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1.
J Am Soc Echocardiogr ; 35(10): 1028-1036, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35817379

RESUMO

BACKGROUND: Contemporary data on the independent association of severe tricuspid regurgitation (TR) with excess mortality are needed. The aims of this study were to describe contemporary outcomes of patients with severe TR and to identify outcome modifiers. METHODS: Consecutive echocardiographic reports linked to clinical data from the largest medical center in Israel (2007-2019) were reviewed. The primary outcome was all-cause mortality. Cox regression and propensity score matching models were applied. RESULTS: The final cohort included 97,096 patients. Mild, moderate, and severe TR was documented in 27,147 (28%), 2,844 (3%) and 1,805 (2%) patients, respectively. During a median follow-up period of 5 years (interquartile range, 2-8 years), 22,170 patients (23%) died. Kaplan-Meier survival analysis demonstrated an increased risk for death with an increasing degree of TR (log-rank P < .001). Propensity score matching of 1,265 patients with severe TR and matched control subjects showed that compared with those with nonsevere TR, patients with severe TR were 17% more likely to die (95% CI, 1.05-1.29; P = .003). The association of severe TR with survival was dependent on estimated right ventricular (RV) pressure, with a more pronounced effect among patients with estimated systolic pressure ≤ 40 mm Hg (hazard ratio, 2.12 vs 1.04; P for interaction < .001). A landmark subanalysis of 17,967 patients demonstrated that RV function deterioration on follow-up echocardiography modified the association of severe TR with survival. It was more significant among patients with preserved and stable RV function (P for interaction = .035). CONCLUSIONS: The outcome of severe TR is modified by RV pressure and function. Once RV function deteriorates, differences in the outcomes of patients with and without severe TR are less pronounced.


Assuntos
Insuficiência da Valva Tricúspide , Big Data , Ecocardiografia , Humanos , Estudos Retrospectivos , Insuficiência da Valva Tricúspide/complicações , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Função Ventricular Direita , Pressão Ventricular
2.
J Am Soc Echocardiogr ; 35(4): 378-386.e3, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34915134

RESUMO

BACKGROUND: Data on the independent association of moderate aortic stenosis (AS) with excess mortality, even when it does not progress to severe AS, are limited. The aims of this study were to evaluate the association of moderate AS with poor survival and to identify clinically important modifiers of that association. METHODS: Consecutive patients who underwent echocardiographic evaluation between 2007 and 2019 were included. All-cause mortality and cancer data were available for all patients from national registries. Cox regression survival models were applied, with censoring of patients who developed metastatic cancer, developed more than moderate AS, or underwent aortic valve intervention during follow-up. RESULTS: The study population included 92,622 patients. There were 2,202 patients (2%) with moderate AS, with a median age of 79 years (interquartile range, 70-85 years), of whom 1,254 (57%) were men. During median follow-up of 5 years (interquartile range, 3-8 years), 19,712 patients (21%) died. The cumulative probability of death at 5 years was higher for patients with moderate AS (46% vs 18%, respectively, log-rank P < .001). Propensity score matching analysis (n = 2,896) that included clinical, laboratory, and echocardiographic predictors of poor survival demonstrated that compared with patients with mild or less AS, those with moderate AS were 17% more likely to die (95% CI, 1.04-1.30; P = .007). Moreover, the model showed that the moderate AS-associated risk was ejection fraction and age dependent, with a more pronounced association among nonoctogenarian patients (P for interaction = .001) and those with reduced ejection fractions (P for interaction = .016). CONCLUSIONS: Moderate AS is independently associated with excess mortality, even when it does not progress to severe AS. The associated risk is more pronounced among patients with reduced ejection fractions and those <80 years of age.


