RESUMO
We have determined the extent of fragment X formation during thrombolytic therapy by integration over time of the plasma fibrinopeptide B beta 1-42 concentration. This peptide is quantitatively released when fragment X is formed by plasmin action on fibrinogen or fibrin I. In response to streptokinase (SK) and rt-PA, 264 +/- 54 and 95 +/- 12 mg/dl respectively of fibrinogen was converted to fragment X. By immunoblotting, fragment X was demonstrated as early as 5 min after SK and 30 min after rt-PA, and was still evident 24 h after treatment. Patients treated with SK showed extensive further plasmin degradation of fragment X to fragments Y and D. Thus fragment X concentrations tend to be more similar in the two groups than would be expected from the extent of fibrinogen breakdown. Fragment X forms clots, but these have lower tensile strength and are more susceptible to further plasmin lysis than clots of fibrin. Thus the similar bleeding observed in the two treatment groups might be a reflection of their similar plasma fragment X concentrations.
Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/biossíntese , Fibrinolíticos/uso terapêutico , Estreptoquinase/uso terapêutico , Ativador de Plasminogênio Tecidual/uso terapêutico , Fibrinolisina/metabolismo , Fibrinopeptídeo B/metabolismo , Transtornos Hemorrágicos/prevenção & controle , Humanos , Infarto do Miocárdio/tratamento farmacológico , Proteínas Recombinantes/uso terapêuticoRESUMO
BACKGROUND: alpha(v)beta(3)-Integrin receptors are upregulated in atherosclerotic arteries and play a key role in smooth muscle cell and possibly inflammatory cell migration. We hypothesized that after balloon angioplasty (BA) of atherosclerotic arteries, selective inhibition of the alpha(v)beta(3)-receptor by XT199, a small-molecule, non-peptide-selective alpha(v)beta(3)-receptor antagonist, would reduce restenosis. METHODS AND RESULTS: After induction of focal atherosclerosis, rabbits underwent femoral BA and received XT199 (2.5 mg/kg IV bolus plus 2.5 mg. kg(-1). d(-1) IV; n=19) or vehicle (n=20) for 14 days. At 28 days after BA, the XT199 group had a larger lumen (0.75+/-0.26 versus 0.57+/-0.20 mm(2), P=0.03) and a smaller neointimal area (0.49+/-0.18 versus 0.68+/-0.25 mm(2), P=0.01) than the vehicle group. Angiographic analysis confirmed a 30% to 40% reduction in restenosis. Arteries harvested at 28 days after BA did not show a reduction in intima plus media smooth muscle cell content but did show a 50% reduction in macrophage cell density in the XT199 group (716+/-452 versus 1458+/-989 cells/mm(2), P<0.006). Neovessel density at 28 days was also reduced (23+/-42 versus 58+/-46 vessel cross sections/mm(2), P<0.02). Early after BA (ie, 3 to 7 days), there was a decrease in intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression, indicative of a reduction in vascular cell activation. CONCLUSIONS: Selective alpha(v)beta(3)-receptor blockade for 14 days after BA in the focally atherosclerotic rabbit significantly reduced restenosis and limited macrophage infiltration and neovascularization in the vessel wall.
