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1.
Int J STD AIDS ; 23(9): 679-80, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23033527

RESUMO

Primary cutaneous aspergillosis is rare but has been described in immunosuppressed individuals. Cutaneous aspergillosis associated with HIV infection, to date, has primarily been described in hospitalized individuals with advanced HIV following skin trauma. We describe a case of primary cutaneous aspergillosis in a HIV-infected, antiretroviral therapy naïve patient with moderate immunosuppression.


Assuntos
Aspergilose/virologia , Dermatomicoses/virologia , Infecções por HIV/microbiologia , Adulto , Aspergilose/patologia , Dermatomicoses/patologia , Feminino , Infecções por HIV/patologia , Histocitoquímica , Humanos , Pele/microbiologia , Pele/patologia
3.
Ann N Y Acad Sci ; 874: 306-19, 1999 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-10415542

RESUMO

We developed a model of ischemia and reperfusion (I and R) in human ventricular myocytes (CM). CM injury and metabolics were studied after various interventions: endogenous preconditioning (PC) with anoxia, hypoxia, and anoxic or hypoxic supernatants; endogenous PC with or without SPT or adenosine deaminase; and exogenous adenosine PC before, during, or after I or continuously, with or without SPT. To assess the clinical implications of PC and the possible mediating effects of adenosine, patients undergoing elective coronary bypass surgery (CABG) received either a high or low dose of adenosine. Patients not receiving adenosine served as controls. Adenosine levels, high-energy phosphate levels, the metabolic parameters were evaluated from blood samples and left ventricular biopsy samples. Our cellular model studies indicated that preconditioning conferred protection to human CM via an adenosine-mediated pathway. Adenosine simulated PC without a fall in ATP. Adenosine administered to patients during CABG stimulated myocardial metabolism while preventing the degradation of high energy phosphates. A prospective randomized trial of adenosine administered to high-risk patients for myocardial protection is required.


Assuntos
Precondicionamento Isquêmico Miocárdico , Adenosina/sangue , Adenosina/metabolismo , Adenosina/farmacologia , Trifosfato de Adenosina/sangue , Trifosfato de Adenosina/metabolismo , Células Cultivadas , Ponte de Artéria Coronária , Metabolismo Energético/fisiologia , Ventrículos do Coração , Humanos , Precondicionamento Isquêmico Miocárdico/métodos , Ácido Láctico/biossíntese , Miocárdio/citologia , Miocárdio/metabolismo , Antagonistas de Receptores Purinérgicos P1 , Teofilina/análogos & derivados , Teofilina/farmacologia
4.
Circulation ; 98(19 Suppl): II184-94; discussion II194-6, 1998 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-9852902

RESUMO

BACKGROUND: Adenosine (ADE) may mediate the protective effects of preconditioning (PC). However, human data are lacking, and the optimal method of ADE administration and the mechanism of protection remain unresolved. METHODS AND RESULTS: We have developed a model of simulated "ischemia" (I) and "reperfusion" (R) in quiescent human ventricular cardiomyocytes. Cellular injury and metabolic parameters were assessed after various interventions: Cells were preconditioned with anoxia (PC0), hypoxia (PC16), anoxic supernatant (SUP0), or hypoxic supernatant (SUP16) with or without the ADE receptor antagonist (SPT) or ADE deaminase (ADA). ADE was applied before, during, or after I or continuously with and without SPT. Cells were treated with the PKC agonist PMA. PC cells were incubated with the protein kinase-C (PKC) antagonist Calphostin-C (Cal-C). PKC translocation and PKC activity were assessed. PC0 was most protective. Protection was transferable via SUP0, which produced the highest concentrations of ADE. Protection was lost with SPT or ADA. Intracellular ATP fell after PC and prolonged I and R. Exogenous ADE was most protective when administered before I at 50 mumol. ADE during I was partially protective. No additional protection was provided with continuous ADE treatment. ADE prevented ATP degradation but increased lactate immediately after its administration. SPT abolished the protective effects of ADE. PMA conferred protection, which was abolished with Cal-C. ADE stimulated PKC translocation and PKC activity in the absence of SPT. CONCLUSIONS: Maximal I confers maximal PC. The degree of I is reflected in supernatant ADE concentrations. The initial ATP fall with PC may account for a lack of ATP preservation after I and R. ADE reproduces the protective effects of PC, preserves ATP, and increases lactate production, perhaps by stimulating glycolysis. Clinical trials of ADE administered during cardiac surgery are necessary to further define its beneficial effects in humans.