Assuntos
Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/cirurgia , Big Data , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda
3.
Cardiol J ; 29(2): 245-251, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34708864

RESUMO

BACKGROUND: The treatment of choice for severe rheumatic mitral stenosis (MS) is balloon mitral valvuloplasty (BMV). Assessment of MS severity is usually performed by echocardiography. Before performing BMV, invasive hemodynamic assessment is also performed. The effect of anesthesia on the invasive assessment of MS severity has not been studied. The purpose of the present study was to assess changes in invasive hemodynamic measurement of MS severity before and after induction of general anesthesia. METHODS: The medical files of 22 patients who underwent BMV between 2014 and 2020 were reviewed. Medical history, laboratory, echocardiographic and invasive measurements were collected. Anesthesia induction was performed with etomidate or propofol. Pre-procedural echocardiographic measurements of valve area using pressure half time, and continuity correlated well with invasive measurements using the Gorlin formula. RESULTS: After induction of anesthesia the mean mitral valve gradient dropped by 2.4 mmHg (p = 0.153) and calculated mitral valve area (MVA) increased by 0.2 cm2 (p = 0.011). A wide variability in individual response was observed. While a drop in gradient was noted in 14 patients, it increased in 7. Gorlin derived MVA rose in most patients but dropped in 4. Assuming a calculated MVA of 1.5 cm2 and below to define clinically significant MS, 4 patients with pre-induction MVA of 1.5 cm2 or below had calculated MVA above 1.5 cm2 after induction. CONCLUSIONS: The impact of general anesthesia on the hemodynamic assessment of MS is heterogeneous and may lead to misclassification of MS severity.


Assuntos
Anestesia , Valvuloplastia com Balão , Estenose da Valva Mitral , Hemodinâmica , Humanos , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Estenose da Valva Mitral/diagnóstico
4.
Cardiology ; 146(3): 375-383, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33582661

RESUMO

BACKGROUND: Percutaneous device closure was shown to effectively prevent recurrent strokes in patients with patent foramen ovale (PFO). Whether this protective effect is relevant for patients with hypercoagulable states (HCSs) is unknown as they were not represented in prior studies. METHODS: Data on 136 consecutive patients with a PFO and clinically significant HCS were retrospectively collected. PFO closure and antithrombotic regimen were decided on an individual basis by the treating physicians, and adherence to therapy was routinely evaluated. The outcome was the occurrence of cerebrovascular accident (CVA) or transient ischemic attack (TIA). RESULTS: HCS types consisted of antiphospholipid syndrome (31%), factor-5 Leiden mutation (22%), prothrombin mutation (18%), protein S deficiency (15%), protein C deficiency (7%), methyl-tetra-hydro folate reductase mutation (5%), and essential thrombocytosis (2%). 102 patients (75%) were maintained on anticoagulants and the remaining on antiplatelet therapy. PFO closure was undertaken in 85 (63%); antithrombotic therapy was not interrupted prior to or after the procedures. At a mean follow-up of 46 ± 8 months, 23 patients (17%; 95% confidence interval, 9.3-22%) experienced an outcome event, mainly in the form of CVAs (n = 15, 65%). In multivariable analysis, PFO closure was associated with a 5-fold decrease in the risk of CVA/TIA (p = 0.02). This effect was independent of the type of HCS or antithrombotic therapy. CONCLUSIONS: Among patients with HCSs maintained on anticoagulant or antiplatelet therapies, PFO closure was associated with a significantly lower risk of CVA or TIA.


Assuntos
Forame Oval Patente , Ataque Isquêmico Transitório , Acidente Vascular Cerebral , Cateterismo Cardíaco , Fibrinolíticos/uso terapêutico , Forame Oval Patente/complicações , Forame Oval Patente/cirurgia , Humanos , Ataque Isquêmico Transitório/prevenção & controle , Recidiva , Estudos Retrospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Resultado do Tratamento
5.
Cardiol Young ; 29(6): 800-807, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31159904

