RESUMO
AIM: To investigate the frequency of sonographic findings that required neurosurgical consultation for all referred outpatients suspected to have benign macrocrania (BMC). MATERIALS AND METHODS: A retrospective review was performed from September 2011 until June 2015 for all outpatients referred to the ultrasound (US) department for BMC. Electronic medical records, US images, and reports were reviewed in conjunction with follow-up imaging. Each review consisted of gender, specialty of referring physician, first head circumference, head circumference at or closest to the time of the head US, the last head circumference, and any neurological issue prior to the US, at the time of US, or following the US, and clinical outcomes. Statistical analysis employed the Kruskal-Wallis rank sum test and Fischer's exact test (chi square test of independence) that compared normal/BMC patients from the patients requiring a neurosurgical consultation. RESULTS: One hundred and thirty (40.9%) had a normal head US, 181 patients (56.9%) had sonographic findings of BMC, and seven (2.2%) patients had an abnormal head US that required a neurosurgical consultation. Of the 181 patients with BMC, 23 underwent follow-up imaging with 22 patients having unchanged BMC or a normal head US and one patient developing mild ventriculomegaly that was stable on follow-up imaging. Three of the seven patients (1%) aged 1.8, 2.3, and 13.1 months with abnormal head US requiring neurosurgical consultation, had mild ventriculomegaly that was stable on follow-up imaging. Four of the seven patients (1.2%) that required neurosurgical consultation needed a neurosurgical procedure. Between the two US subgroups (normal and BMC), no statistical significance was noted regarding age of patient at US, head circumference at clinical and radiological presentation (p>0.05) except for the first head circumference clinically documented which demonstrated statistical significance (p<0.03). CONCLUSION: Short interval surveillance including head circumference and assessment for the development of bulging anterior fontanelle and neurological abnormalities may be more cost effective than US in the initial evaluation of patients clinically suspected to have BMC.
Assuntos
Cabeça/anormalidades , Cabeça/diagnóstico por imagem , Megalencefalia/diagnóstico por imagem , Ultrassonografia/métodos , Feminino , Humanos , Lactente , Masculino , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Postoperative mortality after coronary artery bypass grafting (CABG) surgery is traditionally considered to be influenced by gender. However, the data are conflicting and it is not clear whether gender is a true independent risk factor for death in this setting. We analyzed our database to determine whether gender is an independent risk factor for death after CABG. PATIENTS AND DESIGN: A retrospective analysis of 1 758 isolated first-time coronary artery bypass graft patients treated between 2003 and 2005 was conducted in the Department of Cardiothoracic Surgery of Rabin Medical Center, a major tertiary facility in Israel. RESULTS: The female patients had a distinctly different pre- and intraoperative profile compared with the male patients, and significantly higher postoperative mortality (p < 0.05). On a propensity scoring of 359 matched pairs, the risk factors for death were found to be severe left ventricular dysfunction, chronic obstructive pulmonary disease, and use of an intra-aortic balloon pump (p < 0.05). The addition of intraoperative data to the model yielded only cardiopulmonary bypass time and use of an intra-aortic balloon pump as risk factors for death (p < 0.05). Validation with the bootstrap technique revealed that strong predictors of death (> 50 % of the sample) were cardiopulmonary bypass time, use of an intra-aortic balloon pump, and, to a lesser extent, chronic obstructive pulmonary disease. Female gender was not found to be an independent risk factor for death after coronary artery bypass graft. CONCLUSIONS: Female gender is apparently not an independent risk factor for coronary artery bypass graft mortality in this patient group.
Assuntos
Ponte de Artéria Coronária/mortalidade , Doença da Artéria Coronariana/cirurgia , Fatores Sexuais , Fatores Etários , Idoso , Ponte Cardiopulmonar , Doença da Artéria Coronariana/complicações , Feminino , Humanos , Balão Intra-Aórtico/efeitos adversos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/complicações , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
Intravenous leiomyomatosis is a rare, benign neoplasm of the uterine, affecting adult women. We report two cases in whom intravenous leiomyomatosis extended through the inferior vena cava into the right heart chambers and the pulmonary artery. Both patients underwent staged operation with excision of the cardiac and primary tumour. The differential diagnosis of a right atrial mass in middle-aged women should include intravenous leiomyomatosis.