Assuntos
Precondicionamento Isquêmico Miocárdico , Isquemia Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Adenosina/metabolismo , Adenosina/farmacologia , Relação Dose-Resposta a Droga , Humanos , Miocárdio/citologia , Miocárdio/metabolismo , Proteína Quinase C/metabolismo , Antagonistas de Receptores Purinérgicos P1 , Teofilina/análogos & derivados , Teofilina/farmacologia
5.
Ann Thorac Surg ; 65(3): 674-83, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9527194

RESUMO

BACKGROUND: Aprotinin (APR) reduces postoperative blood loss but may induce thrombosis. Dipyridamole (DIP) limits platelet aggregation and may reduce the thrombotic complications associated with APR. METHODS: To evaluate the safety and effectiveness of combined APR and DIP, we undertook a prospective randomized trial in patients undergoing cardiac operations. Patients were stratified according to risk for bleeding (low or high), and received either DIP with placebo (DIP group; n = 59) or DIP with APR (DIP + APR group; n = 56). Blood samples were obtained for the measurement of hematologic and biochemical parameters. Blood loss and transfusion requirements were documented postoperatively. RESULTS: Postoperative blood loss and transfusion requirements were significantly lower in the DIP + APR group at 6, 12, and 24 hours after bypass (p < 0.01). No significant differences were found between groups in the incidence of perioperative mortality (DIP, 0%; DIP + APR, 3%), myocardial infarction (DIP, 0%; DIP + APR, 3%), stroke (DIP, 1%; DIP + APR, 1%), or potential thrombotic events (death, myocardial infarction, and stroke: DIP, 2%; DIP + APR, 5%). In addition, these rates did not differ from those of nonparticipating matched control patients. CONCLUSIONS: Administration of both drugs simultaneously was more effective than DIP alone in reducing postoperative blood loss. A platelet inhibitor may be required to reduce the thrombotic complications associated with APR. Further studies evaluating graft patency and perioperative ischemia are necessary to confirm the potential benefits of the combination of a platelet inhibitor and APR.


Assuntos
Aprotinina/administração & dosagem , Dipiridamol/administração & dosagem , Hemostáticos/administração & dosagem , Inibidores da Agregação Plaquetária/administração & dosagem , Hemorragia Pós-Operatória/prevenção & controle , Coagulação Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Revascularização Miocárdica , Estudos Prospectivos , Resultado do Tratamento
6.
Circulation ; 96(9 Suppl): II-179-86; discussion 186-7, 1997 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-9386095

RESUMO

BACKGROUND: Fetal rat cardiomyocytes transplanted into left ventricular scar tissue of the adult rat heart limit scar expansion and improve heart function. This study determined morphologic changes of transplanted fetal rat cardiomyocytes in myocardial scar tissue. METHODS AND RESULTS: The left ventricles of 500-g Sprague-Dawley rats were cryodamaged. At 4 weeks after myocardial injury, a transmural scar (54+/-11 mm2) (mean+/-1 SDak) formed at the apex (n=6). Cardiomyocytes freshly isolated from 18-day-gestation Sprague-Dawley rat hearts were transfected with plasmid containing the beta-galactosidase and then injected into the 4-week-old scar tissue. Cell culture medium was injected into the scar tissue of control animals. At 4 weeks posttransplantation, the cardiomyocytes had formed cardiac tissue (20.7+/-6.9 mm2, n=14), which stained positively for beta-galactosidase activity in the scar (90.4+/-25 mm2, n=14). The transplanted cardiomyocytes formed sarcomeres and were linked by junctions composed of desmosomes and fascia adherens. Lymphocyte infiltration occurred despite use of cyclosporin A. No myocardial tissue was found in the scar tissue of the control animals (n=14). More arterioles and venules were found (P<.01) in the cardiomyocyte grafts (1.2+/-0.6 vessel/0.8 mm2; n=14) than in the control scar tissue (0.1+/-0.1 vessels/0.8 mm2; n=14). At 20 weeks post-transplantation, the transplant tissue size (6+/-6 mm2; n=7) was smaller (P=.007) than 4-week old transplant, and the scar (162+/-46 mm2; n=7) was larger (P=.005) than 4-week-old scar. Lymphocyte infiltration was still present among the remaining transplanted cells. CONCLUSIONS: This study demonstrated that cardiac tissue formed by transplanted fetal cardiomyocytes in the myocardial scar tissue decreased in size with time probably secondary to rejection.


