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1.
Eur Heart J Acute Cardiovasc Care ; 10(5): 542-549, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33823539

RESUMO

AIMS: Determining which patients with pericardial effusion require urgent intervention can be challenging. We sought to develop a novel, simple risk prediction score for patients with pericardial effusion. METHODS AND RESULTS: Adult patients admitted through the emergency department (ED) with pericardial effusion were retrospectively evaluated. The overall cohort was divided into a derivation and validation cohort for the generation and validation of a novel risk score using logistic regression. The primary outcome was a pericardial drainage procedure or death attributed to cardiac tamponade within 24 h of ED arrival. Among 195 eligible patients, 102 (52%) experienced the primary outcome. Four variables were selected for the novel score: systolic blood pressure < 100 mmHg (1.5 points), effusion diameter [1-2 cm (0 points), 2-3 cm (1.5 points), >3 cm (2 points)], right ventricular diastolic collapse (2 points), and mitral inflow velocity variation > 25% (1 point). The need for pericardial drainage within 24 h was stratified as low (<2 points), intermediate (2-4 points), or high (≥4 points), which corresponded to risks of 8.1% [95% confidence interval (CI) 3.0-16.8%], 63.8% [95% CI 50.1-76.0%], and 93.7% [95% CI 84.5-98.2%]. The area under the curve of the simplified score was 0.94 for the derivation and 0.91 for the validation cohort. CONCLUSION: Among ED patients with pericardial effusion, a four-variable prediction score consisting of systolic blood pressure, effusion diameter, right ventricular collapse, and mitral inflow velocity variation can accurately predict the need for urgent pericardial drainage. Prospective validation of this novel score is warranted.


Assuntos
Tamponamento Cardíaco , Derrame Pericárdico , Adulto , Tamponamento Cardíaco/diagnóstico , Tamponamento Cardíaco/epidemiologia , Tamponamento Cardíaco/etiologia , Ecocardiografia , Serviço Hospitalar de Emergência , Humanos , Derrame Pericárdico/diagnóstico , Derrame Pericárdico/epidemiologia , Derrame Pericárdico/etiologia , Estudos Retrospectivos
2.
J Am Coll Cardiol ; 70(9): 1135-1144, 2017 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-28838362

RESUMO

BACKGROUND: Appropriate use criteria (AUC) have defined transthoracic echocardiogram (TTE) indications for which there is a clear lack of benefit as rarely appropriate (rA). OBJECTIVES: This study sought to investigate the impact of an AUC-based educational intervention on outpatient TTE ordering by cardiologists and primary care providers. METHODS: The authors conducted a prospective, investigator-blinded, multicenter, randomized controlled trial of an AUC-based educational intervention aimed at reducing rA outpatient TTEs. The study was conducted at 8 hospitals across 2 countries. The authors randomized cardiologists and primary care providers to receive either intervention or control (no intervention). The primary outcome measure was the proportion of rA TTEs. RESULTS: One hundred and ninety-six physicians were randomized, and 179 were included in the analysis. From December 2014 to April 2016, the authors assessed 14,697 TTEs for appropriateness, of which 99% were classifiable using the 2011 AUC. The mean proportion of rA TTEs was significantly lower in the intervention versus the control group (8.8% vs. 10.1%; odds ratio [OR]: 0.75; 95% confidence interval [CI]: 0.57 to 0.99; p = 0.039). In physicians who ordered, on average, at least 1 TTE per month, there was a significantly lower proportion of rA TTEs in the intervention versus the control group (8.6% vs. 11.1%; OR: 0.76; 95% CI: 0.57 to 0.99; p = 0.047). There was no difference in the TTE ordering volume between the intervention and control groups (mean 77.7 ± 89.3 vs. 85.4 ± 111.4; p = 0.83). CONCLUSIONS: An educational intervention reduced the number of rA TTEs ordered by attending physicians in a variety of ambulatory care environments. This may prove to be an effective strategy to improve the use of imaging. (A Multi-Centered Feedback and Education Intervention Designed to Reduce Inappropriate Transthoracic Echocardiograms [Echo WISELY]; NCT02038101).


