Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Clin Res Cardiol ; 109(4): 498-507, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31368000

RESUMEN

AIM: The aim of this study was to assess PCWP with passive leg-lifting (PLL) and exercise, in two groups of patients presenting with normal left ventricular ejection fraction (LVEF); one group with elevated NT-proBNP (eBNP), and one with normal NT-proBNP (nBNP) plasma concentration. METHODS AND RESULTS: Fifty-one patients with eBNP (NT-proBNP ≥ 125 ng/l) and LVEF > 50%, were investigated and compared with 34 patients with nBNP (NT-proBNP < 125 ng/l) and LVEF > 50%. Both groups underwent right heart catheterization (RHC) at rest, PLL and exercise. From RHC, mean pulmonary arterial pressure (mPAP), cardiac output (CO), and PCWP were measured. All nBNP patients had PCWP < 15 mmHg at rest, and a PCWP of < 25 mmHg with PLL and during exercise. Patients with eBNP had higher (p < 0.01) resting mPAP, PCWP, and mPAP/CO. These values increased with exercise; however, CO increased less in comparison with nBNP patients (p = 0.001). 20% of patients with eBNP had a PCWP > 15 mmHg at rest, this percentage increased to 47% with PLL and 41% had a PCWP > 25 mmHg during exercise. Of those with PCWP > 25 mmHg during exercise, 91% had a PCWP > 15 mmHg with PLL. A PCWP > 15 mmHg on PLL had a 91% sensitivity and 92% specificity in predicting exercise-induced PCWP of > 25 mmHg. CONCLUSION: In patients presenting with eBNP, PLL can predict which patients will develop elevated PCWP with exercise. These findings highlight the role of stress assessment.


Asunto(s)
Prueba de Esfuerzo , Insuficiencia Cardíaca/diagnóstico , Péptido Natriurético Encefálico/sangre , Fragmentos de Péptidos/sangre , Presión Esfenoidal Pulmonar , Función Ventricular Izquierda , Presión Ventricular , Adulto , Anciano , Ciclismo , Biomarcadores/sangre , Femenino , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Regulación hacia Arriba
2.
Clin Res Cardiol ; 106(12): 960-973, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28795299

RESUMEN

INTRODUCTION: Despite that heart rate (HR) control is one of the guideline-recommended treatment goals for heart failure (HF) patients, implementation has been painstakingly slow. Therefore, it would be important to identify patients who have not yet achieved their target heart rates and assess possible underlying reasons as to why the target rates are not met. MATERIALS AND METHODS: The survey of HR in patients with HF in Sweden (HR-HF survey) is an investigator-initiated, prospective, multicenter, observational longitudinal study designed to investigate the state of the art in the control of HR in HF and to explore potential underlying mechanisms for suboptimal HR control with focus on awareness of and adherence to guidelines for HR control among physicians who focus on the contributing role of beta-blockers (BBs). RESULTS: In 734 HF patients the mean HR was 68 ± 12 beats per minute (bpm) (37.2% of the patients had a HR >70 bpm). Patients with HF with reduced ejection fraction (HFrEF) (n = 425) had the highest HR (70 ± 13 bpm, with 42% >70 bpm), followed by HF with preserved ejection fraction and HF with mid-range ejection fraction. Atrial fibrillation, irrespective of HF type, had higher HR than sinus rhythm. A similar pattern was observed with BB treatment. Moreover, non-achievement of the recommended target HR (<70 bpm) in HFrEF and sinus rhythm was unrelated to age, sex, cardiovascular risk factors, cardiovascular diseases, and comorbidities, but was related to EF and the clinical decision of the physician. Approximately 50% of the physicians considered a HR of >70 bpm optimal and an equal number considered a HR of >70 bpm too high, but without recommending further action. Furthermore, suboptimal HR control cannot be attributed to the use of BBs because there was neither a difference in use of BBs nor an interaction with BBs for HR >70 bpm compared with HR <70 bpm. CONCLUSION: Suboptimal control of HR was noted in HFrEF with sinus rhythm, which appeared to be attributable to physician decision making rather than to the use of BBs. Therefore, our results underline the need for greater attention to HR control in patients with HFrEF and sinus rhythm and thus a potential for improved HF care.