Assuntos
Arteriopatias Oclusivas/prevenção & controle , Arteriosclerose/terapia , Macrófagos/efeitos dos fármacos , Receptores de Vitronectina/antagonistas & inibidores , Actinas/análise , Angioplastia com Balão , Animais , Arteriopatias Oclusivas/patologia , Arteriosclerose/patologia , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/metabolismo , Colesterol/sangue , Relação Dose-Resposta a Droga , Artéria Femoral/efeitos dos fármacos , Artéria Femoral/metabolismo , Artéria Femoral/patologia , Imidazóis/farmacologia , Imuno-Histoquímica , Molécula 1 de Adesão Intercelular/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/metabolismo , Macrófagos/patologia , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Coelhos , Receptores de Vitronectina/metabolismo , Recidiva , Fatores de Tempo , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/metabolismo , Túnica Íntima/patologia , Túnica Média/efeitos dos fármacos , Túnica Média/metabolismo , Túnica Média/patologia , Molécula 1 de Adesão de Célula Vascular/efeitos dos fármacos , Molécula 1 de Adesão de Célula Vascular/metabolismoRESUMO
BACKGROUND: Determination of fractional flow reserve (FFR) has been proposed as a means to assess stent deployment. In this prospective, multicenter trial, we evaluate the use of FFR to optimize stenting by comparing it with standard intravascular ultrasound (IVUS) criteria. METHODS AND RESULTS: Eighty-four stable patients with isolated coronary lesions underwent coronary stent deployment starting at 10 atm and increased serially by 2 atm until the FFR was >/=0.94 or 16 atm was achieved. IVUS was then performed. FFR was measured with a coronary pressure wire with intracoronary adenosine to induce hyperemia. The diagnostic characteristics of an FFR <0.94 to predict suboptimal stent expansion by IVUS, defined in both absolute and relative terms, were calculated. Over a range of IVUS criteria, the highest sensitivity, specificity, and predictive accuracy of FFR were 80%, 30%, and 42%, respectively. Receiver operator characteristic analysis defined an optimal FFR cut point at >/=0.96; at this threshold, the sensitivity, specificity, and predictive accuracy of FFR were 75%, 58%, and 62%, respectively (P=0.03 for comparison of predictive accuracy, P=0.01 for concordance between FFR and IVUS). The negative predictive value was 88%. Significantly better diagnostic performance was achieved in a subgroup that received higher doses (>30 microgram) of intracoronary adenosine during pressure measurements, suggesting that FFR might be overestimated in the other group. CONCLUSIONS: A fractional flow reserve <0.96, measured after stent deployment, predicts a suboptimal result based on validated intravascular ultrasound criteria; however, an FFR >/=0.96 does not reliably predict an optimal stent result. Higher doses of intracoronary adenosine than previously used to measure FFR improve these results.
Assuntos
Angioplastia Coronária com Balão/métodos , Implante de Prótese Vascular/métodos , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/cirurgia , Ultrassonografia de Intervenção , Adenosina , Velocidade do Fluxo Sanguíneo , Angiografia Coronária , Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Vasos Coronários/cirurgia , Feminino , Humanos , Funções Verossimilhança , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Stents , Resultado do TratamentoRESUMO
This study was designed to examine the effect of increases in the partial pressure of carbon dioxide (PCO2) in coronary artery blood on coronary blood flow, coronary reactive hyperemia and the coronary response to intracoronary adenosine administration. The left anterior descending coronary artery was cannulated and perfused over a wide range of perfusion pressure (P) and flow (F) with blood equilibrated with 0 to 40% carbon dioxide in 16 open chest dogs. Increases in coronary artery PCO2 from 20 +/- 2 to 93 +/- 8 to 211 +/- 22 mm Hg (mean +/- SEM) increased the coronary flow from 28 +/- 3 to 68 +/- 16 to 87 +/- 22 ml/min, respectively, at a perfusion pressure of 60 mm Hg and from 49 +/- 6 to 139 +/- 30 to 206 +/- 48 ml/min, respectively, at a perfusion pressure of 100 mm Hg. Coronary reactive hyperemia following a 30 second coronary perfusion line occlusion and the response to an intracoronary bolus of adenosine (60 micrograms) were prominent at a low PCO2 but absent at a high PCO2. Beta-adrenergic blockade did not abolish the increase in coronary flow that occurred at increased PCO2. Thus, progressive elevations of regional coronary PCO2 produced substantial increases in coronary blood flow and maximal or near maximal coronary vasodilation.