Assuntos
Serviço Hospitalar de Cardiologia/estatística & dados numéricos , Doenças Cardiovasculares/diagnóstico por imagem , Ecocardiografia/normas , Fidelidade a Diretrizes , Padrões de Prática Médica , Ecocardiografia/estatística & dados numéricos , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Método Simples-Cego
3.
Open Heart ; 3(2): e000411, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27493761

RESUMO

OBJECTIVE: Functional (or secondary) mitral regurgitation (FMR) is associated with greater morbidity and worse outcomes in patients with congestive heart failure (CHF) and cardiomyopathy. The Carillon® Mitral Contour System® is a coronary sinus-based percutaneous therapy to reduce FMR. We evaluated the safety and efficacy of a modified version of the Carillon device in the treatment of patients with cardiomyopathy and FMR. METHODS: 36 patients with CHF, depressed left ventricular function (ejection fraction <40%) and at least moderate FMR underwent the Carillon device implant. RESULTS: There was 1 major adverse event within 30 days-a death (not device related)-occurring 17 days after the implant. Reductions in FMR and improvements in functional class and 6 min walk tests were seen, similar to prior studies. Device fractures in the high strain region of the proximal anchor (seen in prior studies) were not seen in this study. CONCLUSIONS: The modified Carillon device was associated with improvements in clinical and echocardiographic parameters in treating patients with FMR, while successfully addressing the issue of anchor fracture. This version of the Carillon device will be used in a blinded randomised trial of symptomatic patients with FMR.

4.
Am Heart J ; 170(2): 202-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26299215

RESUMO

BACKGROUND: Appropriate use criteria (AUC) for transthoracic echocardiography (TTE) were developed to address concerns regarding inappropriate use of TTE. A previous pilot study suggests that an educational and feedback intervention can reduce inappropriate TTEs ordered by physicians in training. It is unknown if this type of intervention will be effective when targeted at attending level physicians in a variety of clinical settings. AIMS: The aim of this international, multicenter study is to evaluate the hypothesis that an AUC-based educational and feedback intervention will reduce the proportion of inappropriate echocardiograms ordered by attending physicians in the ambulatory environment. METHODS: In an ongoing multicentered, investigator-blinded, randomized controlled trial across Canada and the United States, cardiologists and primary care physicians practicing in the ambulatory setting will be enrolled. The intervention arm will receive (1) a lecture outlining the AUC and most recent available evidence highlighting appropriate use of TTE, (2) access to the American Society of Echocardiography mobile phone app, and (3) individualized feedback reports e-mailed monthly summarizing TTE ordering behavior including information on inappropriate TTEs and brief explanations of the inappropriate designation. The control group will receive no education on TTE appropriate use and order TTEs as usual practice. CONCLUSIONS: The Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly in an education RCT) study is the first multicenter randomized trial of an AUC-based educational intervention. The study will examine whether an education and feedback intervention will reduce the rate of outpatient inappropriate TTEs ordered by attending level cardiologists and primary care physicians (www.clinicaltrials.gov identifier NCT02038101).


Assuntos
Atitude do Pessoal de Saúde , Serviço Hospitalar de Cardiologia/estatística & dados numéricos , Doenças Cardiovasculares/diagnóstico por imagem , Ecocardiografia/normas , Educação Médica/métodos , Guias de Prática Clínica como Assunto , Procedimentos Desnecessários/estatística & dados numéricos , Ecocardiografia/estatística & dados numéricos , Fidelidade a Diretrizes , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Massachusetts , Ontário , Projetos Piloto , Estudos Prospectivos , Método Simples-Cego
5.
Eur J Heart Fail ; 14(8): 931-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22613584