Assuntos
Transplante de Células , Coração Fetal/citologia , Transplante de Tecido Fetal , Animais , Cicatriz , Feminino , Gravidez , Ratos , Ratos Sprague-Dawley
8.
J Thorac Cardiovasc Surg ; 112(3): 787-96, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8800169

RESUMO

UNLABELLED: Neither antegrade nor retrograde cardioplegic protection provides homogeneous distribution, and a combination may be required to avoid anaerobic metabolism and depressed postoperative ventricular function. Tepid cardioplegia (29 degrees C) avoids the delayed recovery of cardiac function and metabolism associated with cold cardioplegia (15 degrees C) and reduces the anaerobic metabolism seen with warm (37 degrees C) cardioplegia. We compared two techniques that combine antegrade and retrograde tepid cardioplegia: alternate and simultaneous. METHODS: Sixty patients undergoing elective isolated coronary artery bypass grafting were randomized to receive near continuous tepid retrograde and either intermittent antegrade cardioplegia (the alternate technique) or antegrade cardioplegia with the solution delivered concurrently through each completed vein graft (the simultaneous technique). RESULTS: Myocardial lactate extraction was greater after crossclamp release following simultaneous than alternate cardioplegia. Postoperative ventricular function was better after alternate than simultaneous cardioplegia. CONCLUSION: Both techniques permitted rapid postoperative recovery of myocardial metabolism and ventricular function. However, simultaneous cardioplegia was simpler and did not require deairing the aortic root between antegrade infusions.


Assuntos
Parada Cardíaca Induzida/métodos , Adulto , Idoso , Anaerobiose , Aorta , Temperatura Corporal , Ponte Cardiopulmonar , Temperatura Baixa , Ponte de Artéria Coronária , Vasos Coronários/fisiopatologia , Procedimentos Cirúrgicos Eletivos , Temperatura Alta , Humanos , Lactatos/metabolismo , Masculino , Pessoa de Meia-Idade , Reperfusão Miocárdica , Miocárdio/metabolismo , Estudos Prospectivos , Resultado do Tratamento , Resistência Vascular , Função Ventricular
9.
Ann Thorac Surg ; 62(3): 654-60; discussion 660-1, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8783989

RESUMO

BACKGROUND: Transplantation of cultured cardiomyocytes into myocardial scar tissue may prevent heart failure. METHODS: Scar tissue was produced in the left ventricular free wall of 15 rats (weight, 450 g) by cryoinjury. Seven animals had operation only and survived for 8 weeks (sham group). Four weeks after cryoinjury, cultured fetal rat cardiomyocytes or culture medium was injected into the scar tissue of transplantation (n = 5) and control (n = 5) animals, respectively. Five other rats were sacrificed for scar assessment. Eight weeks after cryoinjury heart function in the transplantation, control, and sham groups was measured using a Langendorff preparation. Histologic studies were performed to quantify the extent of the scar and the transplanted cells. RESULTS: Four weeks after cryoinjury, 36% +/- 4% (mean +/- 1 standard error) of the left ventricular free wall surface area was scar tissue. At 8 weeks, the scar size had increased (p < 0.01) to 55% +/- 3% in the control group. Although the scar size (43% +/- 2%) in the transplantation group at 8 weeks was not significantly different from that at 4 weeks, it was less (p < 0.05) than that in the control group. Hearts in the sham group had no scar tissue. The transplanted cardiomyocytes had formed cardiac tissue within the myocardial scar. Systolic and developed pressures in the transplantation group hearts were greater (p = 0.0001) than in the control group hearts but less (p < 0.01) than those in the sham group hearts. CONCLUSIONS: The transplanted cardiomyocytes formed cardiac tissue in the myocardial scar, limited scar expansion, and improved heart function compared with findings in the control hearts.