Assuntos
Dióxido de Carbono/fisiologia , Circulação Coronária , Frequência Cardíaca , Adenosina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Cães , Feminino , Frequência Cardíaca/efeitos dos fármacos , Masculino , Pressão Parcial , Propranolol/farmacologia , Troca Gasosa Pulmonar , Resistência Vascular/efeitos dos fármacosRESUMO
The effect of balloon size on the success of coronary angioplasty was studied to develop quantitative criteria for optimal selection of balloon size. Coronary dimensions of 165 stenotic lesions were measured by computer-assisted cinevideodensitometry in 120 patients who had undergone angioplasty with a balloon selected by visual estimates. Cross-sectional areas and diameters of normal and stenotic arterial segments were measured before and after angioplasty by a previously validated cinevideodensitometric technique. The diameter of the inflated balloon compared with that of the normal arterial segment was expressed as a ratio for sizing balloons. Oversized balloons with a ratio greater than 1.3 (n = 35) caused a high (37%) incidence of dissection, with three severely compromised arterial lumens. Undersized balloons with a ratio less than 0.9 (n = 29) often resulted in significant (greater than 50% diameter stenosis) residual stenotic lesions (21%) and a significantly (p less than 0.05) higher rate of repeat angioplasty for restenosis. Selection of balloon sizes with ratios in the 0.9 to 1.3 range (n = 101) resulted in a low (4%) incidence of dissection with few patients (3%) having significant residual stenosis. Mean residual stenosis (percent diameter reduction) was most severe for undersized (35.0 +/- 18%) or oversized (23.1 +/- 19%) balloons and least severe for balloons with a ratio of 0.9 to 1.3 (18.7 +/- 14%) (p less than 0.001). Repeat angioplasty for restenosis was more frequently required (p less than 0.05) for lesions dilated with undersized balloons. Thus, selection of angioplasty balloons that approximate or slightly exceed the diameter of the normal arterial diameter yields optimal angiographic results with minimal dissections and minimal residual stenotic lesions.
Assuntos
Angioplastia com Balão/instrumentação , Doença das Coronárias/terapia , Cineangiografia , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/cirurgia , Constrição Patológica/terapia , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/cirurgia , Densitometria , Diagnóstico por Computador , HumanosRESUMO
OBJECTIVES: We hypothesized that bolus intravenous nitroglycerin would be an afterload-reducing agent in patients with excessive initial afterload for their level of left ventricular systolic function. Conversely, bolus intravenous nitroglycerin should be a preload-reducing agent in patients without excessive initial afterload. BACKGROUND: Although nitroglycerin has both preload- and afterload-reducing actions, methods to predict its predominant site of action in an individual patient have not been previously described. METHODS: Left ventricular pressure-volume relations were recorded with micromanometer and conductance catheters during bolus injection of intravenous nitroglycerin in 27 patients with both normal left ventricular systolic function and varying degrees of congestive heart failure. Preload was determined by end-diastolic volume, afterload by effective arterial elastance, left ventricular systolic function by end-systolic elastance and coupling of afterload and ventricular function by the ratio of effective arterial elastance to end-systolic elastance (Ea/Ees ratio). An Ea/Ees ratio > 1 was defined as excessive afterload for the level of ventricular function. RESULTS: Patients with an initial Ea/Ees ratio < 1 (Group 1) constituted a group of normotensive patients with intact ventricular function who exhibited a predominant reduction in preload in response to intravenous nitroglycerin. Those with an initial Ea/Ees ratio > 1 and normal or mildly depressed ventricular function (Group 2a) constituted a group of patients, most of whom were hypertensive, who exhibited a predominant afterload reduction. Finally, those with an initial Ea/Ees ratio > 1 and abnormal ventricular function (Group 2b) constituted a group of patients with clinical congestive heart failure who exhibited both preload and afterload reduction but a predominant afterload reduction because stroke volume increased. CONCLUSIONS: Patients with normal arterial elastance and ventricular function respond to nitroglycerin with a predominant preload reduction, whereas patients with either excessive arterial elastance or abnormal ventricular function respond with a predominant afterload reduction.
Assuntos
Insuficiência Cardíaca/fisiopatologia , Nitroglicerina/farmacologia , Resistência Vascular/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos , Análise de Variância , Pressão Sanguínea , Estudos de Casos e Controles , Feminino , Frequência Cardíaca , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Nitroglicerina/administração & dosagem , Volume SistólicoRESUMO
The influence of contrast media on thrombus formation during percutaneous transluminal coronary angioplasty was assessed in 124 consecutive patients undergoing coronary angioplasty and receiving either ionic (n = 57) (Group I) or nonionic (n = 67) (Group II) contrast medium. The presence of thrombus was assessed by qualitative analysis of angiograms in identical pre- and postangioplasty projections by four observers who had no knowledge of other data. Quantitation of stenosis severity before and after angioplasty and qualitative analysis of lesion eccentricity and complexity and of the presence of dissection were also performed. Although the baseline clinical characteristics of the two groups (including presenting syndromes and procedural and angiographic variables) did not differ, more patients in Group II than Group I developed new thrombus during coronary angioplasty (18% vs. 4%, p less than 0.02). In particular, patients with a presenting syndrome of recent myocardial infarction or rest angina, or both, and patients with an eccentric coronary plaque were more likely to develop new thrombus if they received nonionic than if they received ionic contrast medium (p less than 0.05). Patients with new thrombus formation and patients with thrombus present both before and after angioplasty had a high incidence of acute procedural complications (36% and 23%, respectively). Patients in Groups I and II had a similar incidence of ischemic events during follow-up.