RESUMO

AIMS: Functional mitral regurgitation (FMR) contributes to morbidity and mortality in heart failure (HF) patients. The aim of this study was to determine whether percutaneous mitral annuloplasty could safely and effectively reduce FMR and yield durable long-term clinical benefit. METHODS AND RESULTS: The impact of mitral annuloplasty (Carillon Mitral Contour System) was evaluated in HF patients with at least moderate FMR. Patients in whom the device was placed then acutely recaptured for clinical reasons served as a comparator group. Quantitative measures of FMR, left ventricular (LV) dimensions, New York Heart Association (NYHA) class, 6 min walk distance (6MWD), and quality of life were assessed in both groups up to 12 months. Safety and key functional data were assessed in the implanted cohort up to 24 months. Thirty-six patients received a permanent implant; 17 had the device recaptured. The 30-day major adverse event rate was 1.9%. In contrast to the comparison group, the implanted cohort demonstrated significant reductions in FMR as represented by regurgitant volume [baseline 34.5 ±11.5 mL to 17.4 ±12.4 mL at 12 months (P < 0.001)]. There was a corresponding reduction in LV diastolic volume [baseline 208.5 ±62.0 mL to 178.9 ±48.0 mL at 12 months (P =0.015)] and systolic volume [baseline 151.8 ±57.1 mL to 120.7 ±43.2 mL at 12 months (P =0.015)], compared with progressive LV dilation in the comparator. The 6MWD markedly improved for the implanted patients by 102.5 ±164 m at 12 months (P =0.014) and 131.9 ±80 m at 24 months (P < 0.001). CONCLUSION: Percutaneous reduction of FMR using a coronary sinus approach is associated with reverse LV remodelling. Significant clinical improvements persisted up to 24 months.


Assuntos
Insuficiência Cardíaca/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Anuloplastia da Valva Mitral/métodos , Insuficiência da Valva Mitral/cirurgia , Análise de Variância , Teste de Esforço , Tolerância ao Exercício , Feminino , Indicadores Básicos de Saúde , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/patologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida/psicologia , Fatores de Risco , Volume Sistólico , Fatores de Tempo , Ultrassonografia , Função Ventricular Esquerda
6.
Circulation ; 121(12): 1406-12, 2010 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-20231534

RESUMO

BACKGROUND: Clinical observations of migraine headache symptoms in patients with a patent foramen ovale (PFO), both of which conditions are highly prevalent, have raised the question of a possible pathophysiological relationship. We sought to evaluate the assumption of an association between migraine headaches and the presence of PFO by use of a large case-control study. METHODS AND RESULTS: We conducted a case-control study to assess the prevalence of PFO in subjects with and without migraine. Case subjects were those with a history of migraine (diagnosed by neurologists at a specialty academic headache clinic). Control subjects were healthy volunteers without migraine 1:1 matched on the basis of age and sex with case subjects. Presence of PFO was determined by transthoracic echocardiogram with second harmonic imaging and transcranial Doppler ultrasonography during a standardized procedure of infused agitated saline contrast with or without Valsalva maneuver and a review of the results by experts blinded to case-control status. PFO was considered present if both studies were positive. Odds ratios were calculated with conditional logistic regression in the matched cohort (n=288). In the matched analysis, the prevalence of PFO was similar in case and control subjects (26.4% versus 25.7%; odds ratio 1.04, 95% confidence interval 0.62 to 1.74, P=0.90). There was no difference in PFO prevalence in those with migraine with aura and those without (26.8% versus 26.1%; odds ratio 1.03, 95% confidence interval 0.48 to 2.21, P=0.93). CONCLUSIONS: We found no association between migraine headaches and the presence of PFO in this large case-control study.