Assuntos
Transplante de Células , Coração Fetal/citologia , Transplante de Tecido Fetal , Ventrículos do Coração/cirurgia , Coração/fisiopatologia , Animais , Células Cultivadas , Circulação Coronária , Frequência Cardíaca , Masculino , Miocárdio/citologia , Ratos , Ratos Sprague-Dawley
10.
Circ Res ; 78(2): 283-8, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8575072

RESUMO

Recent studies have demonstrated the feasibility of transplanting fetal mouse cardiomyocytes into the hearts of adult syngeneic mice. However, the function of the transplanted cardiomyocytes and their capacity to survive in fibrous connective tissue were not assessed. In the present study, we evaluated the viability and contractility of transplanted fetal and neonatal rat cardiomyocytes in the connective tissue of the adult rat hindlimb. Purified fetal or neonatal rat cardiomyocytes were cultured. These cells contained sarcomeres, formed junctions composed of desmosomes and fascia adherens, and contracted regularly and spontaneously. A fetal or neonatal cardiomyocyte suspension was injected into the subcutaneous tissue of adult rat hindlimbs. Cyclosporin A (5 mg/kg) was administered subcutaneously daily for the 3-month duration of the study, at which time the animals were killed. The transplanted cardiomyocytes formed 'tissue' in vivo that increased in size for the first 2 weeks and remained the same size at the third week. The tissue derived from the transplanted fetal cardiomyocytes contracted spontaneously at a rate of 73 +/- 12 bpm, and that from the neonatal cardiomyocytes contracted at a rate of 43 +/- 21 bpm. The electrocardiogram was similar to that seen in myocardium with an idioventricular rhythm. Histologically, the tissue appeared to be cardiac muscle with sarcomeres. Angiogenesis occurred in the cardiomyocyte graft. In summary, a cell suspension of cultured fetal and neonatal rat cardiomyocytes transplanted into the adult rat hindlimb formed contractile cardiac tissue in the subcutaneous connective tissue.


Assuntos
Transplante de Células , Sobrevivência de Enxerto , Miocárdio/citologia , Animais , Sobrevivência Celular , Células Cultivadas , Feminino , Transplante de Tecido Fetal , Masculino , Microscopia Eletrônica , Contração Miocárdica , Miocárdio/ultraestrutura , Gravidez , Ratos , Ratos Sprague-Dawley
11.
J Thorac Cardiovasc Surg ; 110(3): 800-12, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7564449

RESUMO

Seventy-five patients undergoing coronary artery bypass grafting were randomized to receive warm antegrade (N = 25), warm retrograde (N = 25), or a combination of warm antegrade and retrograde (N = 25) delivery of blood cardioplegic solution. Myocardial oxygen utilization, lactate and acid metabolism, and adenine nucleotides and their degradation products were measured during the operation and cardiac function was assessed postoperatively. Warm retrograde delivery of cardioplegic solution increased lactate and acid release during cardioplegia and reperfusion, decreased left ventricular adenosine triphosphate concentrations, and reduced the washout of adenine nucleotide degradation products from both left and right ventricles. Warm antegrade delivery of cardioplegic solution resulted in less lactate and acid release during cardioplegia but more lactate accumulated in the territory of the left anterior descending artery during the crossclamp period. Intermittent antegrade delivery of the cardioplegic solution during combination cardioplegia washed out lactate and acid, which suggested inhomogeneous delivery of the cardioplegic solution during continuous retrograde cardioplegia. Combination cardioplegia best preserved adenosine triphosphate in the left ventricle and resulted in the best postoperative left and right ventricular function. A combination of intermittent antegrade and continuous retrograde delivery of cardioplegic solution provided better myocardial protection than either antegrade or retrograde delivery of cardioplegic solution alone.


Assuntos
Soluções Cardioplégicas/farmacocinética , Parada Cardíaca Induzida , Nucleotídeos de Adenina/metabolismo , Adulto , Idoso , Sangue , Estimulação Cardíaca Artificial , Ponte de Artéria Coronária , Doença das Coronárias/metabolismo , Doença das Coronárias/fisiopatologia , Doença das Coronárias/cirurgia , Creatina Quinase/metabolismo , Feminino , Coração/fisiopatologia , Parada Cardíaca Induzida/métodos , Ventrículos do Coração/metabolismo , Hemodinâmica , Humanos , Concentração de Íons de Hidrogênio , Isoenzimas , Lactatos/metabolismo , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Oxigênio/metabolismo , Perfusão/métodos , Estudos Prospectivos , Temperatura
12.
Ann Thorac Surg ; 59(3): 723-9, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7887719