Asunto(s)
Antagonistas de Receptores Adrenérgicos beta 1/uso terapéutico , Terapia de Resincronización Cardíaca/métodos , Adhesión a Directriz , Insuficiencia Cardíaca/terapia , Frecuencia Cardíaca/fisiología , Vigilancia de la Población/métodos , Volumen Sistólico/fisiología , Anciano , Electrocardiografía , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento
3.
Ultrasound Obstet Gynecol ; 50(1): 93-99, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27256927

RESUMEN

OBJECTIVE: Pre-eclampsia (PE) is associated with an increased risk of cardiovascular disease later in life. In cases with PE there is a substantial increase in levels of the antiangiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased levels of the proangiogenic factor placental growth factor (PlGF). Elevated levels of sFlt-1 are also found in individuals with cardiovascular disease. The aims of this study were to assess levels of sFlt-1, PlGF and the sFlt-1/PlGF ratio and their correlation with signs of arterial aging by measuring the common carotid artery (CCA) intima and media thicknesses and their ratio (I/M ratio) in women with and without PE. METHODS: Serum sFlt-1 and PlGF levels were measured using commercially available enzyme-linked immunosorbent assay kits, and CCA intima and media thicknesses were estimated using high-frequency (22-MHz) ultrasonography in 55 women at PE diagnosis and in 64 women with normal pregnancy at a similar gestational age, with reassessment at 1 year postpartum. RESULTS: During pregnancy, higher levels of sFlt-1, lower levels of PlGF, a thicker intima, a thinner media and a higher I/M ratio of the CCA were found in women with PE vs controls (all P < 0.0001). Further, sFlt-1 and the sFlt-1/PlGF ratio were positively correlated with intima thickness and I/M ratio (all P < 0.0001). At 1 year postpartum, levels of sFlt-1 and the sFlt-1/PlGF ratio had decreased in both groups; however, their levels in the PE group were still higher than in the controls (P = 0.001 and < 0.0001, respectively). Levels of sFlt-1 and the sFlt-1/PlGF ratio remained positively correlated with intima thickness and I/M ratio at 1 year postpartum. CONCLUSIONS: Higher sFlt-1 levels and sFlt-1/PlGF ratio in women with PE were positively associated with signs of arterial aging during pregnancy. At 1 year postpartum, sFlt-1 levels and the sFlt-1/PlGF ratio were still higher in the PE group and were associated with the degree of arterial aging. © 2016 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Biomarcadores/sangre , Arteria Carótida Común/diagnóstico por imagen , Preeclampsia/diagnóstico por imagen , Ultrasonografía Prenatal , Adulto , Envejecimiento , Arteria Carótida Común/fisiopatología , Estudios de Casos y Controles , Femenino , Humanos , Factor de Crecimiento Placentario/sangre , Preeclampsia/sangre , Preeclampsia/fisiopatología , Embarazo , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre
4.
Int J Cardiol ; 199: 337-41, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26241640

RESUMEN

INTRODUCTION: Heart failure places a significant economic burden on health care. Acute heart failure requires hospitalization and often frequent re-hospitalization in expensive wards where vasoactive rescue therapy is often added on top of standard medications. In these lean times, there is a growing need for cost-effective therapeutic options that supply superior support and in addition shorten the length of stay in hospital and reduce re-hospitalization rates. The inodilator levosimendan represents the latest addition to the vasoactive treatments of acute heart failure patients, and it appears to meet these expectations. Our aim was to answer the question whether the treatment efficacy of levosimendan - when selected as therapy for patients hospitalized for acute heart failure - brings savings to hospitals in various European countries representing different economies. METHODS AND RESULTS: We took a conservative approach and selected some a fortiori arguments to simplify the calculations. We selected seven European countries to represent different economies: Italy, Spain, Greece, Germany, Sweden, Finland and Israel. Data on the costs of medications and on the cost per day were collected and fed in a simple algorithm to detect savings. These saving varied from country to country, from a minimum of €0.50 in Germany to a maximum of €354.64 in Sweden. CONCLUSIONS: The use of levosimendan as a therapy for patients hospitalized for acute heart failure provides a net saving to hospitals driven by a reduction in the length of hospital stay. This finding is true in each of the countries considered in this study.