RESUMO

BACKGROUND: Tricuspid valve regurgitation is an inherent part of Ebstein's anomaly, yet whether the severity of the regurgitation further impairs exercise capacity and contributes to long-term morbidity on top of the lesion severity per se is unknown. METHODS: To evaluate for this potential effect, we included 30 patients with Ebstein's anomaly who did not undergo any form of surgical interventions and had a cardiopulmonary exercise test and echocardiographic studies in this retrospective analysis. Echocardiographic studies and cardiopulmonary exercise tests were critically reviewed for lesion severity grade, tricuspid regurgitation degree, and exercise parameters. Cardiac-related hospitalisations were recorded from computerised medical records and during clinic visits. RESULTS: Fourteen patients (47%) had moderate and 8 (27%) had severe regurgitation. Patients with ≥ moderate regurgitation exhibited significantly lower exercise capacity (median % predicted maximal oxygen consumption, 62 versus 79%, p = 0.03) and venilatory efficiency at exercise. When stratifying exercise results by regurgitation degree, a stepwise decrease in oxygen consumption and ventilatory efficiency with increasing regurgitation severity was observed, regardless of the anatomic lesion severity. During a median follow-up of 4.6 years, > moderate tricuspid regurgitation was associated with significantly lower cumulative probability of freedom from cardiac hospitalisations. CONCLUSIONS: We report that among non-operated Ebstein's anomaly patients, greater tricuspid regurgitation severity was associated with worse exercise capacity and with overall higher probability of cardiac-related hospitalisations independent from the underlying lesion severity.


Assuntos
Anuloplastia da Valva Cardíaca/métodos , Anomalia de Ebstein/complicações , Tolerância ao Exercício/fisiologia , Hospitalização/tendências , Insuficiência da Valva Tricúspide/cirurgia , Valva Tricúspide/cirurgia , Adulto , Anomalia de Ebstein/diagnóstico , Ecocardiografia , Teste de Esforço , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/diagnóstico , Insuficiência da Valva Tricúspide/fisiopatologia , Função Ventricular Direita/fisiologia , Adulto Jovem
6.
Isr Med Assoc J ; 18(1): 18-22, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26964274

RESUMO

BACKGROUND: Transvenous lead extraction can lead to tricuspid valve damage. OBJECTIVES: To assess the incidence, risk factors and clinical outcome of tricuspid regurgitation (TR) following lead extraction. METHODS: We prospectively collected data on patients who underwent lead extraction at the Sheba Medical Center prior to laser use (i.e., before 2012). Echocardiography results before and following the procedure were used to confirm TR worsening, defined as an echocardiographic increase of at least one TR grade. Various clinical and echocardiographic parameters were analyzed as risk factors for TR. Clinical and echocardiographic follow-up was conducted to assess the clinical significance outcome of extraction-induced TR. RESULTS: Of 152 patients who underwent lead extraction without laser before 2012, 86 (56%) (192 electrodes) had echocardiography results before and within one week following the procedure. New or worsening TR was discovered in 13 patients (15%). Use of mechanical tools and younger age at extraction were found on multivariate analysis to be factors for TR development (P = 0.04 and P = 0.03 respectively). Average follow-up was 22.25 ± 21.34 months (range 8-93). There were no significant differences in the incidence of right-sided heart failure (50% vs. 23%, P = 0.192) or hospitalizations due to heart failure exacerbations (37.5% vs. 11%, P = 0.110). No patient required tricuspid valve repair or replacement. Death rates were similar in the TR and non-TR groups (20% vs. 33%). CONCLUSIONS: TR following lead extraction is not uncommon but does not seem to affect survival or outcomes such as need for valve surgery. Its long-term effects remain to be determined.


Assuntos
Remoção de Dispositivo/efeitos adversos , Eletrodos Implantados/efeitos adversos , Insuficiência Cardíaca/epidemiologia , Marca-Passo Artificial , Insuficiência da Valva Tricúspide/epidemiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia , Feminino , Seguimentos , Insuficiência Cardíaca/etiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Prospectivos , Fatores de Risco , Insuficiência da Valva Tricúspide/etiologia
7.
Heart ; 101(14): 1111-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25935768

