Browsing by Author "Greig, Douglas"

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    Ácido úrico: una molécula con acciones paradójicas en la insuficiencia cardiaca
    (2011) Alcaíno, Hernán; Greig, Douglas; Castro Gálvez, Pablo Federico; Verdejo Pinochet, Hugo; Mellado Suazo, Rosemarie; García, Lorena; Díaz Araya, Guillermo; Quiroga Lagos, Clara Rosa; Chiong, Mario; Lavandero, Sergio
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    Cambios en el pronóstico a largo plazo de la hipertensión arterial pulmonar
    (SOC MEDICA SANTIAGO, 2011) Enriquez, Andres; Castro, Pablo; Sepulveda, Pablo; Verdejo, Hugo; Greig, Douglas; Gabrielli, Luigi; Ferrada, Marcela; Lapostol, Carolina
    Background: Pulmonary artery hypertension (PAR) is a progressive disease with high mortality. Major advances had been made in the treatment of this condition during the last decade. Aim: To characterize the clinical evolution and mortality of a cohort of Chilean patients. Material and Methods: Seventeen patients with PAH diagnosed in the last 10 years in two Chilean hospitals were enrolled. Measurements at diagnosis included hemodynamic variables and 6-minute walk test. The patients were followed clinically for 3 years and the observed mortality was compared with that predicted by the prognostic equation proposed by the historic registry of the National Institutes of Health (NIH). Results: The mean age of patients was 45 years and 80% had an idiopathic PAH. The mean median pulmonary artery pressure was 57 +/- 15 mmHg, the cardiac index was 2.4 +/- 0.7 l/min/m(2) and the right atrial pressure was 12 +/- 8 mmHg. The 6-minute walk distance was 348 +/- 98 m. All patients received anticoagulants. Eighty two percent received ambrisentan, 12% received bosentan, 29% received iloprost and 24% sildenafil. At the end of follow-up only 3 patients had died, with an observed survival rate of 88, 82 and 82% at 1, 2 and 3 years, respectively. In contrast, the survival calculated according to the predictive formula of the NIH was 67, 56 and 45%, respectively. Among surviving patients, an improvement in exercise capacity was observed after one year (p < 0.05). Conclusions: The observed survival rate was significantly better than that estimated according to historical data. Furthermore, therapy was associated with an improvement in functional capacity after one year. This prognostic improvement is consistent with data of other contemporary registries published after the NIH Registry. (Rev Med Chile 2011; 139: 327-333).
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    Effects of atorvastatin therapy in heart failure: Oxidative stress, inflammation, endothelial dysfunction and exercise capacity
    (ELSEVIER SCIENCE INC, 2007) Miranda, Rodrigo; Castro, Pablo; Verdejo, Hugo; Greig, Douglas; Alcaino, Hernan; Bustos, Carlos; Vukasovic, Jose Luis; Godoy, Ivan; Diaz Araya, Guillermo; Lavandero, Sergio
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    Ethnic disparities in cardiac transplantation: opportunities to improve long-term outcomes in all cardiac transplant recipients
    (2019) Kobulnik, Jeremy.; Greig, Douglas; Moayedi, Yasbanoo.
    Abstract Ethnic disparities in cardiovascular outcomes have been increasingly recognized in the medical literature. In a recent paper in this journal, Peled et al. provide evidence that Arab Israelis may have worse outcome after cardiac transplant than their Jewish counterparts. This commentary explores possible explanations for the differing outcomes and suggests potential solutions that may improve outcomes for cardiac transplant recipients regardless of ethnicity.Abstract Ethnic disparities in cardiovascular outcomes have been increasingly recognized in the medical literature. In a recent paper in this journal, Peled et al. provide evidence that Arab Israelis may have worse outcome after cardiac transplant than their Jewish counterparts. This commentary explores possible explanations for the differing outcomes and suggests potential solutions that may improve outcomes for cardiac transplant recipients regardless of ethnicity.Abstract Ethnic disparities in cardiovascular outcomes have been increasingly recognized in the medical literature. In a recent paper in this journal, Peled et al. provide evidence that Arab Israelis may have worse outcome after cardiac transplant than their Jewish counterparts. This commentary explores possible explanations for the differing outcomes and suggests potential solutions that may improve outcomes for cardiac transplant recipients regardless of ethnicity.
