPND differences in 6 regions: dorsal frontal, orbital frontal, anterior cingulate, medial temporal, thalamus and insula. Correlation analysis tested for BPND associations with gray matter volume, peripheral cytokines and clinical variables. The null hypothesis of equality in BPND between patients (UHR, recent-onset and chronic) and respective healthy control groups (younger and older) was not rejected for any group comparison or region. Across all subjects, BPND was positively correlated to age in the thalamus (r=0.43, P=0.008, false discovery rate). No correlations with regional gray matter, peripheral cytokine levels or clinical symptoms were detected. We therefore found no evidence of microglial activation in groups of individuals at high risk, recently diagnosed or chronically ill with schizophrenia. While the possibility of 11C-(R)-PK11195-binding differences in certain patient subgroups remains, the patient cohorts in our study, who also displayed normal peripheral cytokine profiles, do not substantiate the assumption of microglial activation in schizophrenia as a regular and defining feature, as measured by 11C-(R)-PK11195 BPND.


Assuntos
Encéfalo/metabolismo , Microglia/metabolismo , Transtornos Psicóticos/complicações , Transtornos Psicóticos/metabolismo , Receptores de GABA/metabolismo , Esquizofrenia/complicações , Esquizofrenia/metabolismo , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Radioisótopos de Carbono , Feminino , Humanos , Isoquinolinas , Masculino , Tomografia por Emissão de Pósitrons , Fatores de Risco , Esquizofrenia/diagnóstico , Adulto Jovem
13.
Br J Pharmacol ; 173(4): 666-80, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26455353

RESUMO

Schizophrenia is a debilitating disorder that typically begins in adolescence and is characterized by perceptual abnormalities, delusions, cognitive and behavioural disturbances and functional impairments. While current treatments can be effective, they are often insufficient to alleviate the full range of symptoms. Schizophrenia is associated with structural brain abnormalities including grey and white matter volume loss and impaired connectivity. Recent findings suggest these abnormalities follow a neuroprogressive course in the earliest stages of the illness, which may be associated with episodes of acute relapse. Neuroinflammation has been proposed as a potential mechanism underlying these brain changes, with evidence of increased density and activation of microglia, immune cells resident in the brain, at various stages of the illness. We review evidence for microglial dysfunction in schizophrenia from both neuroimaging and neuropathological data, with a specific focus on studies examining microglial activation in relation to the pathology of grey and white matter. The studies available indicate that the link between microglial dysfunction and brain change in schizophrenia remains an intriguing hypothesis worthy of further examination. Future studies in schizophrenia should: (i) use multimodal imaging to clarify this association by mapping brain changes longitudinally across illness stages in relation to microglial activation; (ii) clarify the nature of microglial dysfunction with markers specific to activation states and phenotypes; (iii) examine the role of microglia and neurons with reference to their overlapping roles in neuroinflammatory pathways; and (iv) examine the impact of novel immunomodulatory treatments on brain structure in schizophrenia.


Assuntos
Encéfalo/patologia , Microglia/patologia , Esquizofrenia/patologia , Animais , Encéfalo/fisiopatologia , Humanos , Inflamação/patologia , Inflamação/fisiopatologia , Esquizofrenia/fisiopatologia
14.
J Am Coll Cardiol ; 5(5): 1212-9, 1985 May.
Artigo em Inglês | MEDLINE | ID: mdl-3989134

RESUMO

This study was carried out to further elucidate the effects of adenosine and adenosine-5'-triphosphate (ATP) on atrioventricular (AV) conduction in patients. Adenosine (0.24 mg/kg) and ATP (0.28 mg/kg) were administered intravenously to 37 patients undergoing intracardiac electrophysiologic evaluation. Both adenosine and ATP depressed AV conduction by lengthening the atrial to His bundle (AH) interval. The effects of adenosine and ATP after rapid intravenous bolus administration were fast in onset (15 +/- 0.5 and 15 +/- 1.5 s, respectively), but transient in duration (10.5 +/- 0.5 s for ATP and 17 +/- 3 s for adenosine). Although muscarinic blockade with 0.04 mg/kg atropine shortened the AH interval from a control value of 123 +/- 12 to 74 +/- 4 ms, it did not modify the effects of adenosine or ATP, or both (that is, latency and duration of the effects were not significantly different from before atropine administration). In contrast, aminophylline, a competitive antagonist of adenosine, completely prevented the effects of adenosine and ATP. Aminophylline alone also shortened the AH interval from a control value of 98 +/- 9 to 74 +/- 9 ms. This decrease was blocked by propranolol (0.1 mg/kg), whereas propranolol did not influence the ability of aminophylline to antagonize the effects of adenosine or ATP, or both. Thus, the catecholamines released by aminophylline are unlikely to account for the ability of aminophylline to antagonize the effects of adenosine and ATP. In conclusion, these findings indicate that intravenously administered adenosine and ATP are equally effective in producing AV block that is antagonized by aminophylline but not by atropine.