RESUMO

OBJECTIVES: Cleft-like indentations (CLI) are deep separations between scallops of the mitral posterior leaflet observed in myxomatous mitral valve disease (MMVD), but their diagnosis, mechanisms and implications are unknown. Using 3D transoesophageal echocardiography (3DTOC), we aimed at assessing diagnostic accuracy and defining mechanisms of CLI in patients undergoing surgery for MMVD. METHODS: 3DTOC of mitral valve was acquired in 49 patients with MMVD and severe regurgitation prior to valve repair. Qualitative review compared 3DTOC diagnosis of CLI with surgical inspection. Mitral, annular and leaflet dimensions were quantified with dedicated software and compared between those with and without CLI. RESULTS: Diagnosis of CLI was made by 3DTOC in 17 (35%) while none was identified by 2D and was confirmed in 15 (88%) by surgical inspection. Mechanistically, LV diameters and mitral regurgitant volume (RVol) were similar with and without CLI (p>0.49). Conversely, mitral annulus was smaller with CLI (anteroposterior diameter 42.2±7.1 vs 47.0±7.5 mm, p=0.04; circumference 133±16 vs 148±19 mm, p=0.009; area 1289±326 vs 1619±427 mm(2), p=0.008). Prolapse volume tended to be smaller with CLI (1.9±1.2 vs 4.0±4.3 mL, p=0.06) involving single posterior scallop at surgery (82% vs 44%, p=0.007) with smaller 3DTOC leaflet area (1574±409 vs 2019±652 mm(2), p=0.01). During valve repair, surgical closure of all surgically diagnosed CLI was required. CONCLUSIONS: Posterior leaflet CLI are frequent in MMVD, are identified by 3DTOC with high accuracy and require closure during valve repair. CLI are mechanistically not related to excess annular enlargement or excess prolapse. Conversely, CLI occur in the context of single scallop prolapse with tissue paucity causing excess separation of scallops. These 3DTOC data enhance diagnostic and mechanistic comprehension of the diversity of MMVD phenotypical presentation.


Assuntos
Ecocardiografia Tridimensional , Ecocardiografia Transesofagiana , Insuficiência da Valva Mitral/diagnóstico por imagem , Prolapso da Valva Mitral/diagnóstico por imagem , Valva Mitral/diagnóstico por imagem , Idoso , Ecocardiografia Doppler , Feminino , Hemodinâmica , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valva Mitral/fisiopatologia , Valva Mitral/cirurgia , Insuficiência da Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/cirurgia , Prolapso da Valva Mitral/fisiopatologia , Prolapso da Valva Mitral/cirurgia , Valor Preditivo dos Testes , Estudos Prospectivos , Índice de Gravidade de Doença , Software , Resultado do Tratamento , Função Ventricular Esquerda
8.
Artigo em Inglês | MEDLINE | ID: mdl-25956922

RESUMO

BACKGROUND: Fibro-elastic deficiency (FED) and diffuse myxomatous degeneration (DMD) are phenotypes of degenerative mitral valve disease defined morphologically. Whether physiological differences in annular and valvular dynamics exist between these phenotypes remains unknown. METHODS AND RESULTS: We performed triple quantitation of cardiac remodeling and of mitral regurgitation severity and of annular and valvular dimensions by real-time 3-dimensional-transesophageal-echocardiography. Forty-nine patients with degenerative mitral valve disease classified as FED (n=31) and DMD (n=18) by surgical observation showed no difference in age (65±10 versus 59±13; P=0.5), body surface area (2.0±0.2 versus 2.0±0.2 m(2); P=0.5), left ventricular and atrial dimensions (all P>0.55), and mitral regurgitation regurgitant orifice (P=0.62). On average, annular dimensions were larger in DMD versus FED, but height was similar resulting in lower saddle shape. Dynamically, annular DMD versus FED display poorer contraction and saddle-shape accentuation in early systole and abnormal enlargement, particularly intercommissural, in late-systole (all P<0.05). Valvular dynamics showed stable valvular area in systole in FED versus considerable systolic increased area in DMD (P<0.001). Prolapse height and volume increased little throughout systole in FED versus marked increase in DMD (P<0.001). CONCLUSIONS: Our novel observations show that FED and DMD, although both labeled myxomatous, display considerable physiological phenotypic differences. In DMD, the annular increased size and profoundly abnormal dynamics demonstrate DMD-specific annular degeneration compared with the enlarged but relatively normal FED annulus. DMD does not incur more severe mitral regurgitation, despite larger prolapse and valve redundancy, underscoring potential compensatory role of tissue redundancy of DMD (or aggravating role of tissue paucity of FED) on mitral regurgitation severity.