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    Gln(27)-> Glu beta(2)-Adrenergic Receptor Polymorphism in Heart Failure Patients: Differential Clinical and Oxidative Response to Carvedilol
    (2009) Troncoso, Rodrigo; Moraga, Francisco; Chiong, Mario; Roldán Saelzer, Juan; Bravo, Roberto; Valenzuela Bassi, Rodrigo Andrés; Diaz-Araya, Guillermo; Del Campo, Andrea; Sanhueza, Carlos; Rodriguez, Andrea; Vukasovic, Jose Luis; Mellado Suazo, Rosemarie; Greig, Douglas; Castro Gálvez, Pablo Federico
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    Inequalities in the Access to Advanced Therapy in Heart Failure
    (2015) Greig, Douglas; Olivares, Gabriel
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    Ischemic Electrocardiographic Abnormalities and Prognosis in Decompensated Heart Failure
    (2014) Greig, Douglas; Austin, P.; Zhou, L.; Tu, J.; Pang, P.; Ross, H.; Lee, D.
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    Myocardial lipids and creatine measured by magnetic resonance spectroscopy among patients with heart failure
    (SOC MEDICA SANTIAGO, 2010) Luis Winter, Jose; Castro, Pablo; Meneses, Luis; Chalhub, Monica; Verdejo, Hugo; Greig, Douglas; Gabrielli, Luigi; Chiong, Mario; Concepcion, Roberto; Mellado, Rosemarie; Hernandez, Claudia; Uribe, Sergio; Lavander, Sergio
    Background: Heart failure (HF) is characterized, among other features, by the development of alterations in myocardial energy metabolism, involving a decrease in glucose utilization and increased free fatty acid uptake by cardiomyocytes, associated with decreased deposits of high-energy phosphates (creatine phosphate/ creatine transporter). Magnetic resonance (MR) imaging allows a direct and noninvasive assessment of myocardial metabolites. Aim: To measure myocardial creatine and lipids by MR spectroscopy among patients with HE Material and Methods: Cardiac MR spectroscopy (1.5 Tesla) with Hydrogen antenna and single voxel acquisition was performed in five patients with non-ischemic heart failure, aged 58 +/- 9.7 years, (60% males) and 5 healthy volunteers matched for age and sex. We analyzed the signals of creatine (Cr), lipids (L) and water (W) in the interventricular septum, establishing the water/lipid (W/L) and water/creatine (W/Cr) index to normalize the values obtained. Results: Among patients, left ventricular ejection fraction was 32 +/- 6.9%, 60% were in functional capacity II, 60% had hypertension and one was diabetic. Spectroscopic curves showed a depletion of total Cr, evidenced by the W/Cr index, among patients with heart failure, when compared with healthy controls (1.46 +/- 1.21 and 5.96 +/- 2.25 respectively, p < 0,05). Differences in myocardial lipid content, measured as the W/L index, were not significant (5.06 +/- 2.66 and 1.80 +/- 1.62 respectively, p = 0.08). Conclusions: Among patients with heart failure of non-ischemic etiology, there is a depletion of creatine levels measured by MR spectroscopy. (Rev Med Chile 2010; 138: 1475-1479).
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    Niveles aumentados de estrés oxidativo se asocian a disfunción endotelial periférica y respuesta vascular pulmonar disminuida frente a vasodilatadores en pacientes con hipertensión pulmonar
    (2010) Gabrielli, Luigi; Castro Gálvez, Pablo Federico; Chiong, M.; Alcaíno, H.; Verdejo Pinochet, Hugo; Navarro, M.; Greig, Douglas; Godoy, I.; Toro, B.; Quiroga Lagos, Clara Rosa; Díaz-Araya, G.; Lavandero, S.; García, L.
    ntroducción: La Hipertensión arterial pulmonar (HP) se caracteriza por remodelado vascular y disfunción endotelial. Evidencia experimental muestra que el estrés oxidativo juega un rol importante en la patogénesis de la HP. El rol del estrés oxidativo, su relación con la función endotelial periférica y con la respuesta vascular pulmonar a vasodilatadores en pacientes con HP no está aclarada. Objetivo: evaluar parámetros de estrés oxidativo y función endotelial periférica en pacientes con HP y estudiar su relación con la respuesta vascular pulmonar frente a vasodilatadores. Métodos: estudio transversal. Se incluyeron 14 pacientes con HP y 14 controles pareados por edad y sexo. En todos los sujetos se midieron: niveles plasmáticos de malondialdehido (MDA), superóxi-do dismutasa ligada a endotelio (eSOD) y xantino oxidasa (eXO). Vasodilatación dependiente de endotelio mediada por flujo en arteria braquial fue usada como marcador de función endotelial (FDD). Función ventricular derecha y reactividad del lecho vascular pulmonar frente a iloprost inhalado fueron evaluadas ecocardiográficamente en los pacientes con HP Resultados: Los pacientes con HP presentaron FDD disminuida versus los controles (2,8 ± 0,6 vs 10,7% ± 0,6, p< 0,01). Niveles de MDA y eXO aumentados (0,61 ± 0,17 vs 0,34 ± 0,15μM, p<0,01 y 0,039 ± 0,005 vs 0,034 ± 0,004 U/mL1, p=0,02 respectivamente) y actividad de eSOD disminuida (235,55 ± 23 vs 461,41 ± 33 ABC, p<0,01). Iloprost mejora significativamente el gasto cardíaco derecho y disminuye la resistencia vascular pulmonar en los pacientes con HP y este cambio se correlaciona con la actividad de eSOD (Rho: 0,61, p<0,01) y FDD (Rho: 0,63, p=0,01). Conclusiones: Pacientes con HP presentan parámetros de estrés oxidativo elevados y disfunción endotelial periférica La respuesta hemodinámica frente al uso de Iloprost se correlaciona con estos parámetros sugiriendo un rol en la HP cuyo valor clínico deberá ser evaluado.