RESUMO

To determine the optimal temperature for the combination of antegrade and retrograde cardioplegia, 42 patients undergoing coronary artery bypass grafting were randomized to receive cold (9 degrees C; n = 14), tepid (29 degrees C; n = 14), or warm (37 degrees C; n = 14) blood cardioplegia delivered continuously retrograde and intermittently antegrade. Myocardial oxygen utilization, lactate and acid metabolism, and coronary vascular resistance were measured during the operation and cardiac function was assessed postoperatively. Myocardial oxygen consumption, lactate release and acid release were greatest with warm, intermediate with tepid, and least with cold cardioplegia (p = 0.0001). However, washout of lactate and acid at the time of cross-clamp release was reduced (p = 0.022) with tepid or cold compared with warm cardioplegia. Early postoperative left ventricular function was best preserved (p = 0.01) after tepid than after cold or warm combination cardioplegia. These results suggest that tepid combination cardioplegia reduced metabolic demands but permitted immediate recovery of cardiac function. This technique may provide better myocardial protection than cold or warm combination cardioplegia.


Assuntos
Ponte de Artéria Coronária/métodos , Doença das Coronárias/cirurgia , Parada Cardíaca Induzida/métodos , Temperatura , Idoso , Análise de Variância , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Circulação Coronária , Doença das Coronárias/metabolismo , Doença das Coronárias/fisiopatologia , Feminino , Frequência Cardíaca , Humanos , Cuidados Intraoperatórios , Lactatos/metabolismo , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Cuidados Pós-Operatórios , Resistência Vascular , Função Ventricular Esquerda
13.
Ann Thorac Surg ; 58(4): 961-71, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7944817

RESUMO

Seventy-two patients undergoing coronary artery bypass grafting were randomized to receive cold (8 degrees C) antegrade or retrograde, tepid (29 degrees C) antegrade or retrograde, or warm (37 degrees C) antegrade or retrograde blood cardioplegia (n = 12 in each group). Myocardial oxygen utilization as well as lactate and acid metabolism were assessed intraoperatively and cardiac function was assessed postoperatively. Myocardial oxygen consumption and anaerobic lactate release were greatest during warm, intermediate during tepid, and least during cold cardioplegic arrest. Myocardial oxygen consumption and lactate release were underestimated during retrograde cardioplegia because of contamination of aortic root samples. Warm retrograde and tepid retrograde cardioplegia resulted in greater lactate and acid washout with reperfusion. Left ventricular stroke work indices were greater after warm antegrade and tepid antegrade cardioplegia than after cold antegrade cardioplegia, and right ventricular stroke work indices were greatest after warm antegrade cardioplegia. Warm antegrade cardioplegia increased aerobic metabolism during and after cardioplegia and preserved left and right ventricular function. Tepid antegrade cardioplegia reduced anaerobic lactate and acid release during arrest and preserved cardiac function.


Assuntos
Ponte de Artéria Coronária/métodos , Parada Cardíaca Induzida/métodos , Temperatura , Adulto , Idoso , Doença das Coronárias/metabolismo , Doença das Coronárias/cirurgia , Creatina Quinase/metabolismo , Feminino , Hemodinâmica , Humanos , Isoenzimas , Lactatos/metabolismo , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Consumo de Oxigênio , Estudos Prospectivos
14.
J Thorac Cardiovasc Surg ; 108(2): 302-10, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8041178

RESUMO

BACKGROUND: Free radical lipid peroxidation contributes to the abnormal metabolism and ventricular function frequently seen after cardiac operations. Antioxidants may improve metabolic and functional recovery. METHODS: A prospective, randomized, double-blind clinical trial was conducted to determine the effects of vitamin E (alpha-tocopherol) (n = 14) or a corn oil placebo (n = 14) in patients undergoing elective coronary bypass operations. The RRR-alpha-tocopheryl acetate doubled the alpha-tocopherol levels in the heart. Myocardial metabolism and ventricular function were assessed after the operation. RESULTS: Atrial pacing induced myocardial lactate production in the control patients but lactate consumption in the alpha-tocopherol-treated patients on bypass 25 minutes after crossclamp release. Left ventricular stroke work indices were higher, at similar ventricular volumes, in the alpha-tocopherol-treated group, which indicates improved preload recruitable stroke work, and diastolic compliance was greater 4 hours after the operation. The postoperative creatine kinase cardiac isoenzyme levels were lower in the patients who received alpha-tocopherol. CONCLUSIONS: Pretreatment with alpha-tocopherol sufficient to double the myocardial concentrations had a small but significant metabolic and functional effect after elective coronary bypass operations when compared with placebo. These results do not justify pretreatment of low-risk patients, but they do justify an evaluation in high-risk patients.