Assuntos
Ecocardiografia Tridimensional/métodos , Ecocardiografia Transesofagiana/métodos , Insuficiência da Valva Mitral/diagnóstico por imagem , Idoso , Feminino , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/patologia , Insuficiência da Valva Mitral/cirurgia , Fenótipo , Estudos Prospectivos , Índice de Gravidade de Doença
9.
JACC Cardiovasc Imaging ; 7(12): 1185-94, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25440592

RESUMO

OBJECTIVES: The aim of this study was to assess the outcome of isolated tricuspid regurgitation (TR) and the added value of quantitative evaluation of its severity. BACKGROUND: TR is of uncertain clinical outcome due to confounding comorbidities. Isolated TR (without significant comorbidities, structural valve disease, significant pulmonary artery systolic pressure elevation by Doppler, or overt cardiac cause) is of unknown clinical outcome. METHODS: In patients with isolated TR assessed both qualitatively and quantitatively by a proximal isovelocity surface area method, a long-term outcome analysis was conducted. Patients with severe comorbid diseases were excluded. RESULTS: The study involved 353 patients with isolated TR (age 70 years; 33% male; ejection fraction, 63%; all with right ventricular systolic pressure <50 mm Hg). Severe isolated TR was diagnosed in 76 patients (21.5%) qualitatively and 68 patients (19.3%) by quantitative criteria (effective regurgitant orifice [ERO] ≥40 mm(2)). The 10-year survival and cardiac event rates were 63 ± 5% and 29 ± 5%. Severe isolated TR independently predicted higher mortality (adjusted hazard ratio: 1.78 [95% confidence interval (CI): 1.10 to 2.82], p = 0.02 for qualitative definition and 2.67 [95% CI: 1.66 to 4.23] for an ERO ≥40 mm(2), p < 0.0001). The addition of grading by quantitative criteria in nested models eliminated the significance of the qualitative grading and improved the model prediction (p < 0.001 for survival and p = 0.02 for cardiac events). The 10-year survival rate was lower with an ERO ≥40 mm(2) versus <40 mm(2) (38 ± 7% vs. 70 ± 6%; p < 0.0001), independent of all characteristics, right ventricular size or function, comorbidity, or pulmonary pressure (p < 0.0001 for all), and lower than expected in the general population (p < 0.001). Freedom from cardiac events was lower with an ERO ≥40 mm(2) versus <40 mm(2) independently of all characteristics, right ventricular size or function, comorbidity, or pulmonary pressure (p < 0.0001 for all). Cardiac surgery for severe isolated TR was rarely performed (16 ± 5% 5 years after diagnosis). CONCLUSIONS: Isolated TR can be severe and is associated with excess mortality and morbidity, warranting heightened attention to diagnosis and quantitation. Quantitative assessment of TR, particularly ERO measurement, is a powerful independent predictor of outcome, superior to standard qualitative assessment.


Assuntos
Insuficiência da Valva Tricúspide/diagnóstico , Valva Tricúspide/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Intervalo Livre de Doença , Ecocardiografia Doppler , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/mortalidade , Insuficiência da Valva Tricúspide/fisiopatologia , Insuficiência da Valva Tricúspide/terapia
10.
Mayo Clin Proc ; 89(6): 790-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24684783