Asunto(s)
Cardiotónicos/economía , Cardiotónicos/farmacología , Insuficiencia Cardíaca/tratamiento farmacológico , Hidrazonas/economía , Hidrazonas/farmacología , Piridazinas/economía , Piridazinas/farmacología , Enfermedad Aguda , Algoritmos , Cardiología , Análisis Costo-Beneficio , Economía Farmacéutica , Europa (Continente)/epidemiología , Insuficiencia Cardíaca/economía , Insuficiencia Cardíaca/mortalidad , Hospitalización/economía , Humanos , Tiempo de Internación/economía , Modelos Económicos , Mortalidad , Calidad de Vida , Simendán
5.
Int J Cardiol ; 174(2): 360-7, 2014 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-24780540

RESUMEN

BACKGROUND: The intravenous inodilator levosimendan was developed for the treatment of patients with acutely decompensated heart failure. In the last decade scientific and clinical interest has arisen for its repetitive or intermittent use in patients with advanced chronic, but not necessarily acutely decompensated, heart failure. Recent studies have suggested long-lasting favourable effects of levosimendan when administered repetitively, in terms of haemodynamic parameters, neurohormonal and inflammatory markers, and clinical outcomes. The existing data, however, requires further exploration to allow for definitive conclusions on the safety and clinical efficacy of repetitive use of levosimendan. METHODS AND RESULTS: A panel of 30 experts from 15 countries convened to review and discuss the existing data, and agreed on the patient groups that can be considered to potentially benefit from intermittent treatment with levosimendan. The panel gave recommendations regarding patient dosing and monitoring, derived from the available evidence and from clinical experience. CONCLUSIONS: The current data suggest that in selected patients and support out-of-hospital care, intermittent/repetitive levosimendan can be used in advanced heart failure to maintain patient stability. Further studies are needed to focus on morbidity and mortality outcomes, dosing intervals, and patient monitoring. Recommendations for the design of further clinical studies are made.


Asunto(s)
Insuficiencia Cardíaca/tratamiento farmacológico , Hidrazonas/administración & dosificación , Piridazinas/administración & dosificación , Vasodilatadores/administración & dosificación , Enfermedad Crónica , Humanos , Guías de Práctica Clínica como Asunto , Índice de Severidad de la Enfermedad , Simendán
6.
Acta Physiol (Oxf) ; 199(1): 1-9, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20028345

RESUMEN

AIM: 'Pre-treatment' with short repetitive periods of ischaemia (ischaemic preconditioning) has proved to be a powerful mechanism for modification of the extent of myocardial damage following acute coronary artery occlusion. The exact mechanism of protection induced by ischaemic preconditioning is not known. We herewith put forward a contributing component for protection with preconditioning involving a shift in the adenylate kinase (AK) equilibrium reaction in favour of adenosine triphosphate (ATP) formation. METHODS: A coronary artery was occluded in anaesthetized thoracotomized pigs to induce ischaemic preconditioning as well as a longer period of ischaemia. Microdialysis probes were inserted in ischaemic and control myocardium and were infused with (14)C- adenosine with two different specific activities. (14)C-lactate was identified and measured in the effluent. RESULTS: (14)C-adenosine was taken up by non-preconditioned and preconditioned myocardium during ischaemia. Significantly increased levels of (14)C-lactate were recovered in preconditioned myocardium. (14)C-adenosine with high specific activity resulted in a specific activity of lactate that was 2.7 times higher than that of lactate after administration of (14)C-adenosine with low specific activity. Mass spectrography verified the identity of (14)C-lactate. CONCLUSIONS: Preconditioning up-regulates a new metabolic pathway (starting with 5'-nucleotidase and ending up with lactate) resulting in ATP formation in the micromolar range on top of another effect terminating in a useful shift in the AK equilibrium reaction in favour of ATP generation in the millimolar range. Although the up-regulation of the purine nucleoside phosphorylase pathway is clearly demonstrated, its biological relevance remains to be proved.