Assuntos
Angioplastia Coronária com Balão , Meios de Contraste/efeitos adversos , Trombose Coronária/induzido quimicamente , Angiografia Coronária , Doença das Coronárias/terapia , Trombose Coronária/epidemiologia , Diatrizoato/efeitos adversos , Diatrizoato de Meglumina/efeitos adversos , Combinação de Medicamentos , Feminino , Humanos , Incidência , Iopamidol/efeitos adversos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Concentração Osmolar , Estudos RetrospectivosRESUMO
Endothelial activation and leukocyte recruitment are early events in atherosclerosis and the vascular response to injury. Adenosine has anti-inflammatory effects on leukocytes and endothelial cells mediated through its A(2A) receptor. We tested the hypothesis that A(2A) activation would reduce inflammation and neointimal formation in a murine carotid ligation model. Before injury, mice were randomized to a 7-day subcutaneous infusion of a specific A(2A) receptor agonist (ATL-146e, 0.004 microg/kg per minute), vehicle control, ATL-146e plus ZM241385 (a selective A(2A) antagonist), or ZM241385 alone. Leukocyte recruitment and adhesion molecule expression were assessed at early time points, and the neointimal area was measured at 14 and 28 days after injury. Compared with control mice, ATL-146e-treated mice had significantly less neutrophil and macrophage recruitment and vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and P-selectin expression in the first 7 days after injury. Neointimal area was markedly and persistently reduced by 80% at 14 and 28 days, despite termination of ATL infusion at 7 days. ATL-146e+ZM241385-treated and ZM241385-treated animals had neointimal areas similar to those of control animals, confirming that the observed effects of ATL-146e were mediated specifically by the A(2A) receptor. These data demonstrate that novel stimulation of adenosine A(2A) receptors can inhibit early inflammatory processes that are important in neointimal formation after vascular injury.
Assuntos
Arteriosclerose/tratamento farmacológico , Lesões das Artérias Carótidas/tratamento farmacológico , Receptores Purinérgicos P1/metabolismo , Animais , Arteriosclerose/etiologia , Arteriosclerose/patologia , Lesões das Artérias Carótidas/etiologia , Lesões das Artérias Carótidas/patologia , Moléculas de Adesão Celular/metabolismo , Feminino , Inflamação , Contagem de Leucócitos , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos , Antagonistas de Receptores Purinérgicos P1 , Receptor A2A de Adenosina , Triazinas/farmacologia , Triazóis/farmacologiaRESUMO
Previous studies investigating the effect of hypertonic mannitol infusion during coronary occlusion have yielded conflicting results. The present study investigated the effect of hypertonic mannitol infusion on regional myocardial blood flow (microsphere technique), a metabolic index of ischaemic severity (myocardial PCO2 (PmCO2] and myocardial water accumulation during a 2 h anterior descending coronary artery (LAD) occlusion in open chest anaesthetised dogs. In seven dogs studied without mannitol intervention, LAD ligation resulted in an initial fall in regional blood flow to 25% of control flow followed by no significant change thereafter. Myocardial PCO2 distal to the ligation rose to a peak of 34.0 +/- 4.4 kPa (256 +/- 89) (mean +/- SEM). At the completion of the 2 h ischaemia period, myocardial water content was 8.4% greater in ischaemic than non-ischaemic tissue (3.87 +/- 0.11 and 3.57 +/- 0.03 g X g-1 dry weight respectively). In seven additional dogs, mannitol infusion begun 12 min following occlusion resulted in an increase in plasma osmolarity from 304 +/- 5 to 346 +/- 8 mosmol X litre-1, but failed to influence regional flow, PmCO2, or water accumulation in the ischaemic tissue. The inability of mannitol to favourably influence the severity of myocardial ischaemia during prolonged coronary occlusion may be due to its inability to prevent myocardial cell swelling in this model.