Assuntos
Trifosfato de Adenosina/farmacologia , Adenosina/farmacologia , Nó Atrioventricular/efeitos dos fármacos , Sistema de Condução Cardíaco/efeitos dos fármacos , Adenosina/antagonistas & inibidores , Trifosfato de Adenosina/antagonistas & inibidores , Adulto , Aminofilina/farmacologia , Nó Atrioventricular/fisiopatologia , Atropina/farmacologia , Fascículo Atrioventricular/efeitos dos fármacos , Fascículo Atrioventricular/fisiopatologia , Estimulação Cardíaca Artificial , Eletrocardiografia , Feminino , Bloqueio Cardíaco/induzido quimicamente , Bloqueio Cardíaco/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade
15.
J Am Coll Cardiol ; 37(5): 1259-65, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11300432

RESUMO

OBJECTIVES: We sought to compare the efficacy of aspirin and ticlopidine in survivors of acute myocardial infarction (AMI) treated with thrombolysis. BACKGROUND: The role of ticlopidine in secondary prevention after AMI has not yet been explored. METHODS: Of 4,696 patients with AMI treated with thrombolysis who were screened, 261 died in the hospital (5.6%) and 1,470 were enrolled in this randomized, double-blind, multicenter trial and allocated to treatment with either aspirin (160 mg/day) or ticlopidine (500 mg/day). The most frequent reasons for exclusion were refusal to give informed consent, planned myocardial revascularization, risk of noncompliance with study procedures, need for anticoagulant therapy and contraindications to the study treatments. The primary end point was the first occurrence of any of the following events during the six-month follow-up: fatal and nonfatal AMI, fatal and nonfatal stroke, angina with objective evidence of myocardial ischemia, vascular death or death due to any other cause. RESULTS: The primary end point was recorded in 59 (8.0%) of the 736 aspirin-treated and 59 (8.0%) of the 734 ticlopidine-treated patients (p = 0.966). Vascular death was the first event in five patients taking aspirin and in six patients taking ticlopidine (0.7% vs. 0.8%; p = NS); nonfatal AMI in 18 and 8 (2.4% vs. 1.1%; p = 0.049); nonfatal stroke in 3 and 4 (0.4% vs. 0.5%; p = NS); and angina in 33 and 40 (4.5% vs. 5.4%; p = NS), respectively. The frequency of adverse reactions was not significantly different between the two groups. CONCLUSIONS: No difference was found between the ticlopidine and aspirin groups in the rate of the primary combined end point of death, recurrent AMI, stroke and angina.


Assuntos
Aspirina/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Terapia Trombolítica , Ticlopidina/uso terapêutico , Adulto , Idoso , Aspirina/efeitos adversos , Causas de Morte , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Recidiva , Taxa de Sobrevida , Ticlopidina/efeitos adversos
16.
J Am Coll Cardiol ; 26(2): 380-7, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7608438