Assuntos
Átrios do Coração , Neoplasias Cardíacas/diagnóstico por imagem , Neoplasias Cardíacas/secundário , Leiomiomatose/diagnóstico por imagem , Leiomiomatose/patologia , Neoplasias Uterinas/diagnóstico por imagem , Neoplasias Uterinas/patologia , Diagnóstico Diferencial , Feminino , Neoplasias Cardíacas/cirurgia , Humanos , Leiomiomatose/cirurgia , Pessoa de Meia-Idade , Resultado do Tratamento , Ultrassonografia , Neoplasias Uterinas/cirurgia , Veia Cava InferiorRESUMO
OBJECTIVE: Open-heart surgery carries a high risk for hemodialysis patients. This study focuses on the short and long-term outcomes of hemodialysis patients undergoing heart surgery. DESIGN: The study was carried out as a retrospective analysis in the Department of Cardiothoracic Surgery in a large university-affiliated hospital. PATIENTS: 115 hemodialysis patients underwent cardiac surgery in our department between 1 July 1996 and 31 July 2006. 67.5 % (77 patients) underwent isolated coronary artery bypass grafting (CABG), 13.2 % (15 patients) underwent isolated aortic valve replacement (AVR) and 20.2 % (23 patients) underwent mitral valve surgery or combined valve and coronary artery bypass grafting or multiple valve surgery. METHODS: The relationship between several variables (age, sex, hypertension, diabetes, and previous myocardial infarction, type of disease, preoperative ejection fraction, and congestive heart failure) and operative (30 days) mortality and late survival was analyzed. RESULTS: The overall 30-day mortality was 18.3 % (21 patients). It was 13 % (10/77 patients) for the isolated CABG group and 13.3 % (2/15) for the isolated AVR group. Patients undergoing combined valve and coronary surgery or multiple valve surgery had a higher perioperative mortality of 39.1 % (9/23) compared to the isolated CABG and isolated AVR patients. Perioperative death was also higher in patients with moderate and severe LV dysfunction, and in patients with diabetes. The duration of dialysis periods was not related to perioperative death. Mean follow-up was 26.4 +/- 29.7 months (0.1 to 104 months). Actuarial survival at 1 year and 5 years was 76 % and 55 % for isolated CABG, 59 % and 21 % for isolated AVR, and 44 % and 33 % for all other cases, respectively (log rank P = 0.001). CONCLUSION: Patients on dialysis have a high risk of perioperative mortality and poor long-term survival rates. Mortality is higher and survival is worse after combined CABG and valve-related procedures or multiple valve surgery than after isolated CABG and AVR.
Assuntos
Procedimentos Cirúrgicos Cardíacos/mortalidade , Doenças Cardiovasculares/cirurgia , Falência Renal Crônica/terapia , Diálise Renal/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/mortalidade , Feminino , Seguimentos , Humanos , Israel/epidemiologia , Falência Renal Crônica/complicações , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida/tendências , Fatores de TempoAssuntos
Transplante de Coração/fisiologia , Hipertensão Pulmonar/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Adulto , Ecocardiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Fatores de TempoAssuntos
Colesterol/sangue , Transplante de Coração/imunologia , Hiperlipidemias/epidemiologia , Terapia de Imunossupressão/métodos , Corticosteroides/uso terapêutico , Ciclosporina/uso terapêutico , Seguimentos , Humanos , Hidroximetilglutaril-CoA Redutases/uso terapêutico , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Tacrolimo/uso terapêutico , Fatores de TempoRESUMO
BACKGROUND AND AIM OF THE STUDY: In order to provide valved xenografts with reduced immunity, yet durability comparable with that of homografts, a method for endothelial cell removal was developed. METHODS: Adult porcine valved pulmonary conduits were isolated, washed and incubated in trypsin-EDTA solution. The endothelial cells were flushed free with a stream of culture medium, and the xenografts cryopreserved. Grafts were thawed after three months, and evaluated structurally. RESULTS: Macroscopic inspection of the grafts revealed no cracks or other morphological damage. Light microscopy revealed mildly edematous changes, and the elastic layers appeared to be preserved. Incubation with trypsin-EDTA solution consistently removed the entire endothelial layer, without obvious damage to the underlying tissues. CONCLUSION: With care and appropriate timing, the xenograft endothelium can be selectively removed, leaving the underlying tissue intact. This process may allow further structural manipulations to improve the durability of these grafts.