RESUMO

OBJECTIVE: To assess the diagnostic capability of handheld echocardiography (HHE) compared with transthoracic echocardiography (TTE) performed and evaluated by experienced sonographers and expert echocardiographers. PATIENTS AND METHODS: We conducted a prospective study of adult outpatients undergoing comprehensive TTE between July 9, 2012, and April 3, 2013. Experienced sonographers performed a detailed, standardized examination using a handheld ultrasound device that included 2-dimensional and color Doppler images from standard imaging windows. Images from TTE and HHE were independently interpreted by expert echocardiographers to whom the other study was masked. Agreement between the standard TTE and the HHE reports was analyzed. RESULTS: The study group contained 190 patients (mean ± SD age, 62 ± 17 years; 49% male [n=93]). The κ values were 0.52 for left ventricular (LV) enlargement, 0.52 for right ventricular enlargement, 0.62 for regional wall motion abnormalities, 0.73 for aortic stenosis, and 0.61 for mitral regurgitation. Lin concordance correlation coefficients ranged from 0.89 for LV end-systolic diameter to 0.78 for LV end-diastolic diameter. In 51 patients (27%), echocardiographic findings were discordant between HHE and standard TTE. The most common discordant finding was the presence vs absence of any regional wall motion abnormalities. In discordant cases, HHE tended to underestimate, rather than overestimate, the severity of abnormal findings. CONCLUSION: In experienced hands, HHE shows moderate correlation with standard TTE, but discordant findings were present in 27% of patients. Even when performed and interpreted by experienced operators, HHE should not be used as a surrogate for standard TTE. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01558518.


Assuntos
Ecocardiografia/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Ecocardiografia Doppler/métodos , Ecocardiografia Doppler em Cores , Feminino , Cardiopatias/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos
13.
Harefuah ; 150(2): 131-5, 206, 205, 2011 Feb.
Artigo em Hebraico | MEDLINE | ID: mdl-22164941

RESUMO

Platelet activation and aggregation play a major role in the pathogenesis of acute coronary syndrome (ACS) and thrombotic complications following percutaneous coronary interventions (PCI). Antiplatelet therapy with aspirin (ASA) and/or clopidogrel remains one of the most effective therapies for the treatment of ACS and prevention of thrombotic complications following PCI. Nevertheless, not all patients achieve the desired laboratory and/or clinical effect following antiplatelet therapy. These patients have been termed "aspirin resistant" or "clopidogrel resistant". In recent years, several studies regarding clopidogrel resistance have been conducted, and a number of pharmacological therapies, together with new treatments, have been suggested. This review aims to provide an overview of the epidemiology, prevalence, clinical significance and potential solutions regarding clopidogrel resistance.


Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Inibidores da Agregação Plaquetária/farmacologia , Ticlopidina/análogos & derivados , Síndrome Coronariana Aguda/terapia , Angioplastia Coronária com Balão/efeitos adversos , Angioplastia Coronária com Balão/métodos , Aspirina/farmacologia , Clopidogrel , Resistência a Medicamentos , Humanos , Prevalência , Trombose/etiologia , Trombose/prevenção & controle , Ticlopidina/farmacologia
14.
Brain Res Bull ; 63(1): 25-32, 2004 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-15121236

RESUMO

Prenatal heroin exposure disrupts hippocampal cholinergic synaptic function and related behaviors. Biochemical studies indicate an increase in the number of presynaptic high-affinity choline transporter (HACT) sites, as assessed by [3H]hemicholinium-3 (HC-3) binding. The present study was designed to assess whether this effect involves global upregulation of the transporter, or whether disruption occurs with a specific tempero-spatial distribution. Pregnant mice were given 10mg/kg per day of heroin subcutaneously on gestational days (GD) 9-18. Autoradiographic distribution of HC-3 binding sites was evaluated in the hippocampus of the offspring at postnatal days 15, 25, and 53. These results, suggestive of hippocampal "miswiring," are likely to explain the net impairment of cholinergic synaptic function after prenatal heroin exposure, despite the simultaneous upregulation of both presynaptic cholinergic activity and postsynaptic receptors. Understanding the subregional selectivity of hippocampal defects can lead to the development of strategies that may potentially enable therapeutic interventions to offset or reverse the neurobehavioral defects.