Asunto(s)
Adenosina/metabolismo , Precondicionamiento Isquémico Miocárdico , Isquemia Miocárdica , Miocardio/metabolismo , 5'-Nucleotidasa/metabolismo , Adenosina/química , Adenosina Trifosfato/metabolismo , Animales , Femenino , Humanos , Ácido Láctico/metabolismo , Microdiálisis/métodos , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patología , Porcinos
7.
Eur J Heart Fail ; 10(9): 869-77, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18684664

RESUMEN

BACKGROUND: The aim of this study was to investigate the cost-effectiveness of cardiac resynchronization therapy (CRT) in Denmark, Finland and Sweden. The analysis was based on the CARE-HF trial, a randomised clinical trial investigating the efficacy of adding CRT (n=409) to optimal pharmacological treatment (n=404) in patients with moderate to severe heart failure with markers of cardiac dyssynchrony. The average follow-up time was 29.4 months. METHODS: The health effects were measured in terms of quality-adjusted life years (QALYs) gained. Data on health care resource consumption from CARE-HF was combined with costs for CRT implantation and hospitalisation from university hospitals in Denmark, Finland and Sweden. Calculations were based on patients' expected life time. The expected device lifetime (6 years) was used for CRT, and no additional gains in clinical effects were assumed after the 6 years. RESULTS: The cost-effectiveness ratio per QALY gained was 4800 euros in Denmark, 3600 euros in Finland and 6700 euros in Sweden. The 95% confidence intervals for the cost per QALY gained varied between a lower limit of 1169 euros in Finland to an upper limit of 17,482 euros in Sweden. These values were all below the threshold for being cost-effective in Denmark, Finland and Sweden. CONCLUSIONS: The study indicates that CRT is a cost-effective treatment in Scandinavian health care settings compared to traditional pharmacological therapy and can therefore be recommended for routine use in patients with moderate to severe heart failure and markers of dyssynchrony.


Asunto(s)
Estimulación Cardíaca Artificial/economía , Análisis Costo-Beneficio/economía , Insuficiencia Cardíaca/economía , Insuficiencia Cardíaca/terapia , Dinamarca , Femenino , Finlandia , Recursos en Salud/estadística & datos numéricos , Humanos , Masculino , Años de Vida Ajustados por Calidad de Vida , Análisis de Supervivencia , Suecia , Resultado del Tratamiento
8.
J Interferon Cytokine Res ; 26(9): 661-7, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16978070

RESUMEN

To evaluate whether etanercept, a tumor necrosis factor (TNF)-blocking agent, may counteract hemodynamic deterioration in endotoxemic shock, we designed a prospective, randomized placebo-controlled trial with parallel groups, consisting of 13 pigs aged 10-14 weeks receiving general anesthesia. Five pigs were given 25 mg of etanercept, 1 h before the start of a 4-h continuous infusion of endotoxin. Another 5 pigs were given the corresponding volume of saline, 1 h before the start of a 4-h continuous infusion of endotoxin. Three pigs were given 25 mg of etanercept, 1 hr before the start of a 4-h continuous infusion of saline. At 1 h of endotoxemia, mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance index (PVRI) increased identically in both groups of pigs receiving endotoxin. Thereafter, two distinct different patterns in hemodynamics were observed. TNF-blocked pigs showed significantly lower MPAP and PVRI compared to controls. In the etanercept-treated endotoxemic pigs, Doppler analysis of the diastolic mitral inflow demonstrated a significantly increased E/A-ratio (early mitral wave inflow was divided by the atrial wave) at 2 h. The TNFblocking agent etanercept normalized two hemodynamic features of endotoxin-induced septic shock in pigs: (1) the sustained pulmonary hypertension and (2) diastolic dysfunction.


Asunto(s)
Endotoxinas/farmacología , Hipertensión Pulmonar , Inmunoglobulina G/uso terapéutico , Inmunosupresores/uso terapéutico , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Presión Sanguínea/fisiología , Ecocardiografía Doppler , Etanercept , Humanos , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/tratamiento farmacológico , Placebos , Estudios Prospectivos , Distribución Aleatoria , Porcinos , Resistencia Vascular/fisiología
9.
Amino Acids ; 27(1): 107-11, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15309579

RESUMEN

The microdialysis (MD) technique allows for continuous in vivo monitoring of dynamic changes in the interstitial levels of energy-related metabolites. The release of taurine from the myocyte has been suggested as a marker of ischemic injury. The relationship between (interstitial) taurine release and the degree of myocardial ischemic injury was evaluated following a 40 min long ischemia in a porcine heart-infarct-model. Different protocols of ischemia and reperfusion were used in order to achieve a graded level of myocardial injury. Both interstitial peak levels and the area under curve of taurine obtained during ischemia and reperfusion correlated with the degree of ischemic injury (assessed by developed infarct size estimation). The release of taurine in the myocardium measured by the MD-technique correlated with the degree of ischemic injury during ongoing ischemic insult. Hence, taurine determination in the MD-setting represents a powerful tool to follow the development of myocardial ischemic injury over time.