Assuntos
Bioprótese , Próteses Valvulares Cardíacas , Transplante Heterólogo/imunologia , Animais , Criopreservação , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Humanos , Tolerância Imunológica/imunologia , Técnicas Imunoenzimáticas , Desenho de Prótese , SuínosAssuntos
Ciclosporina/efeitos adversos , Transplante de Coração/imunologia , Imunossupressores/uso terapêutico , Ácido Úrico/sangue , Adulto , Azatioprina/uso terapêutico , Ciclosporina/sangue , Quimioterapia Combinada , Transplante de Coração/mortalidade , Transplante de Coração/fisiologia , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/sangue , Prednisona/uso terapêutico , Taxa de SobrevidaRESUMO
BACKGROUND: Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital malformation that presents a diagnostic challenge to the pediatrician and pediatric cardiologist. Although surgical repair is always indicated, the optimal technique has yet to be determined. OBJECTIVES: To review our experience with the diagnosis of children with ALCAPA and to assess short to midterm surgical results. METHODS: Between 1992 and 1998, 13 infants and children (2 months to 15 years) were treated for ALCAPA at our medical center. Eight were diagnosed during the first year of life; all were symptomatic and had severe dysfunction of the left ventricle. The five patients diagnosed at an older age had normal myocardial function. Diagnosis was established by echocardiography alone in seven patients; six required catheterization (one infant and all older patients). Surgery was performed in 12 patients to establish dual coronary artery system: 7 underwent the Takeuchi procedure and 5 had re-implantation of the anomalous left coronary artery. RESULTS: One infant died shortly after diagnosis before surgical repair was attempted, and one died postoperatively. Four patients required additional surgery: three for late complications of the Takeuchi procedure and one valve replacement for mitral insufficiency. Recent evaluation revealed good global left ventricle function in all patients except for one, who is still within the recovery phase and shows gradual improvement. However, most patients who presented with severe myocardial dysfunction upon diagnosis still display abnormal features such as echo-dense papillary muscles or evidence of small akinetic segments. In this group, early repair was associated with faster myocardial recovery. CONCLUSIONS: The diagnosis of ALCAPA remains a clinical challenge to the pediatrician and cardiologist. Diagnosis can be established echocardiographically, and early diagnosis and treatment may lead to faster myocardial recovery. The preferred surgical method appears to be re-implantation of the ALCA. The chance for good recovery of global ventricular function is high even in the sickest patients, nonetheless abnormal myocardial features can be identified even years after surgery.
Assuntos
Anomalias dos Vasos Coronários/diagnóstico , Anomalias dos Vasos Coronários/cirurgia , Adolescente , Cateterismo Cardíaco , Procedimentos Cirúrgicos Cardíacos/métodos , Criança , Pré-Escolar , Anomalias dos Vasos Coronários/complicações , Anomalias dos Vasos Coronários/mortalidade , Ecocardiografia Doppler em Cores , Seguimentos , Humanos , Lactente , Israel/epidemiologia , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/cirurgia , Taxa de Sobrevida , Resultado do TratamentoRESUMO
OBJECTIVE: The internal thoracic artery has become the conduit of choice for coronary artery bypass grafting. To avoid spasm of the artery, and increases in its diameter and flow, various vasodilators have been used either intraluminally or by topical application by different surgeons. In order to define the best vasodilating agent for preparation of the internal thoracic artery, a randomized double-blind placebo-controlled clinical study was performed in a group of patients submitted for elective coronary artery bypass grafting. METHODS AND RESULTS: Eighty (80) consecutive patients submitted for elective first time coronary artery bypass grafting were randomly subdivided into five treatment groups. Free flow of the left internal thoracic artery was measured using an electromagnetic flow meter. The first measurement was performed shortly after the internal thoracic artery was dissected from the chest wall and the second just prior to performing distal anastomosis to the left anterior descending coronary artery. During the time interval between the two measurements the internal thoracic artery was immersed in a special applicator tube containing 20 ml solution of one of the following drugs: papaverin 2 mg/ml, nitroglycerin 1 mg/ml, verapamil 0.5 mg/ml, nitroprusside 0.5 mg/ml, normal saline 0.9%. RESULTS: No statistically significant differences were found between the groups in respect to age, body surface area, bypass time, cross clamping time, and time interval between the two flow measurements. Mean arterial pressure at the time of the first and second internal thoracic artery flow measurements did not show statistically significant differences either within or between the groups. In all five groups, the free flow of the internal thoracic artery increased significantly with time. However, no statistically significant differences were shown between the five groups with respect to second flow (P = 0.2). CONCLUSIONS: Within the limits of our study design, we suggest that preparation of the LITA by topical vasodilator drugs using a special applicator tube does not result in a significantly superior free flow than placebo.