Assuntos
Dependência de Heroína/metabolismo , Heroína/farmacologia , Hipocampo/efeitos dos fármacos , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Transmissão Sináptica/efeitos dos fármacos , Acetilcolina/metabolismo , Animais , Ligação Competitiva/efeitos dos fármacos , Ligação Competitiva/fisiologia , Feminino , Hemicolínio 3/metabolismo , Hemicolínio 3/farmacocinética , Dependência de Heroína/fisiopatologia , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Masculino , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiopatologia , Gravidez , Terminações Pré-Sinápticas/efeitos dos fármacos , Terminações Pré-Sinápticas/metabolismo , Ensaio Radioligante , Membranas Sinápticas/efeitos dos fármacos , Membranas Sinápticas/metabolismo , Transmissão Sináptica/fisiologia
15.
Int J Neuropsychopharmacol ; 6(3): 253-65, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12974992

RESUMO

Opioid drugs act primarily on the opiate receptors; they also exert their effect on other innervations resulting in non-opioidergic behavioural deficits. Similarly, opioid neurobehavioural teratogenicity is attested in numerous behaviours and neural processes which hinder the research on the mechanisms involved. Therefore, in order to be able to ascertain the mechanism we have established an animal (mouse) model for the teratogenicity induced by opioid abuse, which focused on behaviours related to specific brain area and innervation. Diacetylmorphine (heroin) and not morphine was applied because heroin exerts a unique action, distinguished from that of morphine. Pregnant mice were exposed to heroin (10 mg/kg per day) and the offspring were tested for behavioural deficits and biochemical alterations related to the septohippocampal cholinergic innervation. Some studies employing the chick embryo were concomitantly added as a control for the confounding indirect variables. Prenatal exposure to heroin in mice induced global hyperactivation both pre- and post-synaptic along the septohippocampal cholinergic innervation, including basal protein kinase C (PKC) activity accompanied by a desensitization of PKC activity in response to cholinergic agonist. Functionally, the heroin-exposed offspring displayed deficits in hippocampus-related behaviours, suggesting deficits in the net output of the septohippocampal cholinergic innervation. Grafting of cholinergic cells to the impaired hippocampus reversed both pre- and post-synaptic hyperactivity, resensitized PKC activity, and restored the associated behaviours to normality. Consistently, correlation studies point to the relative importance of PKC to the behavioural deficits. The chick model, which dealt with imprinting related to a different brain region, confirmed that the effect of heroin is direct. Taken together with studies by others on the effect of prenatal exposure to opioids on the opioidergic innervation and with what is known on the opioid regulation of the cholinergic innervation, it appears that heroin exerts its neuroteratogenicity by inducing alterations in the opioidergic innervation, which by means of its regulatory action, attenuates the functional output of the cholinergic innervation. In our model, there was hyperactivity mostly of the post-synaptic components of the cholinergic innervation. However, the net cholinergic output is decreased because PKC is desensitized to the effect of the cholinergic agonist, and this is further evidenced by the extensive deficits in the related behaviours.


Assuntos
Entorpecentes/toxicidade , Sistema Nervoso Parassimpático/efeitos dos fármacos , Sistema Nervoso Parassimpático/embriologia , Receptores Opioides/efeitos dos fármacos , Teratogênicos , Animais , Comportamento/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Química Encefálica , Embrião de Galinha , Feminino , Humanos , Gravidez , Ratos
16.
Ann N Y Acad Sci ; 965: 473-8, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12105122

RESUMO

A wide variety of drugs and chemicals elicit neurobehavioral teratogenesis. Surprisingly, however, despite the obvious differences among unrelated compounds, the behavioral outcomes often display striking similarities, such as cognitive and attentional deficits. Recent studies of drugs of abuse (heroin, nicotine, barbiturates) and environmental toxins (environmental tobacco smoke, pesticides, metals) suggest that, regardless of the originating mechanism for perturbation of brain development, disparate neuroteratogens converge downstream on common families of alterations, characterized by changes in the expression and/or activity of the cell-signaling molecules that are essential to neuronal differentiation and synaptic communication. Identification of these common targets may help in the design of pharmacologic interventions that, administered in adulthood, can reverse the impact of exposure to neurobehavioral teratogens.


Assuntos
Transdução de Sinais/fisiologia , Teratogênicos/toxicidade , Animais , Humanos , Transdução de Sinais/efeitos dos fármacos , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia
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