Asunto(s)
Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patología , Reperfusión Miocárdica , Miocardio/metabolismo , Taurina/biosíntesis , Animales , Área Bajo la Curva , Isquemia , Infarto del Miocardio , Daño por Reperfusión , Porcinos , Taurina/química , Taurina/metabolismo , Factores de Tiempo
10.
Acta Physiol Scand ; 179(1): 61-5, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12940939

RESUMEN

OBJECTIVES: The validity of the microdialysis technique for experimental in vivo studies of myocardial energy metabolism is not known. To address this question interstitial levels of energy-related metabolites (lactate, adenosine, inosine and hypoxanthine) obtained by the microdialysis technique were compared with corresponding metabolites from myocardial biopsies at given intervals in a porcine heart model using different protocols of ischaemia and reperfusion. METHODS: In an open chest porcine heart model, interstitial levels of energy-related metabolites were monitored using the microdialysis technique. All animals (n = 23) were subjected to 120-min pretreatment followed by 40 min of regional ischaemia and 120 min of reperfusion. Tissue biopsies were obtained in the beginning, middle and at the end of the 40-min ischaemic period and at the end of the reperfusion period. Pretreatment consisted of either rest (group 1, n = 7), or rest for 90 min and one ischaemia/reperfusion (10 + 20 min) cycle (group 2, n = 9), or four ischaemia/reperfusion cycles (10 + 20 min each) (group 3, n = 7). RESULTS: Interstitial levels of energy-related metabolites monitored by the microdialysis technique correlated with tissue biopsy levels of lactate (r = 0.90, P < 0.001), adenosine (r = 0.89, P < 0.001), inosine (r = 0.88, P < 0.001) and hypoxanthine (r = 0.91, P < 0.001), respectively, which were obtained by tissue biopsies at given time intervals. These significant correlations were valid regardless of the functional state of the myocardium. CONCLUSION: We observed significant correlations between microdialysis probe levels and tissue biopsy levels of energy-related metabolites in both ischaemic and non-ischaemic tissue. These data assess the validity of the microdialysis technique (in the current setting) for studying dynamic changes of myocardial energy metabolism.


Asunto(s)
Metabolismo Energético , Microdiálisis/métodos , Miocardio/metabolismo , Adenosina/metabolismo , Animales , Biopsia , Hipoxantina/metabolismo , Inosina/metabolismo , Ácido Láctico/metabolismo , Isquemia Miocárdica/metabolismo , Reperfusión Miocárdica , Reproducibilidad de los Resultados , Porcinos
11.
Acta Physiol Scand ; 178(2): 129-37, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12780387

RESUMEN

AIMS AND METHODS: Recently it was suggested that ischaemic preconditioning (IP) protects the myocardium in a graded pattern as assessed by myocardial infarct size estimation. Using tissue biopsies we investigated the impact of the proposed graded pattern of protection on myocardial energy state in an open-chest porcine model of IP with either one (1xIP) or four (4xIP) episodes of preconditioning. Furthermore, we evaluated the relationship between interstitial energy-related metabolite levels obtained by the microdialysis technique and the degree of subsequent ischaemic insult. RESULTS: During the long ischaemia the difference between pre-ischaemic and post-ischaemic total adenylate pools and the sum of adenylate breakdown products (adenosine, inosine and hypoxanthine) as well as tissue lactate levels appeared as follows: non-IP > 1xIP > 4xIP (P < 0.05). Moreover interstitial peak levels of lactate, hypoxanthine and taurine displayed a graded pattern analogous to the development of ischaemic damage, where non-IP > 1xIP > 4xIP. CONCLUSIONS: We present for the first time concordant energy metabolic and morphometric data in support of IP being a stepwise phenomenon for protection of the ischaemic myocardium. Furthermore, IP resulted in proportionally higher levels of hypoxanthine (relative to inosine) in the ischaemic myocardium, suggesting a different handling of adenine nucleotide breakdown products in the IP myocardium.