Assuntos
Ponte de Artéria Coronária/métodos , Artéria Torácica Interna/efeitos dos fármacos , Vasodilatadores/administração & dosagem , Idoso , Anastomose Cirúrgica/métodos , Doença das Coronárias/cirurgia , Método Duplo-Cego , Feminino , Seguimentos , Hemodinâmica/fisiologia , Humanos , Masculino , Artéria Torácica Interna/transplante , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Probabilidade , Valores de Referência , Doenças Vasculares/prevenção & controle , Grau de Desobstrução VascularRESUMO
OBJECTIVE: The lung injury regularly associated with cardiopulmonary bypass (CPB) may be linked to gut mucosal dysfunction occurring as the result of mucosal ischemia associated with nonpulsatile CPB. To examine this possibility we postulated that the weak-beta 2 agonist dopexamine would improve gut mucosal blood flow, thereby decreasing gut and lung dysfunction seen after CPB in sheep. METHODS: Anesthetized sheep had 2 h of hypothermic (24 degrees C), nonpulsatile CPB, and 60 min of cold, blood cardioplegic arrest. After warming they were separated from CPB for 2 h of reperfusion. Before and during CPB, dopexamine at 2 micrograms/kg/min (n = 7) or saline (n = 7) were infused in a blinded fashion. Hemodynamic parameters were measured. Biatrial thromboxane B2 levels were obtained. Mesenteric arterial flow (QSMA), mucosal flow (Qmuc), FD-4 clearance (ClFD-4), and tonometric pHi were measured at baseline and 30-min intervals on, and after, CPB. RESULTS: After CPB, similar reductions in MAP were seen (P < 0.05 vs. baseline), but heart rate and the mean pulmonary vascular resistance were significantly increased in the dopexamine animals (P < 0.05 vs. placebo). Plasma thromboxane was similarly increased in both groups after CPB (P < 0.05 vs. baseline), returning to baseline 1 h after CPB. The Qsma was not altered, but a statistically significant decrease in Qmuc and pHi occurred in both groups (P < 0.05 vs. baseline). In both groups FD-4 clearance reached a peak 30 min after CPB (P < 0.05; dopexamine vs. baseline). After 2 h neither of these changes returned to control levels. CONCLUSIONS: In this ovine model, gut mucosal ischemia and increased permeability occur with hypothermic CPB, but dopexamine administration during CPB, compared to placebo, neither ameliorates these intestinal derangements nor reduces post-CPB lung pathophysiology.
Assuntos
Agonistas Adrenérgicos beta/farmacologia , Ponte Cardiopulmonar , Dopamina/análogos & derivados , Mucosa Intestinal/irrigação sanguínea , Pulmão/irrigação sanguínea , Traumatismo por Reperfusão/fisiopatologia , Animais , Permeabilidade Capilar , Ponte Cardiopulmonar/efeitos adversos , Dopamina/farmacologia , Hemodinâmica/fisiologia , Concentração de Íons de Hidrogênio , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiologia , Oxigênio/metabolismo , Circulação Pulmonar/efeitos dos fármacos , Circulação Pulmonar/fisiologia , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/etiologia , Ovinos , Tromboxano B2/sangueRESUMO
A number of heparin-binding growth factors, including basic (bFGF) and acidic (aFGF) fibroblast growth factors have been shown to promote angiogenesis in vivo. In this study, we employed a sustained-release polymer extravascular delivery system to evaluate the angiogenic efficacy of a novel form of genetically modified aFGF in the setting of chronic myocardial ischemia. Fifteen Yorkshire pigs subjected to Ameroid occluder placement on the left circumflex (LCX) artery were treated with perivascularly administered aFGF in ethylene vinyl acetate (EVAc) polymer (10 micrograms, n = 7) or EVAc alone (controls, n = 8). Seven to nine weeks later, after coronary angiography to document Ameroid-induced coronary occlusion, all animals underwent studies of coronary flow and global and regional left ventricular function. Microsphere-determined coronary flow in the Ameroid-compromised territory was significantly increased in aFGF-treated compared with control animals, and this improvement in perfusion was maintained during ventricular pacing. Left ventricular function studies demonstrated improved global and regional function in aFGF-treated animals. We conclude that local perivascular delivery of genetically modified aFGF results in significant improvement in myocardial flow and regional and global left ventricular function.