RESUMO

OBJECTIVES: This study was performed to evaluate the effects of L-carnitine administration on long-term left ventricular dilation in patients with acute anterior myocardial infarction. BACKGROUND: Carnitine is a physiologic compound that performs an essential role in myocardial energy production at the mitochondrial level. Myocardial carnitine deprivation occurs during ischemia, acute myocardial infarction and cardiac failure. Experimental studies have suggested that exogenous carnitine administration during these events has a beneficial effect on function. METHODS: The L-Carnitine Ecocardiografia Digitalizzata Infarto Miocardico (CEDIM) trial was a randomized, double-blind, placebo-controlled, multicenter trial in which 472 patients with a first acute myocardial infarction and high quality two-dimensional echocardiograms received either placebo (239 patients) or L-carnitine (233 patients) within 24 h of onset of chest pain. Placebo or L-carnitine was given at a dose of 9 g/day intravenously for the first 5 days and then 6 g/day orally for the next 12 months. Left ventricular volumes and ejection fraction were evaluated on admission, at discharge from hospital and at 3, 6 and 12 months after acute myocardial infarction. RESULTS: A significant attenuation of left ventricular dilation in the first year after acute myocardial infarction was observed in patients treated with L-carnitine compared with those receiving placebo. The percent increase in both end-diastolic and end-systolic volumes from admission to 3-, 6- and 12-month evaluation was significantly reduced in the L-carnitine group. No significant differences were observed in left ventricular ejection fraction changes over time in the two groups. Although not designed to demonstrate differences in clinical end points, the combined incidence of death and congestive heart failure after discharge was 14 (6%) in the L-carnitine treatment group versus 23 (9.6%) in the placebo group (p = NS). Incidence of ischemic events during follow-up was similar in the two groups of patients. CONCLUSIONS: L-Carnitine treatment initiated early after acute myocardial infarction and continued for 12 months can attenuate left ventricular dilation during the first year after an acute myocardial infarction, resulting in smaller left ventricular volumes at 3, 6 and 12 months after the emergent event.


Assuntos
Carnitina/uso terapêutico , Hipertrofia Ventricular Esquerda/prevenção & controle , Infarto do Miocárdio/tratamento farmacológico , Adulto , Idoso , Análise de Variância , Carnitina/administração & dosagem , Método Duplo-Cego , Esquema de Medicação , Ecocardiografia , Feminino , Seguimentos , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/etiologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico por imagem , Reprodutibilidade dos Testes , Resultado do Tratamento , Função Ventricular Esquerda/efeitos dos fármacos
17.
Cardiovasc Res ; 32(2): 226-33, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8796108

RESUMO

OBJECTIVE: To obtain data relating to the reproducibility of the time and frequency domain measurements obtained from 10-min ECG recordings. METHODS: Eighteen normal volunteers underwent evaluations of time and frequency domain heart rate variability 2 weeks and 7 months after baseline analysis. The time domain parameters were mean NN, the standard deviation of NN intervals, the percentage of successive NN intervals > 50 ms and the root mean square successive difference of NN intervals. The frequency domain evaluations (total power, low frequency, and high frequency) were made by means of both the Fast Fourier Transform algorithm (FFT) and the autoregressive method (AR) from 10-min ECG recordings made under three different conditions: rest, controlled respiration, and after a passive head-up tilt test. Reproducibility was evaluated by means of the interclass correlation coefficient (ICC), comparing baseline values with the results obtained at the second week and the seventh month. Time domain evaluation were also made from 10-min ECG. RESULTS: All of the time domain measurements had an ICC > or = 0.75, except for the standard deviation of NN intervals, which had an ICC of 0.57. The frequency domain parameters obtained by means of either FFT or AR showed similar reproducibility. Low frequency was reproducible under all three conditions, total power only at rest, and high frequency only during controlled respiration. CONCLUSION: The reproducibility of frequency domain parameters depends on the analysed condition. These results are of primary importance when the effects of drugs or other interventions on heart rate variability are under investigation.


Assuntos
Eletrocardiografia , Frequência Cardíaca/fisiologia , Processamento de Sinais Assistido por Computador , Adulto , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Teste da Mesa Inclinada
18.
Int J Cardiol ; 49(3): 215-23, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7649667