Assuntos
Forame Oval Patente/epidemiologia , Transtornos de Enxaqueca/epidemiologia , Adulto , Estudos de Casos e Controles , Eletrocardiografia , Feminino , Forame Oval Patente/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/etiologia , Razão de Chances , Prevalência , Ultrassonografia Doppler Transcraniana
7.
Eur Heart J ; 31(9): 1088-97, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20061327

RESUMO

AIMS: Fabry disease is a rare X-linked deficiency of alpha-galactosidase A (alphagal), which causes glycosphingolipid accumulation. This study analysed the cardiovascular manifestations of a cohort of Fabry patients, and sought to define relationships between disease severity, alphagal activity, and cardiac abnormalities. METHODS AND RESULTS: We prospectively analysed Fabry patients (139 subjects: 92 males and 47 females) undergoing screening for potential enzyme replacement therapy. Baseline echocardiograms, electrocardiograms, and exams were obtained as part of two multinational clinical trials. Cardiovascular symptoms were present in 60.4%. By echocardiography, the mean left ventricular mass index (LVMI) was increased at 165.5 +/- 66.9 g/m(2), and 84.8% of patients displayed concentric left ventricular hypertrophy (LVH). Electrocardiographic LVH was present in >50% of adult subjects. In females, log-corrected plasma alphagal activity was inversely associated with LVMI (r = -0.45, P < 0.040). Males with extremely low alphagal activity and renal disease displayed the most LVH and cardiac symptoms, but LVH was prevalent even in females <20 years old. CONCLUSION: Concentric LVH was the predominant cardiac pathology seen in patients with Fabry disease, and was prevalent in both genders by the third decade of life. Left ventricular mass index was inversely correlated with alphagal activity, but was prevalent even in younger females.


Assuntos
Doença de Fabry/enzimologia , Hipertrofia Ventricular Esquerda/enzimologia , alfa-Galactosidase/metabolismo , Adolescente , Adulto , Idoso , Ecocardiografia , Doença de Fabry/complicações , Feminino , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
8.
Circulation ; 120(4): 326-33, 2009 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-19597051

RESUMO

BACKGROUND: Functional mitral regurgitation (FMR), a well-recognized component of left ventricular remodeling, is associated with increased morbidity and mortality in heart failure patients. Percutaneous mitral annuloplasty has the potential to serve as a therapeutic adjunct to standard medical care. METHODS AND RESULTS: Patients with dilated cardiomyopathy, moderate to severe FMR, an ejection fraction <40%, and a 6-minute walk distance between 150 and 450 m were enrolled in the CARILLON Mitral Annuloplasty Device European Union Study (AMADEUS). Percutaneous mitral annuloplasty was achieved through the coronary sinus with the CARILLON Mitral Contour System. Echocardiographic FMR grade, exercise tolerance, New York Heart Association class, and quality of life were assessed at baseline and 1 and 6 months. Of the 48 patients enrolled in the trial, 30 received the CARILLON device. Eighteen patients did not receive a device because of access issues, insufficient acute FMR reduction, or coronary artery compromise. The major adverse event rate was 13% at 30 days. At 6 months, the degree of FMR reduction among 5 different quantitative echocardiographic measures ranged from 22% to 32%. Six-minute walk distance improved from 307+/-87 m at baseline to 403+/-137 m at 6 months (P<0.001). Quality of life, measured by the Kansas City Cardiomyopathy Questionnaire, improved from 47+/-16 points at baseline to 69+/-15 points at 6 months (P<0.001). CONCLUSIONS: Percutaneous reduction in FMR with a novel coronary sinus-based mitral annuloplasty device is feasible in patients with heart failure, is associated with a low rate of major adverse events, and is associated with improvement in quality of life and exercise tolerance.


Assuntos
Angioplastia Coronária com Balão/instrumentação , Angioplastia Coronária com Balão/métodos , União Europeia , Insuficiência da Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/terapia , Valva Mitral/fisiologia , Idoso , Idoso de 80 Anos ou mais , Estimulação Cardíaca Artificial/métodos , Feminino , Seguimentos , Implante de Prótese de Valva Cardíaca/instrumentação , Implante de Prótese de Valva Cardíaca/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/epidemiologia , Estudos Prospectivos
9.
Am J Physiol Heart Circ Physiol ; 286(3): H1070-5, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14644766