Assuntos
Ponte de Artéria Coronária , Miocárdio/metabolismo , Pré-Medicação , Função Ventricular/efeitos dos fármacos , Vitamina E/uso terapêutico , Adulto , Idoso , Creatina Quinase/sangue , Relação Dose-Resposta a Droga , Método Duplo-Cego , Coração/efeitos dos fármacos , Humanos , Isoenzimas , Lactatos/metabolismo , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Miocárdio/química , Consumo de Oxigênio , Estudos Prospectivos , Vitamina E/análise , Vitamina E/farmacologia
15.
J Thorac Cardiovasc Surg ; 107(2): 510-9, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8302071

RESUMO

Retrograde delivery of warm blood cardioplegia may improve nutrient cardioplegic flow beyond coronary obstructions, but may not adequately perfuse the right ventricle and the posterior left ventricle. To determine the optimal flow rate for warm retrograde cardioplegia, we assessed 62 patients undergoing elective coronary artery bypass in two studies. In the low flow study, administration of 50 ml/min (n = 9), 75 ml/min (n = 11), or 100 ml/min (n = 7) was associated with high lactate production and oxygen extraction during cardioplegic administration. At 50 minutes of cardioplegic arrest, the coronary venous effluent pH was low in all groups. In the high flow study, 30 patients all received flow rates of 100, 200, and 300 ml/min in randomized order during the crossclamp period. In addition, five patients received cardioplegia at a rate of 500 ml/min for the duration of the crossclamp period. Administration of 200 ml/min or higher minimized lactate production and maintained coronary venous pH within the physiologic range, but flows of 300 ml/min or higher did not increase oxygen use or reduce lactate or acid production. Patients in the low flow groups had significantly greater myocardial lactate release during cardioplegic infusion and after removal of the crossclamp than the high flow group. Warm retrograde cardioplegia should be delivered at flow rates of at least 200 ml/min during elective coronary artery bypass operations.


Assuntos
Soluções Cardioplégicas/administração & dosagem , Parada Cardíaca Induzida/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Perfusão/métodos , Adulto , Idoso , Sangue , Ponte de Artéria Coronária , Feminino , Humanos , Lactatos/metabolismo , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Traumatismo por Reperfusão Miocárdica/metabolismo , Oxigênio/sangue , Consumo de Oxigênio , Temperatura , Resultado do Tratamento
16.
Ann Thorac Surg ; 56(5): 1020-8, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8239794

RESUMO

One hundred seven patients undergoing coronary artery bypass grafting were randomized to receive warm antegrade (n = 21), warm retrograde (n = 22), cold antegrade (n = 20), cold retrograde (n = 22), or intermittent cold antegrade (n = 22) blood cardioplegia. Myocardial oxygen consumption and lactate production, adenine nucleotides, and adenine nucleotide degradation products were measured during the operation, and creatine kinase-MB release was assessed postoperatively. Warm cardioplegia resulted in greater myocardial lactate production than cold cardioplegia (p = 0.048). Retrograde cardioplegia was associated with greater lactate production than antegrade cardioplegia (p = 0.015). Adenosine triphosphate depletion was similar among groups. However, poorly diffusible metabolites of adenosine triphosphate accumulated to the greatest extent in the intermittent cold group. Levels of hypoxanthine were highest after warm retrograde cardioplegia. Operative mortality and morbidity were low and were not different among groups. In summary, none of the five techniques of cardioplegia evaluated in this study was able to completely prevent myocardial ischemia. Anaerobic lactate production was minimized with cold cardioplegia and with antegrade cardioplegic delivery. Hypothermia may have impaired regeneration of adenosine triphosphate, however, particularly in association with inadequate or intermittent cardioplegic flow.