Assuntos
Fator 1 de Crescimento de Fibroblastos/administração & dosagem , Isquemia Miocárdica/fisiopatologia , Neovascularização Fisiológica/efeitos dos fármacos , Animais , Circulação Coronária , Modelos Animais de Doenças , Fatores de Crescimento Endotelial/farmacologia , Ventrículos do Coração/patologia , Linfocinas/farmacologia , Contração Miocárdica , Proteínas Recombinantes , Suínos , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
OBJECTIVE: Previous investigations have shown the effectiveness of sustained intra- or extravascular administration of vascular endothelial growth factor (VEGF) in chronic myocardial ischemia in improvement of left ventricular function. The present investigations were undertaken in order to evaluate efficacy of a single bolus or local intracoronary delivery. METHODS: Yorkshire pigs underwent placement of a left circumflex artery ameroid occluder. Three weeks later the animals were randomized to treatment with VEGF (20 micrograms) accomplished by local intracoronary delivery system (InfusaSleeve, n = 10), intracoronary bolus infusion (n = 7) or by epicardial implantation of an osmotic delivery system (n = 7). An additional group of animals received intracoronary administration of saline and served as a control (n = 9). Three weeks after initiation of therapy, the animals were evaluated with regard to myocardial perfusion and global as well as regional ventricular function. RESULTS: All three VEGF treatment groups but not the control animals demonstrated a significant increase in the left-to-left (but not right-to-left) collateral index, myocardial blood flow (pre-therapy LCX vs. LAD (average of all groups): 0.76 +/- 0.35 vs. 0.96 +/- 0.38 ml*min-1*g-1, p = 0.03; post-therapy: LCX vs. LAD: 1.16 +/- 0.39 vs. 1.15 +/- 0.28 ml*min-1*g-1, p = NS) and coronary vasodilatory reserve 3 weeks after growth factor administration. The observed increase in VEGF-induced perfusion correlated with improvement in regional ventricular function in all VEGF-treated groups (pre-therapy vs. post-therapy: i.c. VEGF 20 +/- 5.1 vs. 33 +/- 4.8; local VEGF 16 +/- 2.8 vs. 33.6; pump VEGF 17 +/- 3.8 vs. 34 +/- 4.9 p < 0.05 for all) but not control animals (21 +/- 3.3 vs. 27 +/- 5.8, p = NS). CONCLUSION: Single intracoronary delivery (intravascular bolus or local delivery) of VEGF is effective in stimulating physiologically significant angiogenesis in porcine model of chronic myocardial ischemia.