Assuntos
Doença das Coronárias/fisiopatologia , Manitol/farmacologia , Animais , Água Corporal/metabolismo , Dióxido de Carbono/metabolismo , Circulação Coronária/efeitos dos fármacos , Doença das Coronárias/metabolismo , Cães , Feminino , Coração/efeitos dos fármacos , Hemodinâmica , Soluções Hipertônicas , Infusões Parenterais , Masculino , Miocárdio/metabolismo , Pressão ParcialRESUMO
OBJECTIVE: The present study was designed to identify the predictors of cross-sectional area narrowing by neointima (%CSAN-N) after balloon angioplasty (BA) in the cholesterol fed rabbit model. METHODS: Angiographic, histomorphometric, and immunohistochemical data were analyzed from 91 femoral arteries of New Zealand white rabbits. Focal atherosclerosis was induced by air desiccation of the endothelium followed by a 2% cholesterol diet for 28 days. The rabbits received heparin (150 U/kg) at the time of BA (2.5 mm; three, 60-second, 10-atm inflations). Arteries were perfusion-fixed and excised 7 (n = 16), 14 (n = 11), 21 (n = 9), or 28 (n = 20) days after BA. Non-angioplastied arteries were de-endothelialized (cholesterol-fed [n = 12] or normal diet [n = 8]), non-injured but cholesterol-fed (n = 7), or normal (n = 8). RESULTS: Univariate regression across all groups showed that the absolute area of the lumen by histomorphometry (LA) correlated significantly with the area bounded by the external elastic lamina (EEL) (vessel size), but no correlation was found with the absolute area of neointima or media, the percentage disruption of the internal elastic lamina (IEL), or the percentage of neointima and media occupied by foam cells. However, %CSAN-N correlated significantly with the area bounded by the EEL, significantly with the absolute neointimal area, and negatively with the absolute LA (p < 0.0001). Significant correlations were also found between %CSAN-N and the % IEL disrupted, the area of neointima and media occupied by RAM-11 + foam cells, and the loss of alpha-actin positivity in the media (p < 0.0001). CONCLUSIONS: These studies show that neointimal formation contributes significantly to luminal narrowing 1 month after angioplasty in this model, that the degree of vascular injury and the extent of foam cell accumulation in the neointima and media are significant independent predictors of neointimal formation, and that the area of the neointima, and the percent narrowing by neointima, are important predictors of remodeling itself (EEL area). These predictors were not identifiable when the analysis was focused on the determinants of absolute luminal area alone.
Assuntos
Angioplastia com Balão , Arteriosclerose/terapia , Artéria Femoral/lesões , Análise de Variância , Angioplastia com Balão/efeitos adversos , Animais , Arteriosclerose/etiologia , Arteriosclerose/patologia , Contagem de Células , Colesterol na Dieta/efeitos adversos , Artéria Femoral/patologia , Células Espumosas/patologia , Período Pós-Operatório , Prognóstico , Coelhos , Recidiva , Análise de Regressão , Túnica Íntima/patologiaRESUMO
This study was conducted in human subjects and in baboons to assess elements of the beta-adrenergic receptor complex in vivo and in vitro following cardiac transplantation. In human subjects, the concentration at which administered isoproterenol increased heart rate by 25 beats per min was within the normal range (mean, 3.2 +/- 0.4 micrograms). Myocardial biopsies and lymphocytes were obtained from 14 transplant recipients undergoing routine right heart catheterization. The stimulatory guanine nucleotide regulatory protein, Gs, was significantly greater in the lymphocyte than in right ventricular myocardium (5.8 +/- 1.7 vs. 2.0 +/- 0.5 relative to standard rat heart membrane preparation, P less than 0.05). In contrast, Gi was significantly greater in the myocardium than in the lymphocyte (4.2 +/- 1.3 vs. 1.1 +/- 0.3, P less than 0.025). There was no correlation between lymphocyte and cardiac G protein determinations. In the autotransplanted baboon heart, beta-receptors were increased (73 +/- 4 vs. 36 +/- 10 fmol/mg, P less than 0.05). Gs was not significantly different in denervated myocardial tissue vs. control cardiac tissue (1.1 +/- 0.2 vs. 0.8 +/- 0.2, P greater than 0.05). However, the inhibitory G protein, Gi, was significantly greater in transplanted animals (0.4 +/- 0.1 vs. 0.2 +/- 0.04, P less than 0.05). Relative enrichment of a Gi-like protein in the autotransplanted baboon heart was associated with a non-statistically significant trend towards a uniform reduction in basal and Gs-mediated adrenergic effects on adenylate cyclase activity. Despite the lack of biochemical evidence of enhanced beta-adrenergic receptor-mediated adenylate cyclase coupling, denervation in the autotransplanted baboon was associated with in vitro evidence of chronotropic and inotropic supersensitivity to isoproterenol. The results call into question the notion of adrenergic hypersensitivity in human subjects following cardiac transplantation, indicate the potential role for guanine nucleotide regulatory proteins in mediating responses of the denervated heart, and distinguish between several characteristics of the chronically denervated, transplanted human heart compared with the acutely auto-denervated of the baboon heart.