Assuntos
Ponte de Artéria Coronária/métodos , Parada Cardíaca Induzida/métodos , Coração/fisiopatologia , Isquemia Miocárdica/prevenção & controle , Miocárdio/metabolismo , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Velocidade do Fluxo Sanguíneo , Transfusão de Sangue Autóloga , Creatina Quinase/sangue , Feminino , Hemodinâmica , Humanos , Concentração de Íons de Hidrogênio , Hipotermia Induzida/métodos , Isoenzimas , Lactatos/metabolismo , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Reperfusão Miocárdica/métodos , Consumo de Oxigênio , Período Pós-Operatório , Temperatura , Fatores de Tempo , Resultado do Tratamento
17.
J Thorac Cardiovasc Surg ; 105(5): 833-43; discussion 843-4, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8487562

RESUMO

Warm cardioplegia produced by essentially continuous infusion has been used as an alternative to traditional cold intermittent infusion techniques during cardiac surgery, but its effects on postoperative left ventricular function have not been defined. We performed a randomized clinical trial to assess the effects of warm and cold blood cardioplegia on load-independent indices of ventricular function. Fifty-three patients were randomized to warm (n = 27) or cold (n = 26) cardioplegia. Myocardial oxygen consumption, lactate production, adenine nucleotides, and adenine nucleotide degradation products were measured during cardioplegia and reperfusion. In 13 patients per group, pressure-volume loops were constructed and ventricular function was assessed 3 hours after the operation. Warm cardioplegia resulted in greater myocardial lactate production but improved recovery of oxygen consumption during reperfusion. Depletion of adenosine triphosphate was similar between groups, but total adenine nucleotides (adenosine triphosphate + adenosine diphosphate + adenosine monophosphate) fell further during warm cardioplegia. Cold cardioplegia was associated with an accumulation of adenosine diphosphate and adenosine monophosphate. Creatine kinase MB isoenzyme release was reduced in the warm group. Three hours after the operation, end-systolic elastance and preload-recruitable stroke work index were increased after warm cardioplegia, and early diastolic relaxation was also increased. Increased systolic function after warm cardioplegia may have been related to improved myocardial protection, elevated arterial lactate concentrations, or increased circulating catecholamine levels. Altered diastolic compliance in the warm group may reflect greater active relaxation during early diastolic filling.


Assuntos
Sangue , Parada Cardíaca Induzida/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Função Ventricular Esquerda/fisiologia , Nucleotídeos de Adenina/metabolismo , Soluções Cardioplégicas , Ponte de Artéria Coronária , Feminino , Humanos , Lactatos/metabolismo , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Consumo de Oxigênio/fisiologia , Temperatura
18.
Circulation ; 86(5 Suppl): II377-84, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1424027

RESUMO

BACKGROUND: Although normothermic cardioplegia has been used with acceptable clinical results, no studies have previously been performed to determine the metabolic consequences of these various techniques of myocardial protection. Therefore, we have performed a randomized clinical trial to assess the effects of three cardioplegic techniques on myocardial metabolic recovery. METHODS AND RESULTS: Seventy-four patients undergoing coronary artery bypass graft surgery were randomized to receive normothermic antegrade blood cardioplegia (n = 25), normothermic retrograde blood cardioplegia (n = 23), or intermittent cold antegrade blood cardioplegia (n = 26). Myocardial oxygen consumption and lactate production, adenine nucleotides, and adenine nucleotide degradation products were measured during the operation, and cardiac creatine kinase isoenzyme (CK-MB) release was assessed after surgery. Warm antegrade cardioplegia maximized myocardial oxygen consumption during cardioplegic delivery. Postoperative CK-MB release was less after warm antegrade cardioplegia, but the difference was not statistically significant. Warm retrograde cardioplegia resulted in the greatest degree of anaerobic lactate production but did not increase morbidity and mortality. Perioperative myocardial infarctions and postoperative low-output syndrome were most common after cold cardioplegia, but this trend was not statistically significant. During warm antegrade cardioplegia, adenosine triphosphate (ATP) was metabolized to diffusible precursors, which were washed out during cardioplegic infusion. Warm retrograde cardioplegia produced a breakdown of ATP to inosine and hypoxanthine, small molecules that accumulated during the cross-clamp period and were not washed out, perhaps because of inadequate perfusion with retrograde delivery. During cold cardioplegia, ATP was dephosphorylated, and adenosine diphosphate, adenosine monophosphate, and adenosine accumulated. These compounds were not regenerated to ATP but were not washed out of myocytes because they are large anionic molecules. CONCLUSIONS: Intermittent cold cardioplegia inhibited mitochondrial function but prevented the degradation of adenine nucleotides. Warm antegrade cardioplegia had the greatest myocardial oxygen consumption, and warm retrograde cardioplegia had the greatest anaerobic lactate production. There were no differences in clinical outcomes between cardioplegic groups.