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    Optimal length of triple therapy for H pylori eradication in a population with high prevalence of infection in Chile
    (BAISHIDENG PUBLISHING GROUP INC, 2007) Riquelme, Arnoldo; Soza, Alejandro; Pedreros, Cesar; Bustamante, Andrea; Valenzuela, Felipe; Otarola, Francisco; Abbott, Eduardo; Arellano, Marco; Medina, Brenda; Pattillo, Alejandro; Greig, Douglas; Arrese, Marco; Rollan, Antonio
    AIM: To compare the efficacy of 7-d versus 14-d triple therapy for the treatment of H pylori infection in Chile, with a prevalence of 73% in general population. METHODS: H pylori-infected patients diagnosed by rapid urease test, with non-ulcer dyspepsia or peptic ulcer disease were randomized to receive omeprazole 20 mg bid, amoxicillin 1 g bid, and clarithromycin 500 mg bid for 7 (OAC7) or 14 (OAC14) d. Primary outcome was eradication rate 6 wk after the treatment. Subgroup analysis was carried out considering the eradication rate among patients with or without peptic ulcer disease and eradication rate among smokers or non-smokers.
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    Pleiotropic effects of atorvastatin in heart failure : role in oxidative stress, inflammation, endothelial function, and exercise capacity
    (2008) Castro Gálvez, Pablo Federico; Miranda, Rodrigo; Verdejo Pinochet, Hugo; Greig, Douglas; Gabrielli, Luigi; Alcaíno, Hernán; Chiong, Mario; Bustos, Carlos; García, Lorena; Mellado Suazo, Rosemarie; Vukasovic, José Luis; Godoy J., Iván; Lavandero, Sergio
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    Relationship between mechanical and metabolic dyssynchrony with left bundle branch block: Evaluation by 18-fluorodeoxyglucose positron emission tomography in patients with non-ischemic heart failure
    (ELSEVIER SCIENCE INC, 2012) Castro, Pablo; Luis Winter, Jose; Verdejo, Hugo; Orellana, Pilar; Carlos Quintana, Juan; Greig, Douglas; Enriquez, Andres; Sepulveda, Luis; Concepcion, Roberto; Sepulveda, Pablo; Rossel, Victor; Chiong, Mario; Garcia, Lorena; Lavandero, Sergio
    BACKGROUND: Ventricular dyssynchrony is a common finding in patients with heart failure (HF), especially in the presence of conduction delays. The loss of ventricular synchrony leads to progressive impairment of contractile function, which may be explained in part by segmental abnormalities of myocardial metabolism. However, the association of these metabolic disarrangements with parameters of ventricular dyssynchrony and electrocardiography (ECG) findings has not yet been studied.
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    Serum uric acid correlates with extracellular superoxide dismutase activity in patients with chronic heart failure
    (2008) Alcaíno, Hernán; Greig, Douglas; Chiong, Mario; Verdejo Pinochet, Hugo; Miranda, Rodrigo; Concepcion, Roberto; Vukasovic, José Luis; Díaz-Araya, Guillermo; Mellado Suazo, Rosemarie; García, Lorena; Salas, Daniela; González, Leticia; Godoy J., Iván; Castro Gálvez, Pablo Federico; Lavandero, Sergio
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    Xanthine-oxidase inhibitors and statins in chronic heart failure: Effects on vascular and functional parameters
    (ELSEVIER SCIENCE INC, 2011) Greig, Douglas; Alcaino, Hernan; Castro, Pablo F.; Garcia, Lorena; Verdejo, Hugo E.; Navarro, Mario; Lopez, Rafael; Mellado, Rosemarie; Tapia, Fabiola; Gabrielli, Luigi A.; Nogerol, Camilo; Chiong, Mario; Godoy, Ivan; Lavandero, Sergio
    BACKGROUND: Increased oxidative stress in heart failure (HF) leads to inflammation and endothelial dysfunction (ED). Both statins and allopurinol have known anti-oxidant properties, but their utility in HF has not been fully assessed.