RESUMO

To investigate the role of endothelial nitric oxide synthase (NOS3) in left ventricular (LV) remodeling induced by chronic pressure overload, the impact of transverse aortic constriction (TAC) on LV structure and function was compared in wild-type (WT) and NOS3-deficient (NOS3(-/-)) mice. Before TAC, LV wall thickness, mass, and fractional shortening were similar in the two mouse strains. Twenty-eight days after TAC, both WT and NOS3(-/-) mice had increased LV wall thickness and mass as well as decreased fractional shortening. Although the pressure gradient across the TAC was similar in both strains of mice 28 days after TAC, LV mass and posterior wall thickness were greater in NOS3(-/-) than in WT mice, whereas fractional shortening and the maximum rate of developed LV pressure were less. Diastolic function, as measured by the time constant of isovolumic relaxation and the maximum rate of LV pressure decay, was impaired to a greater extent in NOS3(-/-) than in WT mice. The degree of myocyte hypertrophy and LV fibrosis was greater in NOS3(-/-) than in WT mice at 28 days after TAC. Mortality was greater in NOS3(-/-) than in WT mice 28 days after TAC. Long-term administration of hydralazine normalized the blood pressure and prevented the LV dilation in NOS3(-/-) mice but did not prevent the LV hypertrophy, dysfunction, and fibrosis associated with NOS3 deficiency after TAC. These results suggest that the absence of NOS3 augments LV dysfunction and remodeling in a murine model of chronic pressure overload.


Assuntos
Hipertrofia Ventricular Esquerda/fisiopatologia , Óxido Nítrico Sintase/genética , Disfunção Ventricular Esquerda/fisiopatologia , Animais , Aorta/fisiopatologia , Modelos Animais de Doenças , Ecocardiografia , Fibrose , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Miócitos Cardíacos/patologia , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Tamanho do Órgão , Taxa de Sobrevida , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/patologia
10.
J Am Soc Echocardiogr ; 16(11): 1158-62, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14608287

RESUMO

Murine models are increasingly used to elucidate the molecular mechanisms contributing to left ventricular (LV) remodeling. Epidemiologic and animal studies have suggested that women undergo differing patterns of LV remodeling than men after myocardial infarction (MI). We, therefore, sought to compare LV remodeling after MI in male and female mice. Echocardiography was performed in male and female C57BL6 mice before and serially after MI. Two days after MI, end-diastolic LV internal diameter and shortening fraction were similar in males and females. Between days 2 and 28 after MI, LV internal diameter increased in male mice but remained unchanged in female mice. During this time period, shortening fraction declined in males, but not in females. Posterior wall thickness increased more in females than in males. The size of the MI and the LV mass/body weight were similar between the 2 sexes after MI. Echocardiography showed that after MI, female mice undergo less extensive LV remodeling than males, with less dilation and better preserved LV systolic function 28 days after MI. These sex differences should be taken into account when studying murine cardiac adaptation to MI.


Assuntos
Infarto do Miocárdio/fisiopatologia , Remodelação Ventricular/fisiologia , Animais , Peso Corporal/fisiologia , Modelos Animais de Doenças , Ecocardiografia , Feminino , Seguimentos , Frequência Cardíaca/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/patologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Cardiovasculares , Análise Multivariada , Fatores Sexuais , Volume Sistólico/fisiologia , Sístole/fisiologia , Vasodilatação/fisiologia , Função Ventricular Esquerda/fisiologia
11.
Am J Physiol Heart Circ Physiol ; 285(6): H2524-30, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12907425