Assuntos
Proteínas de Ligação ao GTP/análise , Transplante de Coração/fisiologia , Receptores Adrenérgicos beta/análise , Adenilil Ciclases/metabolismo , Adulto , Animais , Humanos , Isoproterenol/farmacologia , Linfócitos/química , Linfócitos/ultraestrutura , Masculino , Pessoa de Meia-Idade , Miocárdio/química , Norepinefrina/sangue , Papio , Ramos Subendocárdicos/efeitos dos fármacos , Transplante AutólogoRESUMO
We studied 57 patients with a recent infarction and an occluded infarct-related artery to test the hypothesis that the amount of 201Tl on delayed planar images correlates with the extent of viable myocardium after acute myocardial infarction. There was a significant (p < 0.001) correlation between mean 201Tl activity in the infarct zone and regional wall motion score in that zone both at baseline (r = -0.60, n = 57) and 1 mo after attempted angioplasty (r = -0.67, n = 48), with better function being associated with greater 201Tl uptake in the delayed images. There was no correlation between the number of segments showing redistribution and the wall motion score. We conclude that in patients with recent myocardial infarction and an occluded infarct-related artery, the average 201Tl activity within the infarct zone on delayed planar imaging correlates well with the extent of viable myocardium in that zone. The presence or absence of redistribution does not influence these results.
Assuntos
Arteriopatias Oclusivas/patologia , Vasos Coronários , Coração/diagnóstico por imagem , Infarto/patologia , Infarto do Miocárdio/diagnóstico por imagem , Miocárdio/patologia , Radioisótopos de Tálio , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , CintilografiaRESUMO
We hypothesized that viable myocardium can be identified in patients with poor left ventricular (LV) systolic function caused by recent or prior infarction using myocardial contrast echocardiography. Accordingly, 39 patients with reduced LV ejection fraction (range 0.10 to 0.40) and recent (n = 30) or remote (n = 9) myocardial infarction were studied. Echocardiography was performed at baseline and at 1 month to assess regional function (1 = normal, 5 = dyskinesia) in 12 segments/patient; the segments were also scored for contrast effect (1 = homogenous, 0.5 = partial, 0 = none) during contrast echocardiography performed in the cardiac catheterization laboratory. Four patients had unsuccessful angioplasty of occluded arteries and were treated medically, 9 were treated medically because of noncritical coronary stenoses (< 80%), and 26 underwent revascularization (16 angioplasty and 10 bypass operation). Twelve segments could not be visualized (2 each in 6 patients), and 30 segments continued to be subserved by totally occluded arteries because of unsuccessful angioplasty in 4 patients. Of the remaining 426 segments, 186 (44%) demonstrated baseline wall motion scores of > or = 3. The best correlate of 1-month wall motion score in these segments was the contrast score (p = -0.62), with better 1-month function noted in segments with more contrast. The overall perfusion status of LV myocardium also correlated (p = -0.59) with global LV systolic function at 1 month. We conclude that myocardial contrast echocardiography can be used during cardiac catheterization to define myocardial segments that are viable in patients with poor LV systolic function caused by recent or remote myocardial infarction.