Assuntos
Fatores de Crescimento Endotelial/administração & dosagem , Linfocinas/administração & dosagem , Isquemia Miocárdica/tratamento farmacológico , Função Ventricular Esquerda/efeitos dos fármacos , Animais , Doença Crônica , Angiografia Coronária , Circulação Coronária/efeitos dos fármacos , Fatores de Crescimento Endotelial/uso terapêutico , Bombas de Infusão Implantáveis , Infusões Intra-Arteriais , Injeções Intra-Arteriais , Linfocinas/uso terapêutico , Imageamento por Ressonância Magnética , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Distribuição Aleatória , Estatísticas não Paramétricas , Suínos , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
BACKGROUND: The beta-adrenergic-cAMP pathway importantly regulates cerebral blood flow. Previous studies have found that normothermic cardiopulmonary bypass (CPB) is associated with reduced cerebral beta-adrenoceptor-mediated relaxation. METHODS AND RESULTS: In order to examine the effects of hypothermic CPB on regulation of perfusion by the beta-adrenergic-cAMP pathway, pigs were placed on moderately (25 degrees C) or profoundly hypothermic (16 degrees C with 1 hour of circulatory arrest) or normothermic (37 degrees C) CPB for 2 hours. After normothermic perfusion for 15 minutes and separation from CPB, cerebral microvascular responses to the beta-adrenoceptor agonist isoproterenol (ISO), the adenylate cyclase activator forskolin, and the stable cAMP analogue 8-bromo-cAMP were examined in vitro in a pressurized, no-flow state. Baseline internal carotid artery blood flow was similar and unchanged after rewarming in the three experimental groups. However, ISO (100 micromol/L) elicited less relaxation after moderately hypothermic CPB (75+/-6%, P<.05 versus control, percent of U46619 induced precontraction) and profoundly hypothermic circulatory arrest (42+/-5%, P<.05) than in vessels from uninstrumented controls (91+/-2%) or after normothermic CPB (84+/-4%). The relaxation to forskolin was reduced after profoundly hypothermic circulatory arrest (83+/-3%, P<.05), but was similar in the other groups (92+/-2% control). Surprisingly, relaxation induced by 8-bromo-cAMP was markedly reduced after normothermic CPB, and this change was directly related to temperature during CPB. The intraluminal exposure of vessels to zymosan-induced complement activated serum had no effect on relaxation to ISO, while 2 hours of exposure of vessels to ISO caused a dose-dependent reduction in subsequent relaxation to ISO, but not to forskolin. CONCLUSIONS: Moderately hypothermic CPB or PHCA desensitizes alpha-adrenoceptors more than normothermic CPB. This is likely due in part to the exposure of vessels to endogenous catecholamines during CPB. Thus, whereas baseline cerebral blood flow is similar after normothermic and hypothermic CPB, beta-adrenergic responses are markedly abnormal.
Assuntos
Ponte Cardiopulmonar , Circulação Cerebrovascular , Receptores Adrenérgicos beta/fisiologia , Adenilil Ciclases/metabolismo , Animais , Pressão Sanguínea , AMP Cíclico/fisiologia , Feminino , Hipotermia Induzida , Isoproterenol/farmacologia , Masculino , Microcirculação , SuínosRESUMO
BACKGROUND: Cardioplegia is known to affect coronary vascular reactivity. We examined the effects of intermittent cold and continuous warm blood cardioplegia on beta-adrenoceptor-mediated, adenosine triphosphate-sensitive K+ (K+ATP)-channel-mediated, and endothelium-dependent relaxation and on the myogenic tone of coronary arterioles. METHODS: Pigs were placed on cardiopulmonary bypass. Hearts were arrested for 1 hour with a cold blood cardioplegic solution administered intermittently (n = 12; iCB-CP) or with a warm blood cardioplegic solution delivered continuously (n = 12; cWB-CP). Selected hearts (n = 6 in each group) were then reperfused for 1 hour. In vitro relaxation responses of precontracted microvessels (50 to 160 microns) were studied in a pressurized no-flow state. RESULTS: Relaxation in response to isoproterenol (beta-adrenergic agonist) was similar after iCB-CP and cWB-CP, whereas forskolin (adenylate cyclase activator)-induced relaxation was impaired more after iCB-CP than after cWB-CP. After reperfusion the respective responses were similar. Both iCB-CP and cWB-CP preserved receptor-mediated, endothelium-dependent relaxation in response to adenosine, 5'-diphosphate; non-receptor-mediated endothelium-dependent relaxation in response to A23187; endothelium-independent cyclic guanosine monophosphate-mediated relaxation in response to sodium nitroprusside, and K+ATP-channel-mediated relaxation. Relaxations in response to 8-bromo-cyclic guanosine monophosphate (a cyclic guanosine monophosphate-dependent protein kinase activator) and to 8-bromo-cyclic adenosine monophosphate (a cyclic adenosine monophosphate-dependent protein kinase activator) were impaired after iCB-CP alone and after reperfusion, whereas the respective responses were not affected after cWB-CP. Myogenic tone was decreased similarly after iCB-CP and cWB-CP but was not further altered after reperfusion. Cardiac function was similar after iCB-CP and cWB-CP. CONCLUSIONS: These results suggest that cWB-CP is similar to iCB-CP in its ability to preserve endothelium-dependent relaxation and K+ATP-channel function. The superior preservation of beta-adrenergic-cyclic adenosine monophosphate-mediated coronary responses after cWB-CP is brief and associated with minimal improvement of myocardial function and myogenic tone.