RESUMO

Increased nitric oxide (NO) production by inducible NO synthase (NOS2), an obligate homodimer, is implicated in the cardiovascular sequelae of sepsis. We tested the ability of a highly selective NOS2 dimerization inhibitor (BBS-2) to prevent endotoxin-induced systemic hypotension, myocardial dysfunction, and impaired hypoxic pulmonary vasoconstriction (HPV) in mice. Mice were challenged with Escherichia coli endotoxin before treatment with BBS-2 or vehicle. Systemic blood pressure was measured before and 4 and 7 h after endotoxin challenge, and echocardiographic parameters of myocardial function were measured before and 7 h after endotoxin challenge. The pulmonary vasoconstrictor response to left mainstem bronchus occlusion, which is a measure of HPV, was studied 22 h after endotoxin challenge. BBS-2 treatment alone did not alter baseline hemodynamics. BBS-2 treatment blocked NOS2 dimerization and completely inhibited the endotoxin-induced increase of plasma nitrate and nitrite levels. Treatment with BBS-2 after endotoxin administration prevented systemic hypotension and attenuated myocardial dysfunction. BBS-2 also prevented endotoxin-induced impairment of HPV. In contrast, treatment with NG-nitro-l-arginine methyl ester, which is an inhibitor of all three NOS isoforms, prevented the systemic hypotension but further aggravated the myocardial dysfunction associated with endotoxin challenge. Treatment with BBS-2 prevented endotoxin from causing key features of cardiovascular dysfunction in endotoxemic mice. Selective inhibition of NOS2 dimerization with BBS-2, while sparing the activities of other NOS isoforms, may prove to be a useful treatment strategy in sepsis.


Assuntos
Endotoxemia/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Hipotensão/prevenção & controle , Óxido Nítrico Sintase/genética , Animais , Aorta/fisiologia , Dimerização , Endotoxemia/mortalidade , Endotoxemia/fisiopatologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Cardiopatias/tratamento farmacológico , Cardiopatias/mortalidade , Cardiopatias/prevenção & controle , Hipotensão/tratamento farmacológico , Hipotensão/mortalidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Óxido Nítrico Sintase/química , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Nitritos/sangue , Circulação Pulmonar/fisiologia , Vasoconstrição/fisiologia , Vasodilatação/fisiologia
12.
J Biol Chem ; 277(25): 22896-901, 2002 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-11943770

RESUMO

The serine-threonine kinase, Akt, inhibits cardiomyocyte apoptosis acutely both in vitro and in vivo. However, the effects of chronic Akt activation in the heart are unknown. To address this issue, we generated transgenic mice (TG+) with cardiac-specific expression of a constitutively active mutant of Akt (myr-Akt) driven by the myosin heavy chain-alpha promoter. Three TG+ founders (9-19 weeks) died suddenly with massive cardiac dilatation. Two viable TG+ lines (TG564 and TG20) derived from independent founders demonstrated cardiac-specific transgene expression as well as activation of Akt and p70S6 kinase. TG564 (n = 19) showed cardiac hypertrophy with a heart/body weight ratio 2.3-fold greater than littermates (n = 17, p < 0.005). TG20 (n = 18) had less marked cardiac hypertrophy with a heart/body weight ratio 1.6-fold greater than littermates (n = 17, p < 0.005). Isolated TG564 myocytes were also hypertrophic with surface areas 1.7-fold greater than littermates (p < 0.000001). Echocardiograms in both lines demonstrated concentric hypertrophy and preserved systolic function. After ischemia-reperfusion, TG+ had a 50% reduction in infarct size versus TG- (17 +/- 3% versus 34 +/- 4%, p < 0.001). Thus, chronic Akt activation is sufficient to cause a spectrum of phenotypes from moderate cardiac hypertrophy with preserved systolic function and cardioprotection to massive cardiac dilatation and sudden death.


Assuntos
Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/genética , Transgenes , Animais , Western Blotting , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Morte Celular , DNA Complementar/metabolismo , Ecocardiografia , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática , Quinase 3 da Glicogênio Sintase , Hipertrofia , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Proteínas Quinases Ativadas por Mitógeno , Miocárdio/metabolismo , Miocárdio/patologia , Cadeias Pesadas de Miosina/genética , Fenótipo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-akt , Traumatismo por Reperfusão , Proteínas Quinases S6 Ribossômicas/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno
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