Asunto(s)
Metabolismo Energético/fisiología , Precondicionamiento Isquémico Miocárdico/métodos , Miocardio/metabolismo , Adenosina Difosfato/análisis , Adenosina Difosfato/metabolismo , Adenosina Monofosfato/análisis , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/análisis , Adenosina Trifosfato/metabolismo , Animales , Presión Sanguínea/fisiología , Gasto Cardíaco/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Lactatos/análisis , Masculino , Microdiálisis/métodos , Miocardio/patología
12.
Radiology ; 221(3): 822-6, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11719685

RESUMEN

The authors evaluated the feasibility of combining single-shot T2-weighted turbo spin-echo magnetic resonance (MR) imaging and first-pass myocardial perfusion MR imaging with an intravascular ultrasmall superparamagnetic iron oxide (USPIO) contrast agent, NC100150 Injection (3 mg of iron per kilogram of body weight). Eight patients with coronary vessel disease underwent T2-weighted turbo spin-echo MR imaging (in-plane resolution, 1-2 mm) during the first pass of the USPIO contrast agent. The mean decrease in signal intensity in myocardium perfused by a nonstenotic coronary artery was 59% +/- 13 (SD) (P < .012) This method is feasible for imaging of myocardial perfusion.


Asunto(s)
Medios de Contraste/administración & dosificación , Circulación Coronaria , Enfermedad Coronaria/diagnóstico , Aumento de la Imagen , Hierro , Óxidos , Adulto , Anciano , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Vasos Coronarios/patología , Dextranos , Femenino , Óxido Ferrosoférrico , Humanos , Inyecciones Intravenosas , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética , Nanopartículas de Magnetita , Masculino , Persona de Mediana Edad
13.
Acta Physiol Scand ; 173(2): 185-94, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11683676

RESUMEN

During pre-conditioning the interstitial concentration of adenosine, in contrast to lactate, presents a die-away curve-pattern for every successive episode of ischaemia. This die-away pattern might not necessarily be attributed to diminished adenosine production. The present study was undertaken to investigate whether pre-conditioning alters the metabolic turnover of adenosine as observed by the lactate production during ischaemia. Interstitial levels of metabolites in pre-conditioned (n=21) and non-preconditioned (n=21) porcine hearts were monitored with microdialysis probes inserted in both ischaemic and non-ischaemic tissue in an open chest heart model. Three subgroups perturbated with either plain microdialysis buffer (control), buffer containing adenosine (375 microM), or buffer containing deoxyadenosine (375 microM) were studied. All animals were subjected to 90 min of equilibrium microdialysis before 40 min of regional myocardial ischaemia and 120 min of reperfusion. Pre-conditioning consisted of four repetitive episodes of 10 min of ischaemia and 20 min of reperfusion. Significantly higher levels of inosine and lactate were found in the ischaemic tissue of the pre-conditioned subgroup receiving adenosine (P < 0.05) compared with the other two subgroups receiving deoxyadenosine and plain buffer, respectively. This difference was only valid for pre-conditioned ischaemic myocardium, and hence equal amounts of inosine and lactate were produced in the non-preconditioned ischaemic myocardium regardless of the presence of adenosine or deoxyadenosine. In the non-ischaemic myocardium baseline levels of metabolites were measured in all subgroups. Pre-conditioning favoured degradation of exogenous adenosine to inosine successively ending up in enhanced lactate production. This was probably because of the involvement of the hexose monophosphate pathway in the pre-conditioned ischaemic myocardium. This route may therefore be supplementary in energy metabolism as a metabolic flow can be started by adenosine ending up in lactate without initial adenosine 5'-triphosphate (ATP) investment. Utilization of adenosine in this way may also explain the successive die-away pattern of adenosine seen in consecutive pre-conditioning cycles.


Asunto(s)
Adenosina/farmacocinética , Precondicionamiento Isquémico Miocárdico , Isquemia Miocárdica/metabolismo , Animales , Desoxiadenosinas/farmacocinética , Femenino , Glucólisis/fisiología , Inosina/metabolismo , Ácido Láctico/metabolismo , Masculino , Microdiálisis , Miocardio/metabolismo , Vía de Pentosa Fosfato/fisiología , Porcinos
14.
Acta Physiol Scand ; 171(2): 129-43, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11350273