Assuntos
Sangue , Vasos Coronários/fisiologia , Parada Cardíaca Induzida/métodos , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Difosfato de Adenosina/farmacologia , Adenilil Ciclases/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , Calcimicina/farmacologia , Colforsina/farmacologia , Vasos Coronários/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , GMP Cíclico/farmacologia , Endotélio Vascular/fisiologia , Ativação Enzimática , Guanidinas/farmacologia , Técnicas In Vitro , Isoproterenol/farmacologia , Microcirculação/efeitos dos fármacos , Microcirculação/fisiologia , Pinacidil , Canais de Potássio/metabolismo , Suínos , Temperatura , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Vasodilatadores/farmacologiaRESUMO
BACKGROUND: Cardiopulmonary bypass (CPB) is associated with alterations in the regulation of organ perfusion and vascular permeability. The purpose of this study was to examine the effects of hypothermic CPB on the regulation of the skeletal muscle microcirculation and the modulating influence of the priming solution. METHODS: Sheep were placed on hypothermic CPB with a prime of either Pentastarch hydroxylethyl starch (HS) solution (n = 7), a solution in which HS is conjugated with deferoxamine (n = 7), or Ringer's lactate solution (n = 7). Sheep were placed on hypothermic CPB (27 degrees C) for 90 minutes while the heart was protected with cold blood cardioplegia. Sheep were then separated from CPB and perfused for an additional 3 hours off CPB. Hemodynamics and total water content were measured. RESULTS: In vitro relaxation responses of gracilis muscle arterioles (70 to 180 microns) to the endothelium-dependent agent acetylcholine, the endothelium-independent cyclic GMP-mediated vasodilator sodium nitroprusside, the beta-adrenergic agonist isoproterenol, and the adenylate cyclase activator forskolin were studied. No statistically significant hemodynamic differences were observed between groups. However, weight gain was significantly less when the priming solution was HS or HS-deferoxamine compared to when Ringer's lactate was used. Skeletal muscle arteriolar relaxations to the endothelium-dependent vasodilator acetylcholine and the beta-adrenergic agonist isoproterenol were impaired after CPB in the HS and Ringer's lactate groups. Acetylcholine response was preserved in the HS-deferoxamine group, whereas the response to isoproterenol remained impaired. The responses to sodium nitroprusside and forskolin were similar in all groups. CONCLUSIONS: Skeletal muscle microvascular endothelium-dependent relaxation and beta-adrenergic relaxation are reduced after CPB using either a crystalloid or HS prime. Skeletal muscle microvascular endothelial dysfunction may be attributable to oxygen-derived free radical-mediated injury, whereas altered beta-adrenergic regulation is attributable to mechanisms other than the generation of oxygen-derived free radicals during CPB.
Assuntos
Ponte Cardiopulmonar , Músculo Esquelético/irrigação sanguínea , Sistema Vasomotor/fisiologia , Acetilcolina/farmacologia , Adenilil Ciclases/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , Colforsina/farmacologia , Desferroxamina/farmacologia , Guanilato Ciclase/metabolismo , Derivados de Hidroxietil Amido/farmacologia , Técnicas In Vitro , Isoproterenol/farmacologia , Soluções Isotônicas/farmacologia , Microcirculação , Nitroprussiato/farmacologia , Lactato de Ringer , Ovinos , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacosRESUMO
Recently, a number of growth factors including basic fibroblast growth factor (bFGF) have been shown to promote angiogenesis in vivo. In this study, we evaluated dose-dependent effect of bFGF administration in the setting of chronic myocardial ischemia. A total of 18 Yorkshire pigs subjected to ameroid occluder placement on the left circumflex artery were randomized to treatment with 10 (n = 6) or 100 microg (n = 5) of bFGF incorporated into heparin-alginate microspheres or inactive control pellets (n = 7). Eight weeks later, all animals underwent angiographic evaluation of collateral development as well as studies of coronary flow and global and regional left ventricular function. Both bFGF groups had significantly higher angiographic collateral index, TIMI flow scores and coronary flow in the ameroid-compromised territory compared with controls. Left ventricular function studies demonstrated improved global and regional function in both fibroblast growth factor groups with significantly better preservation of regional wall motion in high dose (100 microg) bFGF animals. We conclude that local perivascular delivery of bFGF results in significant improvement in myocardial function in the setting of chronic myocardial ischemia.