Assuntos
Ecocardiografia , Contração Miocárdica , Infarto do Miocárdio/diagnóstico por imagem , Disfunção Ventricular Esquerda/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Análise de Regressão , Volume Sistólico , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
Early reperfusion (4 to 6 hours) after acute myocardial infarction reduces mortality and reduces the incidence of late potentials on a signal-averaged electrocardiogram (SAECG). Recent reports suggest that reperfusion accomplished after > 6 hours also may reduce mortality. The effect of such later reperfusion on the SAECG is not known. We hypothesized that reperfusion by angioplasty accomplished > 24 hours after onset of infarction would reduce late potentials and improve the parameters on the SAECG. Forty-one patients with a totally occluded infarct-related artery 12 +/- 8 days after infarction underwent attempted angioplasty. SAECG, echocardiography and thallium-201 imaging were performed before and 1 month after attempted angioplasty. Angioplasty resulted in successful reperfusion in 32 patients and was unsuccessful in 9. No change in the incidence of late potentials occurred after successful reperfusion (13 of 32 patients before and 13 of 32 patients 1 month later) or after unsuccessful reperfusion (6 of 9 patients before and 5 of 9 patients 1 month later). Among patients with successful reperfusion, no significant change occurred in the QRS duration or the terminal signal duration < 40 microV. The terminal root-mean-square voltage in microvolts improved significantly at 1 month (31 +/- 25 before to 38 +/- 29 after, p = 0.004). Twenty-two of 32 patients with successful reperfusion had improved wall motion in the infarct zone at 1 month. Despite an improvement in function in these patients, no change in the incidence of late potentials occurred by 1 month.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Angioplastia Coronária com Balão , Eletrocardiografia , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Potenciais de Ação/fisiologia , Angioplastia Coronária com Balão/métodos , Circulação Coronária/fisiologia , Vasos Coronários/patologia , Ecocardiografia , Coração/fisiopatologia , Humanos , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Infarto do Miocárdio/patologia , Volume Sistólico/fisiologia , Radioisótopos de Tálio , Fatores de Tempo , Grau de Desobstrução VascularRESUMO
Myocardial contrast echocardiography, unlike coronary angiography, can define collateral perfusion. This study shows that collateral blood flow can preserve myocardial function beyond a chronically occluded coronary artery.
Assuntos
Circulação Coronária/fisiologia , Doença das Coronárias/diagnóstico por imagem , Ecocardiografia , Idoso , Cateterismo Cardíaco , Circulação Colateral/fisiologia , Angiografia Coronária , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Masculino , Infarto do Miocárdio/fisiopatologiaRESUMO
In 108 consecutive patients without abrupt vessel closure referred for repeat coronary angiography within 30 days of successful coronary intervention, 28 (26%) were found with restenosis at the treated site. None of the 27 patients who underwent stenting were found to have early restenosis; balloon angioplasty without stenting was the only independent predictor of early restenosis in patients with recurrent symptoms within 30 days of intervention.
Assuntos
Angina Pectoris/diagnóstico por imagem , Angioplastia Coronária com Balão , Cateterismo Cardíaco , Angiografia Coronária , Doença das Coronárias/terapia , Stents , Adulto , Idoso , Angioplastia Coronária com Balão/instrumentação , Doença das Coronárias/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , RecidivaRESUMO
To test the hypothesis that left ventricular (LV) performance in aortic regurgitation (AR) can be more completely characterized by measurement of LV volumes in addition to ejection fraction (EF), 27 asymptomatic patients (Group 1), and 22 symptomatic patients (Group 2), and 10 control subjects were studied at rest and during upright bicycle exercise using the first-pass technique and a multicrystal scintillation camera. LV end-diastolic volume was measured by the area-length method. In the control group end-diastolic volume increased 14%, end-systolic volume decreased 22%, and EF increased 22% with exercise. In contrast, in Group 1 patients with AR, end-diastolic volume was elevated at rest and during exercise. The 18% decrease in end-diastolic volume during exercise was significantly different from the control response (p less than 0.01). End-systolic volume was also elevated at rest and during exercise, but the 30% decrease during exercise was a response not significantly different from the control. Although mean EF increased 15% in these patients, EF at peak exercise was significantly lower than that in the controls. In Group 2 patients with AR, resting EF was reduced, the EF response to exercise was abnormal, and end-diastolic and end-systolic volume responses to exercise were significantly different from those in Group 1: end-diastolic volume did not change and end-systolic volume increased. In contrast to the fairly uniform volume responses among all Group 1 patients, there were 2 subgroups based on volume changes within Group 2: 7 of 22 had a decrease in end-diastolic volume and end-systolic volume during exercise and 8 of 22 showed an increase in end-diastolic and end-systolic volume during exercise. In conclusion, LV volumes at rest and exercise give more information about LV functional reserve in symptomatic patients with AR than do EF responses alone, and may be useful in separating symptomatic patients who show a normal end-systolic volume response to exercise from those in whom worsening failure develops during exercise.