RESUMEN

In the clinical setting great efforts have been made with contradictory results to operate upon acutely myocardial ischaemic patients. The reasons for the absence of clear-cut results are not well understood nor are they scientifically explored. To resolve this problem further, we attempted to design an experimental in vivo model to mimic acute myocardial ischaemia followed by extracorporeal circulation (ECC) and reperfusion. One of the main targets of our protocol was monitoring of myocardial energy metabolism by microdialysis (MCD) during the periods of coronary occlusion (60 min), hypothermic (30 degrees C) ECC and cardioplegia (45 min), followed by reperfusion with (30 min) and without (60 min) ECC. In eight anaesthetized, open-chest pigs, myocardial lactate, pyruvate, adenosine, taurine, inosine, hypoxanthine and guanosine were sampled with MCD in both ischaemic and non-ischaemic areas. Myocardial area at risk and infarct size were quantified with the modified topographical evaluation methods. The principal finding with this experimental setup was a biphasic release pattern of lactate, adenosine, taurine, inosine, hypoxanthine and guanosine from ischaemic myocardium. Lactate levels were equally high in reperfused ischaemic and non-ischaemic myocardial tissue. Pyruvate demonstrated consistently higher values in non-ischaemic myocardium throughout the experiment. A pattern was discernible, lactate being a marker of compromised cell energy metabolism, and taurine being a marker of disturbed cell integrity. Of special interest was the increased level of pyruvate in microdialysates of non-ischaemic myocardium as compared with its ischaemic counterpart. In conclusion, we found disturbances in energy metabolism and cell integrity not only in ischaemic but also in non-ischaemic tissue during reperfusion implying that non-ischaemic myocardium demonstrated an unexpected accumulation of lactate and pyruvate. These new findings could at least partly be explicatory to the increased risk of heart surgery in connection with acute myocardial infarction.


Asunto(s)
Metabolismo Energético , Circulación Extracorporea , Infarto del Miocardio/metabolismo , Daño por Reperfusión/metabolismo , Adenosina/análisis , Animales , Cromatografía Líquida de Alta Presión , Soluciones para Diálisis/química , Modelos Animales de Enfermedad , Guanina/análisis , Paro Cardíaco Inducido , Hipoxantina/análisis , Inosina/análisis , Ácido Láctico/análisis , Microdiálisis , Infarto del Miocardio/etiología , Infarto del Miocardio/patología , Miocardio/metabolismo , Ácido Pirúvico/análisis , Porcinos , Taurina/análisis
15.
Eur J Pharmacol ; 411(1-2): 143-154, 2001 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-11137869

RESUMEN

We measured with the microdialysis technique energy-related metabolites in ischemic myocardium over time in an experimental pig model. Emphasis was put on the dipyridamole effect when administered in the microdialysis probe inserted in ischemic myocardium. Not only adenosine but also taurine and pyruvate concentrations were significantly higher in the microdialysate during the periods of ischemia and extracorporeal circulation with cardioplegia. The enhanced efflux of taurine in ischemic myocardium induced by dipyridamole is a new finding. A mechanistic role of taurine in the prevention of Ca(2+) overload in ischemic myocytes is discussed. Also, taurine may have stimulatory effects on glycolysis in ischemic heart.


Asunto(s)
Isquemia Miocárdica/metabolismo , Nucleósidos/metabolismo , Taurina/metabolismo , Adenosina/metabolismo , Animales , Transporte Biológico/efectos de los fármacos , Dipiridamol/farmacología , Hipoxantina/metabolismo , Inosina/metabolismo , Lactatos/metabolismo , Microdiálisis , Ácido Pirúvico/metabolismo , Porcinos , Vasodilatadores/farmacología
16.
Scand J Clin Lab Invest ; 61(8): 651-62, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11768325

RESUMEN

The basic idea of retroperfusion of the coronary sinus (RCS) is to ameliorate detrimental consequences of myocardial ischaemia. Several experimental models of RCS have been introduced, most with an emphasis on functional myocardial status. Since only few studies have been devoted to energy metabolic considerations and none to continuous monitoring of energy-related metabolites of myocardium during RCS, we here present such a study using microdialysis. This study comprised the following components: Coronary occlusion and drainage on the beating heart with RCS-assist (60 min), hypothermic (30 degrees C) extracorporeal circulation (ECC) and cardioplegia (45 min), reperfusion and rewarming to 38 degrees C on ECC (30 min). The microdialysis analytical outcome mainly reflected anaerobic energy metabolism in potentially ischaemic myocardium. Additionally, a pronounced increase of microdialysate content of lactate, pyruvate and guanosine was observed in non-ischaemic myocardium especially during the reperfusion phase. The planimetric calculation revealed an infarct size reduction from 69% to 19% and was not correlated to clear-cut improvements of potentially ischaemic myocardial energy metabolism. We conclude that prolonged (60 min) anaerobic energy metabolism does not pose an immediate threat to cell viability but could even sustain myocyte survival.