RESUMO

This study was undertaken to assess the relation of ambulatory myocardial ischemia to heart rate changes and variability in exercise threshold in patients with chronic angina. The study involved 118 patients with chronic angina and proven coronary artery disease who had a 'positive' exercise test result. All patients underwent a first exercise test followed by a 48-h period of ambulatory electrocardiographic monitoring. A second exercise test was performed 4 days later. A total of 101 ischemic episodes were recorded in 35 patients. The heart rate at the appearance of 1-mm ST segment depression during ambulatory electrocardiographic monitoring was > or = 20 beats/min lower than that during exercise testing in 58 ischemic episodes (57%, Group A), 10-19 beats/min lower in 26 (26%, Group B), and < or = 9 beats/min lower or higher in 17 (17%, Group C). Thirty-five percent of the Group A ischemic episodes, 69% of Group B, and 71% of Group C were preceded by an increase in heart rate of > or = 10 beats/min. Thirty patients showed a variable exercise threshold. The prevalence of Group A and B ischemic episodes was not significantly different in patients with fixed or variable exercise threshold, whereas that of Group C episodes was 22% in the former and 0% in the latter (P = 0.036). These results suggest that increased coronary tone may be one of the mechanisms contributing to modulate the occurrence of transient myocardial ischemia in most patients with chronic angina and transient myocardial ischemia at ambulatory electrocardiographic monitoring. This occurs regardless of whether the patients have a variable or fixed exercise threshold.


Assuntos
Angina Pectoris/fisiopatologia , Frequência Cardíaca , Isquemia Miocárdica/fisiopatologia , Periodicidade , Análise de Variância , Angina Pectoris/complicações , Distribuição de Qui-Quadrado , Doença Crônica , Eletrocardiografia Ambulatorial , Teste de Esforço , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/complicações , Estudos Prospectivos , Fatores de Tempo
19.
Int J Cardiol ; 22(2): 177-83, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2914741

RESUMO

The acute electrophysiological effects of intravenous nicardipine (0.014 mg/kg per min for 5 minutes) were studied in 12 subjects with estimated normal sinus node functions and atrioventricular conduction parameters. The most important effects were sinus cycle length shortening, increase of corrected sinus node recovery time and reduction of effective and functional refractory period of the atrioventricular node. Sinuatrial conduction time, atrial refractory periods, intranodal conduction, bundle branch refractoriness and ventricular refractoriness were unchanged. Systolic and diastolic blood pressure was reduced. The clinical implications of these properties of the drug are discussed and compared with those of verapamil, diltiazem and nifedipine.


Assuntos
Eletrocardiografia , Sistema de Condução Cardíaco/efeitos dos fármacos , Nicardipino/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Fascículo Atrioventricular/efeitos dos fármacos , Cardiomiopatia Hipertrófica/tratamento farmacológico , Doença das Coronárias/tratamento farmacológico , Átrios do Coração/efeitos dos fármacos , Humanos , Hipertensão/tratamento farmacológico , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Nó Sinoatrial/efeitos dos fármacos
20.
Int J Cardiol ; 30(3): 329-33, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2055673

RESUMO

L-propionylcarnitine, a short-chain acylcarnitine, has been shown in experimental studies to induce, during acidic and hypoxic conditions, some electrophysiological changes such as an increase of duration of the action potential and of the effective refractory period. In this study, the acute electrophysiological effects of intravenous L-propionylcarnitine (30 mg/kg in 3 min) were studied in 12 subjects with estimated normal function of the sinus node and normal parameters for atrioventricular conduction. Statistically significant changes were observed 2 min after infusion. The sinus cycle length shortened (866 +/- 138 vs 818 +/- 124 msec, P less than 0.05) while refractory periods of the atrioventricular node increased (effective by 30-50 msec in four cases; functional from 425 +/- 52 to 436 +/- 55 msec, P less than 0.05). Sinuatrial conduction time, atrial refractory periods, infranodal conduction, bundle branch, His-Purkinje system and ventricular refractoriness were unchanged. Systolic and diastolic blood pressure were also unchanged. Because of the limited effects on electrophysiological parameters, L-propionylcarnitine should be used as a metabolic drug even in patients with mild disturbances of conduction.


Assuntos
Carnitina/análogos & derivados , Sistema de Condução Cardíaco/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Carnitina/deficiência , Carnitina/farmacologia , Cateterismo Periférico , Eletrofisiologia , Feminino , Átrios do Coração/efeitos dos fármacos , Sistema de Condução Cardíaco/fisiologia , Ventrículos do Coração/efeitos dos fármacos , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Período Refratário Eletrofisiológico/efeitos dos fármacos , Nó Sinoatrial/efeitos dos fármacos , Fatores de Tempo
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