Assuntos
Parada Cardíaca Induzida/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Trifosfato de Adenosina/metabolismo , Sangue , Ponte de Artéria Coronária , Creatina Quinase/metabolismo , Feminino , Humanos , Lactatos/metabolismo , Ácido Láctico , Masculino , Pessoa de Meia-Idade , Mitocôndrias Cardíacas/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Consumo de Oxigênio/fisiologia , Temperatura
19.
J Thorac Cardiovasc Surg ; 104(3): 817-24, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1325014

RESUMO

Cardiac storage for transplantation is currently limited to 6 hours. To better understand the metabolic changes that occur during hypothermic (4 degrees C) storage, we monitored the morphologic and metabolic changes in the canine myocardium at 0, 12, and 24 hours of storage in University of Wisconsin solution. Attempts to isolate cardiac mitochondria resulted in a progressive decline in the yield (milligrams of mitochondria per gram of heart tissue), which decreased (p less than 0.05) from 9.2 +/- 0.4 at 0 hours (control) to 4.0 +/- 0.3 after 12 hours and further decreased (p less than 0.05) to 1.9 +/- 0.2 after 24 hours of cold storage. Mitochondrial state 3 respiration fell to 64% of control after 12 hours and 28% of control after 24 hours of cold storage (p less than 0.05). Citrate synthetase activity, but not cytochrome C oxidase activity, was significantly depressed after 12 and 24 hours of cold storage. Adenosine triphosphate content decreased to 67% of control after 12 hours and 50% of control after 24 hours. After 12 hours of storage, sufficient adenosine diphosphate and monophosphate were present to permit some restoration of adenosine triphosphate, provided mitochondrial function was normal after transplantation. However, restoration of mitochondrial function and adenosine triphosphate levels sufficient to support myocardial contractility was unlikely after 24 hours of storage. This study suggests that a return of adequate cardiac function after transplantation may be possible after 12 hours of cold storage in University of Wisconsin solution but not after 24 hours of cold storage.


Assuntos
Criopreservação , Transplante de Coração , Mitocôndrias Cardíacas/fisiologia , Miocárdio/metabolismo , Preservação de Órgãos , Trifosfato de Adenosina/análise , Animais , Citrato (si)-Sintase/análise , Cães , Complexo IV da Cadeia de Transporte de Elétrons/análise , Mitocôndrias Cardíacas/enzimologia , Contração Miocárdica , Consumo de Oxigênio , Soluções , Fatores de Tempo
20.
Circulation ; 84(5 Suppl): III380-8, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1934434

RESUMO

A prospective randomized controlled trial was performed to determine optimal flow rates and hemoglobin concentrations for continuous normothermic blood cardioplegia and to compare warm heart surgery with standard intermittent cold blood cardioplegia. Thirty-five patients received intermittent cold blood cardioplegia, low hemoglobin low flow, low hemoglobin high flow, high hemoglobin low flow, or high hemoglobin high flow warm blood cardioplegia (seven patients per group: low hemoglobin, 50 g/l; high hemoglobin, 80 g/l; low flow, less than 80 ml/min; high flow, greater than 80 ml/min). Hypothermia resulted in a significantly greater accumulation of ADP and AMP during cross clamp, consistent with impaired mitochondrial function. Low hemoglobin low flow warm blood cardioplegia increased myocardial oxygen consumption and coronary sinus blood flow after cross clamp release, and also decreased lactate consumption. Postoperative myocardial performance and diastolic compliance were reduced in low hemoglobin low flow warm patients, and diastolic compliance was increased with high hemoglobin high flow warm blood cardioplegia when compared with cold patients. In this study, continuous normothermic cardioplegia was safe when delivered at 80 ml/min or greater, with a hemoglobin concentration of at least 80 g/l, affording myocardial metabolic and functional recovery comparable to that found after intermittent cold blood cardioplegia.


Assuntos
Sangue , Ponte de Artéria Coronária , Parada Cardíaca Induzida/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Soluções Cardioplégicas , Temperatura Baixa , Hemoglobinas/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Reperfusão Miocárdica/métodos , Miocárdio/metabolismo , Estudos Prospectivos
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