Assuntos
Insuficiência da Valva Aórtica/fisiopatologia , Débito Cardíaco , Esforço Físico , Volume Sistólico , Insuficiência da Valva Aórtica/diagnóstico por imagem , Humanos , Cintilografia , DescansoRESUMO
A new single chambered percutaneous intraaortic balloon has been constructed around a central guidewire. The balloon can be wrapped around the guidewire, enabling its insertion into the femoral artery through a 12F sheath inserted with the conventional Seldinger technique. Percutaneous intraaortic balloon insertion has been performed in 27 patients (mean age 58 years) for a variety of medical and surgical indications. Percutaneous balloons could not be advanced into the aorta in two patients (7.4 percent) with severe bilateral aortoiliac occlusive disease. In all 25 patients undergoing intraaortic balloon pumping satisfactory circulatory support was achieved, and 21 (84 percent) of the patients survived to be discharged from the hospital. The mean duration of intraaortic balloon pumping was 3.5 days. Percutaneous intraaortic balloon insertion requires less than 5 minutes and has been successfully performed in the cardiac catheterization laboratory, coronary care unit, operating room and recovery room. After direct balloon removal, external pressure was applied for 30 minutes. No patient experienced hematoma of the groin, aortic dissection, compromised distal pulses or late wound complications. Percutaneous balloon insertion permits the rapid institution of circulatory support and broadens the medical and surgical applications of intraaortic balloon pumping.
Assuntos
Circulação Assistida/métodos , Balão Intra-Aórtico/métodos , Pele , Adulto , Idoso , Circulação Sanguínea , Débito Cardíaco , Feminino , Parada Cardíaca/etiologia , Humanos , Balão Intra-Aórtico/mortalidade , Masculino , Pessoa de Meia-Idade , Choque Séptico/terapiaRESUMO
This review has discussed several nonoperative approaches designed to restore or maintain coronary artery patency in patients with coronary artery disease. Information obtained during the last decade concerning the use of thrombolytic, anticoagulant, and antiplatelet drugs and the development of the technique of PTCA have dramatically changed the clinical management of patients with coronary artery disease. It is likely that the application of these therapies will continue to evolve during the next several years as new pathophysiological insights are obtained and large ongoing or planned clinical trials testing current hypotheses are completed.
Assuntos
Doença das Coronárias/terapia , Angioplastia com Balão , Anticoagulantes/uso terapêutico , Plaquetas/efeitos dos fármacos , Fibrinolíticos/uso terapêutico , Humanos , Estreptoquinase/uso terapêuticoRESUMO
BACKGROUND: This study is the third in a series of investigations on the requisite length of time that patients should be restricted to bed after coronary arteriography or percutaneous transluminal coronary angioplasty using a femoral artery approach. METHODS: A prospective, experimental-control group design with randomization was used initially to compare the incidence of bleeding between patients who remained in bed for 4 hours and patients who remained in bed for 6 hours after sheath removal following percutaneous transluminal coronary angioplasty. RESULTS: Rapid changes in the healthcare environment led to nurses collecting complete data sets for the experimental group only. The experimental group (n = 51) was 73% male and 27% female; mean age was 57 years (SD = 11.4 years). Mean time in bed was 4.1 hours (SD = 0.27 hours). Most patients (98%) did not bleed from the femoral artery access site after remaining in bed for 4 hours following sheath removal. Ninety-two percent of patients required analgesics while in bed. Mean length of stay after the angioplasty was 1.4 days (SD = 0.79 days). Bleeding occurred in one subject and was related to multiple invasive procedures and an activated clotting time of greater than 200 seconds. CONCLUSIONS: Requisite time in bed after percutaneous transluminal coronary angioplasty has been reduced to 4 hours at the University of Virginia Medical Center, the same time required for patients undergoing cardiac catheterization. Discomfort after the procedure remains to be addressed.