Asunto(s)
Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Reperfusión Miocárdica/métodos , Miocardio/metabolismo , Miocardio/patología , Animales , Circulación Coronaria , Metabolismo Energético , Guanosina/metabolismo , Venas Yugulares , Ácido Láctico/metabolismo , Microdiálisis , Daño por Reperfusión Miocárdica/prevención & control , Ácido Pirúvico/metabolismo , Porcinos
17.
J Magn Reson Imaging ; 12(6): 866-72, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11105024

RESUMEN

The ultrasmall superparamagnetic iron oxide (USPIO) preparation NC100150 Injection (Clariscan; Nycomed Imaging, Oslo, Norway) was tested for its ability to delineate nonperfused myocardium under steady-state conditions. An experimental animal model of focal myocardial ischemia induced by ligation of the distal part of the left anterior descending artery was used. The contrast agent was administered in four doses: 0, 4, 8, and 12 mg Fe/kg body weight. Magnetic resonance examination ex vivo, including T1-, T2-, and T2*-weighted sequences, was performed. Nonperfused myocardium was determined by fluorescein. The best delineation of nonperfused myocardium was found with a T1-weighted inversion recovery/turbo spin-echo sequence and doses of 4 and 8 mg Fe/kg body weight, where 95% of the volume was discernible at the dose of 4 mg Fe/kg body weight. The results suggest that steady-state imaging by T1-weighted sequence with the use of NC100150 Injection to delineate nonperfused myocardium is feasible. J. Magn. Reson. Imaging 2000;12:866-872.


Asunto(s)
Medios de Contraste , Hierro , Imagen por Resonancia Magnética , Infarto del Miocardio/diagnóstico , Óxidos , Animales , Dextranos , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Óxido Ferrosoférrico , Nanopartículas de Magnetita , Masculino , Infarto del Miocardio/patología , Miocardio/patología , Sensibilidad y Especificidad , Porcinos
19.
Ann Neurol ; 46(5): 684-92, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10970245

RESUMEN

Twenty-one members of a Swedish family suffering from myopathy and cardiomyopathy underwent neurological and cardiological investigations. Medical charts of 2 affected deceased patients were reviewed. Twelve patients had myopathy. The distribution of weakness was axial in mildly affected, axial and predominantly distal in moderately affected, and generalized in severely affected patients. The electromyogram showed signs of myopathy in 10 patients. Muscle biopsy specimens showed myopathic changes, rimmed vacuoles, and accumulation of desmin, dystrophin, and other proteins. Electron microscopy revealed granulofilamentous changes and disorganization of myofibrils. Several patients had episodes of chest pain or palpitations. Three men had arrhythmogenic right ventribular cardiomyopathy. Nonsustained ventribular tachycardia, atrial flutter, and dilatation of the ventricles mainly affecting the right ventricle were documented. Two of them had a pacemaker implanted because of atrioventricular block and sick sinus syndrome. Inheritance is autosomal dominant with variable onset and severity of skeletal muscle and cardiac involvement. Linkage analysis of candidate chromosomal regions showed a maximum 2-point LOD score of 2.76 for marker locus D10S1752 on chromosome 10q. A multipoint peak LOD score of 3.06 between markers D10S605 and D10S215 suggests linkage to chromosome 10q22.3, and this region may harbor a genetic defect for myofibrillar myopathy with arrhythmogenic right ventricular cardiomyopahty.


Asunto(s)
Displasia Ventricular Derecha Arritmogénica/genética , Cromosomas Humanos Par 10 , Enfermedades Musculares/genética , Adulto , Displasia Ventricular Derecha Arritmogénica/patología , Displasia Ventricular Derecha Arritmogénica/fisiopatología , Biopsia , Desmina , Femenino , Ligamiento Genético , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Musculares/patología , Enfermedades Musculares/fisiopatología , Examen Neurológico , Linaje , Síndrome
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA