RESUMO
Patients with prior invasive fungal infection (IFI) increasingly proceed to allogeneic hematopoietic cell transplantation (HSCT). However, little is known about the impact of prior IFI on survival. Patients with pre-transplant IFI (cases; n=825) were compared with controls (n=10247). A subset analysis assessed outcomes in leukemia patients pre- and post 2001. Cases were older with lower performance status (KPS), more advanced disease, higher likelihood of AML and having received cord blood, reduced intensity conditioning, mold-active fungal prophylaxis and more recently transplanted. Aspergillus spp. and Candida spp. were the most commonly identified pathogens. 68% of patients had primarily pulmonary involvement. Univariate and multivariable analysis demonstrated inferior PFS and overall survival (OS) for cases. At 2 years, cases had higher mortality and shorter PFS with significant increases in non-relapse mortality (NRM) but no difference in relapse. One year probability of post-HSCT IFI was 24% (cases) and 17% (control, P<0.001). The predominant cause of death was underlying malignancy; infectious death was higher in cases (13% vs 9%). In the subset analysis, patients transplanted before 2001 had increased NRM with inferior OS and PFS compared with later cases. Pre-transplant IFI is associated with lower PFS and OS after allogeneic HSCT but significant survivorship was observed. Consequently, pre-transplant IFI should not be a contraindication to allogeneic HSCT in otherwise suitable candidates. Documented pre-transplant IFI is associated with lower PFS and OS after allogeneic HSCT. However, mortality post transplant is more influenced by advanced disease status than previous IFI. Pre-transplant IFI does not appear to be a contraindication to allogeneic HSCT.
Assuntos
Aspergilose , Aspergillus , Candida , Candidíase , Transplante de Células-Tronco de Sangue do Cordão Umbilical , Neoplasias Hematológicas , Sistema de Registros , Adolescente , Adulto , Idoso , Aloenxertos , Aspergilose/etiologia , Aspergilose/mortalidade , Aspergilose/terapia , Candidíase/etiologia , Candidíase/mortalidade , Candidíase/terapia , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Neoplasias Hematológicas/mortalidade , Neoplasias Hematológicas/terapia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Taxa de SobrevidaRESUMO
We compared the effects of single doses of 50 mg atenolol (cardioselective), 40 mg propranolol (nonselective), and placebo on both exercise- and isoproterenol-induced tachycardia in two experiments involving nine normal subjects. Maximal exercise heart rate was reduced from 187 +/- 4(SEM) after placebo to 146 +/- 7 bpm after atenolol and 138 +/- 6 bpm after propranolol, but there were no differences between the drugs. The effects on isoproterenol tachycardia were determined before and after atropine (0.04 mg/kg IV). Isoproterenol sensitivity was determined as the intravenous dose that increased heart rate by 25 bpm (CD25) and this was increased from 1.8 +/- 0.3 micrograms after placebo to 38.9 +/- 8.3 micrograms after propranolol and 8.3 +/- 1.7 micrograms after atenolol. The difference in the effects of the two was significant. After atropine the CD25 was unchanged after placebo (2.3 +/- 0.3 micrograms) and atenolol (7.7 +/- 1.3 micrograms); it was reduced after propranolol (24.8 +/- 5.0 micrograms), but remained different from atenolol. This change with propranolol sensitivity was calculated as the apparent Ka, this was unchanged by atropine (11.7 +/- 2.1 and 10.1 +/- 2.5 ml/ng). These data are consistent with the hypothesis that exercise-induced tachycardia results largely from beta 1-receptor activation that is blocked by both cardioselective and nonselective drugs, whereas isoproterenol activates both beta 1- and beta 2-receptors so that after cardioselective blockade there remains a beta 2-component that can be blocked with a nonselective drug. While there appear to be beta 2-receptors in the human heart, their physiologic or pathologic roles remain to be defined.
Assuntos
Atenolol/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Propanolaminas/farmacologia , Propranolol/farmacologia , Receptores Adrenérgicos beta/efeitos dos fármacos , Receptores Adrenérgicos/efeitos dos fármacos , Adulto , Atenolol/sangue , Método Duplo-Cego , Eletrocardiografia , Humanos , Isoproterenol/antagonistas & inibidores , Masculino , Esforço Físico , Propranolol/sangue , Distribuição AleatóriaRESUMO
The effects of acute alpha 1-adrenoceptor blockade with prazosin, beta 1-adrenoceptor blockade with atenolol, and nonselective beta-adrenoceptor blockade with propranolol were compared in a placebo-controlled crossover study. The study involved measurement of the hemodynamic and metabolic responses to exercise after heavy exercise in order to induce skeletal muscle glycogen depletion and thus enhance the dependence on hepatic glucose output and circulating free fatty acids. Catecholamine responses to exercise were enhanced by glycogen depletion and by both beta-blocking drugs. Catecholamine levels were highest with propranolol; as a consequence, at high work loads, propranolol failed to produce a significant reduction in systolic blood pressure and elevated diastolic blood pressure. At high work loads, atenolol reduced systolic blood pressure but did not change diastolic blood pressure. Both beta blockers reduced free fatty acid levels, but only propranolol accelerated the fall of plasma glucose levels during "glycogen-depleted" exercise. In contrast, during exercise prazosin reduced systolic and diastolic blood pressures, and elevated heart rate and plasma catecholamines, particularly noradrenaline. Concomitantly, prazosin raised free fatty acid and lactate levels, and increased the plasma glucose level at a time when placebo therapy resulted in a steady fall in glucose levels. The results indicate important differences in the hemodynamic effects of cardioselective versus nonselective beta-blockade during long-term (or glycogen-depleted) exercise. The importance of beta 2-mediated hepatic glycogenolysis in man is confirmed. Acute alpha 1-blockade with prazosin induces reflex elevation of catecholamine levels. There is no indication of an important role for an alpha 1-mediated mechanism in hepatic glucose production in man.
Assuntos
Atenolol/farmacologia , Hemodinâmica/efeitos dos fármacos , Esforço Físico , Prazosina/farmacologia , Propranolol/farmacologia , Quinazolinas/farmacologia , Adulto , Glicemia , Catecolaminas/sangue , Ácidos Graxos não Esterificados/sangue , Humanos , Lactatos/sangue , MasculinoRESUMO
The effects of atenolol (50 mg) and propranolol (40 mg) on exercise- and isoproterenol-induced heart rate increments were studied in 9 male volunteers. Propranolol reduced maximal heart rate from 187 +/- 4 to 146 +/- 7 beats/min and atenolol reduced it to 138 +/- 6 beats/min. There was no difference between the drugs at any point during exercise. Isoproterenol sensitivity was measured as the dose of isoproterenol required to increase resting heart rate by 25 beats/min (CD-25). Propranolol increased the CD-25 from 1.8 +/- 0.3 micrograms after placebo to 39 +/- 8 micrograms and atenolol increased the CD-25 to 8 +/- 2 micrograms. The increase by propranolol was significantly greater than that of atenolol. Intravenous atropine (0.04 mg/kg) did not alter the isoproterenol CD-25 during placebo or atenolol. The CD-25 with propranolol decreased after atropine (39 +/- 8 versus 25 +/- 5 micrograms) and was due to diminished plasma propranolol concentrations as the drug sensitivity (measured by Ka) was unchanged before (12 +/- 2 ml/ng) and after (10 +/- 3 ml/ng) atropine. These data support the hypothesis that moderate exercise is primarily a beta 1-mediated response and therefore equally antagonized by cardioselective and nonselective blockers, but that isoproterenol stimulates both beta 1 and beta 2 receptors. The greater ability of the nonselective agent to antagonize isoproterenol tachycardia with no significant change after atropine suggests the presence of cardiac beta 2 chronotropic receptors. The physiologic and pathologic importance of these receptors has yet to be determined.
Assuntos
Coração/fisiologia , Receptores Adrenérgicos beta/fisiologia , Adulto , Atenolol/farmacologia , Método Duplo-Cego , Coração/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Isoproterenol/farmacologia , Masculino , Esforço Físico , Propranolol/farmacologia , Distribuição Aleatória , Receptores Adrenérgicos beta/efeitos dos fármacosRESUMO
The interaction of beta 1-selective (cardioselective) and nonselective beta-adrenoceptor blockade with exercise conditioning was investigated in 30 healthy adult persons. A double-blind protocol was used and the effects of atenolol (100 mg/day), propranolol (80 mg twice daily), and placebo were studied by treadmill testing (Bruce protocol) before and after a 2-month supervised program of dynamic exercise. Exercise tolerance was assessed by time and work performed to exhaustion. Subjects who received propranolol, but not those who received atenolol or placebo, showed an acutely impaired exercise tolerance after drug administration but before training (-8 +/- 4%, p less than 0.05). All 3 groups showed significantly improved exercise capacity following training after drug treatment had been discontinued (atenolol, 22 +/- 6% improvement; propranolol, 13 +/- 6%; placebo, 10 +/- 3%). However, when tested while still receiving medication, subjects who received propranolol failed to show significant improvement in exercise capacity. In contrast, patients who received atenolol and placebo improved significantly. The data indicate that enhancement of maximal work capacity by exercise conditioning can occur despite administration of either beta 1-selective or nonselective beta-adrenoceptor antagonists. However, the fatiguing effects of propranolol that were evident when work performance during propranolol therapy was compared with work performance while not receiving propranolol before the training program persists after training and may limit the net improvement in work capacity induced by exercise conditioning compared with the pretraining state.
Assuntos
Atenolol/farmacologia , Resistência Física/efeitos dos fármacos , Propranolol/farmacologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Ensaios Clínicos como Assunto , Método Duplo-Cego , Teste de Esforço , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Lactatos/sangue , Masculino , Pessoa de Meia-Idade , Educação Física e TreinamentoRESUMO
Primary pulmonary hypertension is a rare but difficult-to-manage condition. Adequate clinical trials of agents used in its treatment have not been performed. A variety of drugs have been reported to provide benefit in patients with primary pulmonary hypertension, including beta-adrenoceptor agonists, alpha-adrenoceptor antagonists, and vasodilators such as isosorbide dinitrate, diazoxide, hydralazine, angiotensin converting enzyme inhibitors, prostaglandins and calcium antagonists. Calcium antagonists appear to offer the most promise, although treatment failures have occurred with them as well as with all other drugs used in this condition. In the absence of a specific treatment for primary pulmonary hypertension, several of the agents listed above should be tried before accepting therapeutic failure. Invasive investigation is necessary to adequately monitor the acute response to therapy. Whether combination therapy with 2 or more drugs might improve the response to treatment is an area worthy of further research.
Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão Pulmonar/tratamento farmacológico , Antagonistas Adrenérgicos alfa/uso terapêutico , Antagonistas Adrenérgicos beta/uso terapêutico , Anticoagulantes/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Humanos , Vasodilatadores/uso terapêuticoRESUMO
Renal transplantation in the face of circulating anti-glomerular basement membrane (GBM) antibody can lead to recurrent glomerulonephritis. The severity of the recurrence may be related to the level of antibody present at the time of transplantation. We describe a patient with Goodpasture's Syndrome and moderate circulating anti-GBM antibody activity who received a renal transplant, followed by plasmapheresis and immunosuppression. The graft has functioned well for almost two years associated with a continued reduction in levels of circulating anti-GBM antibody.
Assuntos
Doença Antimembrana Basal Glomerular/terapia , Terapia de Imunossupressão , Transplante de Rim , Plasmaferese , Adulto , Doença Antimembrana Basal Glomerular/imunologia , Anticorpos , Membrana Basal/imunologia , Humanos , Glomérulos Renais/imunologia , Masculino , Transplante HomólogoRESUMO
This study was designed to examine the influence of arteriovenous (A-V) fistulas on cardiac output and left ventricular performance in 13 uremic patients on regular hemodialysis. M-mode echocardiography and systolic time intervals were used to derive indices of left ventricular function, and cardiac output was measured by thermodilution. Measurements were performed before and after acute digital occlusion of the A-V fistulas. Occlusion of a single fistula caused systemic vascular resistance and the systolic diameter of the left ventricle to increase from 9.6 +/- 1 to 13.5 +/- 2 units (p less than 0.001) and from 3.2 +/- .3 to 3.4 +/- .4 (p less than 0.05) respectively. The increase in afterload caused a reduction in cardiac output from 11.0 +/- 1 to 9.6 +/- 1 l/min (p less than 0.001) and probably accounted for the minor, though not significant, "deterioration" in the indices of left ventricular function. Bilateral fistula occlusion in 8 patients exaggerated these changes, and the reduction in fractional shortening from 43 +/- 4 to 37 +/- 4% was significant at the 5% level. In two patients with severe left ventricular failure, fistula occlusion caused a more pronounced deterioration in cardiac performance. These results show that acute A-V fistula occlusion effectively lowers cardiac output and is, therefore, likely to be beneficial in the management of high output failure. However, when intrinsic left ventricular disease is the primary etiological factor in heart failure, fistula occlusion is unlikely to be helpful, and may worsen the hemodynamic derangement.
Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Débito Cardíaco , Hemodinâmica , Diálise Renal/efeitos adversos , Volume Sistólico , Adulto , Braço/irrigação sanguínea , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Rim/irrigação sanguínea , Masculino , Pessoa de Meia-Idade , Resistência VascularRESUMO
Patients may present with a variety of syndromes related to ischaemic heart disease. These include unstable or stable angina pectoris, acute myocardial infarction, and occasionally cardiac failure without prior anginal pain or infarction. For the purposes of this review, it will generally be assumed that the condition has been stabilised, though one important aspect of the rehabilitation process is the recognition of continuing or recurrent problems such as angina pectoris and cardiac decompensation. This should then be followed by appropriate intervention. The key components of post-hospital management of such patients are: (i) support; (ii) education; (iii) assessment; (iv) intervention (if necessary); (v) therapy; and (vi) lifestyle modification.
Assuntos
Isquemia Miocárdica/prevenção & controle , Antagonistas Adrenérgicos beta/uso terapêutico , Consumo de Bebidas Alcoólicas , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Antioxidantes/administração & dosagem , Reestenose Coronária/prevenção & controle , Terapia por Exercício , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Isquemia Miocárdica/psicologia , Isquemia Miocárdica/reabilitação , Cooperação do Paciente , Educação de Pacientes como Assunto , Fitosteróis/administração & dosagem , Medição de Risco , Abandono do Hábito de Fumar , Apoio Social , Terapia Trombolítica , Redução de PesoRESUMO
1. Most of the evidence for chronic non-neurological toxicity from volatile substance abuse is derived from case reports. 2. Factors important in assessing these reports are the marked variations in exposure conditions and in the composition of the products abused. 3. In a young and otherwise healthy population, any chronic organ toxicity arising from VSA has to be gross in order to become clinically apparent. This may partially explain the relatively low incidence of reporting. 4. Toluene and the chlorinated hydrocarbons 1,1,1-trichloroethane and trichloroethylene can cause permanent damage to the kidney, liver, heart and lung, in certain volatile substance abusers.
Assuntos
Solventes/toxicidade , Transtornos Relacionados ao Uso de Substâncias/patologia , Acidose Tubular Renal/induzido quimicamente , Morte Súbita/etiologia , Exposição Ambiental , Glomerulonefrite/induzido quimicamente , Coração/efeitos dos fármacos , Humanos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Concentração Máxima Permitida , Tolueno/toxicidade , Tricloroetanos/toxicidade , Tricloroetileno/toxicidadeRESUMO
During 1976, 24-hour ambulatory electrocardiographic (ECG) monitoring was available to all physicians at this hospital, and 281 patients were investigated by 322 recordings. Cardiac arrhythmias requiring treatment were detected in 100 patients (36%). Some presented after symptoms such as faintness, giddiness, palpitations, collapse, or fits, but ominous arrhythmias were also found in asymptomatic patients. A demand pacemaker was implanted for episodic sinoatrial or atrioventricular conduction disorder in 30, while 70 patients (25%) required antiarrhythmic drug treatment for ventricular or atrial tachyarrhythmias. Facilities for ambulatory 24-hour ECG monitoring are necessary in any large hospital, and precise diagnosis in most of our patients studied could not have been achieved by any other investigation.
Assuntos
Eletrocardiografia , Monitorização Fisiológica , Adolescente , Adulto , Idoso , Assistência Ambulatorial , Arritmias Cardíacas/diagnóstico , Bloqueio Cardíaco/diagnóstico , Hospitais Gerais , Humanos , Londres , Pessoa de Meia-IdadeRESUMO
A 22-year-old woman required emergency mitral valve replacement three weeks post partum because of thrombotic obstruction of her prosthetic mitral valve. Low dose subcutaneous heparin was administered from the 17th week of pregnancy. Though there was a successful fetal outcome, heparin did not prevent thrombosis on the prosthesis and its continuation into the puerperium proved nearly fatal.
Assuntos
Próteses Valvulares Cardíacas , Valva Mitral , Complicações Pós-Operatórias , Transtornos Puerperais/etiologia , Trombose/etiologia , Adulto , Ecocardiografia , Feminino , Heparina/uso terapêutico , Humanos , GravidezRESUMO
Over six months 10 patients, representing 20% of those referred to a neurological department with possible idiopathic epilepsy, were subsequently considered to have cardiac arrhythmias that caused or significantly contributed to their symptoms. In some cases relevant arrhythmias were shown only after prolonged electrocardiographic monitoring. Although several theoretical and practical factors need to be assessed when considering the cardiac basis for cerebral disturbances, unsuspected cardiac arrhythmias may underlie "epilepsy" in many patients.
Assuntos
Arritmias Cardíacas/diagnóstico , Epilepsia/diagnóstico , Adolescente , Adulto , Idoso , Diagnóstico Diferencial , Eletrocardiografia , Feminino , Humanos , Masculino , Fatores de TempoRESUMO
The postulated beta adrenoceptor blocking properties of the new antiarrhythmic drug propafenone were studied by in vivo comparison against placebo and propranolol in the antagonism of both exercise- and isoproterenol-induced tachycardia and by in vitro radioligand binding studies of animal and human left ventricular muscle membrane preparations. Interaction with frog erythrocyte membrane adenylate cyclase was also investigated. In the clinical studies, a double blind crossover comparison of oral propafenone (300 mg), propranolol (40 mg) and placebo indicated significant antagonism of chronotropic response to isoproterenol 2 hr postdose with dose ratios of 4.1 +/- 1.3 (mean +/- S.E.M.) for propafenone and 16.8 +/- 5.1 for propranolol. Chronotropic response to exercise was modestly reduced by propafenone. Analysis of the binding of [125I]iodocyanopindolol to human left ventricular membranes revealed specific beta adrenoceptor competition by propafenone with an EC50 of 111 +/- 13 nM. Propranolol EC50 was 2.4 +/- 0.2 nM in this system. Competitive inhibition of isoproterenol-stimulated frog erythrocyte membrane adenylate cyclase activity was also obtained with propafenone. The ratio of affinities (calculated from the apparent dissociation constant; KD) for propranolol-propafenone was 1:40 for the in vivo study and 1:50 for the in vitro system. Propafenone is a specific antagonist of the human beta adrenoceptor and this action can be demonstrated during in vivo study in human subjects. At clinical dosages it appears likely that it will achieve a modest degree of beta blockade which may contribute to its antiarrhythmic effect.
Assuntos
Adenilil Ciclases/metabolismo , Antiarrítmicos/farmacologia , Propiofenonas/farmacologia , Receptores Adrenérgicos beta/efeitos dos fármacos , Antagonistas Adrenérgicos beta , Adulto , Animais , Método Duplo-Cego , Eletrocardiografia , Ativação Enzimática , Membrana Eritrocítica/enzimologia , Humanos , Masculino , Esforço Físico , Propafenona , Propranolol/uso terapêutico , Ensaio Radioligante , Ranidae , Ratos , Ratos Endogâmicos , Taquicardia/tratamento farmacológicoRESUMO
Echocardiography was used to study the prevalence and severity of left ventricular hypertrophy in patients with established diabetic nephropathy (persistent proteinuria for at least 2 y plus severe retinopathy). Fifteen patients had mild renal impairment (serum creatinine less than 150 mumol l-1), 14 patients had moderate renal impairment (serum creatinine 150-400 mumol l-1), and 20 patients had severe renal impairment (serum creatinine greater than 400 mumol l-1). Thirty-six of the 49 (73%) were on anti-hypertensive treatment, despite which mean blood pressure was 161 +/- 25/89 +/- 9 (+/- SD) mmHg. Left ventricular hypertrophy was demonstrated in 42 of the 49 patients (85%), and increased in severity with increasing renal impairment. Interventricular septal + left ventricular posterior wall thickness was 25 +/- 3 mm in those with mild renal impairment, 28 +/- 6 mm in those with moderate renal impairment and 30 +/- 4 mm in those with severe renal impairment. The most severe left ventricular hypertrophy was seen in the Afro-Caribbean patients. Left ventricular hypertrophy was present even in those with marginally raised blood pressure and was related to age and serum creatinine but not to present blood pressure or duration of proteinuria.
Assuntos
Cardiomegalia/complicações , Nefropatias Diabéticas/complicações , Adulto , Pressão Sanguínea , Cardiomegalia/diagnóstico , Creatinina/sangue , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Ecocardiografia , Feminino , Ventrículos do Coração/anatomia & histologia , Humanos , MasculinoRESUMO
Two patients showed evidence of chronic cardiac toxicity after repeated exposure to 1,1,1-trichloroethane. In both cases there was circumstantial evidence of a deterioration after routine anaesthetic use of the related compound halothane. An adolescent boy who sniffed trichloroethane presented with multiple ventricular arrhythmias during tonsillectomy. Follow up showed mild chronic left ventricular impairment. A 54 year old man had repeated industrial exposure to trichloroethane and deteriorated from mild stable cardiac failure to end stage cardiac failure after halothane anaesthesia for herniorrhaphy. Chronic cardiac toxicity is a previously unreported feature of this type of solvent exposure. Related compounds such as halothane may have a toxic interaction after exposure to trichloroethane.
Assuntos
Coração/efeitos dos fármacos , Hidrocarbonetos Clorados , Solventes , Transtornos Relacionados ao Uso de Substâncias/complicações , Tricloroetanos , Adolescente , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/diagnóstico , Doença Crônica , Ecocardiografia , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/diagnóstico , Humanos , Hidrocarbonetos Clorados/farmacologia , Masculino , Pessoa de Meia-Idade , Solventes/farmacologia , Tricloroetanos/farmacologiaRESUMO
The effect of oral doses of the beta 1-selective adrenoceptor antagonist atenolol (50 mg), the non-selective antagonist propranolol (40 mg) and placebo was investigated during exercise in a crossover comparison in six healthy but untrained subjects. Descriptors of ventilation, respiratory gas exchange, and arterialized blood lactate and glucose were obtained during steady state bicycle ergometric exercise at 20% and 60% of the subjects' previously determined maximal oxygen uptake (VO2 max). At these work intensities, the previously reported increase of respiratory exchange ratio (RER) during non-selective beta-adrenoceptor blockade was found to be trivial (placebo = 0.96 +/- 0.03 s.e. mean; propranolol = 0.97 +/- 0.01; atenolol = 0.97 +/- 0.04; 60% VO2 max, 10 min exercise) and only present during the early minutes of effort. Oxygen uptake and carbon dioxide production did not differ between treatments. Both drugs produced highly significant falls in peak expiratory flow (PEF) rates and tidal volume (VT) which were compensated by an increase in respiratory rate. PEF, 60% VO2 max: placebo = 3.8 +/- 0.3 l/s; propranolol 3.6 +/- 0.3 l/s (P less than 0.03); atenolol 3.1 +/- 0.3 l/s (P less than 0.01). VT, 60% VO2 max: placebo 2.0 +/- 0.1 l; propranolol 1.8 +/- 0.21 (P less than 0.05); atenolol 1.7 +/- 0.1 1 (P less than 0.01). Arterialized lactate was significantly elevated during work at 20% and 60% VO2 max, but rose progressively at the 60% VO2 max load. Ventilation, oxygen uptake and ventilatory equivalent for carbon dioxide also rose progressively at this workload. Ventilatory equivalent for oxygen showed no significant rise.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Lactatos/sangue , Consumo de Oxigênio/efeitos dos fármacos , Esforço Físico , Troca Gasosa Pulmonar/efeitos dos fármacos , Adulto , Atenolol/farmacologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Ácido Láctico , Masculino , Propranolol/farmacologia , Receptores Adrenérgicos beta/efeitos dos fármacosRESUMO
During a five-year period, 26 cases of acute thoracic aortic dissection were studied by M-mode and cross-sectional echocardiography prior to cardiac catheterization and aortography. The diagnosis could be made non-invasively in 20 patients. Important information concerning the extent of the dissection, and the presence or absence of aortic regurgitation or a pericardial effusion could be obtained. Negative examinations were largely confined to cases where the distal thoracic aorta alone was involved. In a further 30 cases admitted to the coronary care unit during this period in which echocardiography was performed to rule out aortic dissection, two false-positive examinations led to aortography which demonstrated aortic dilatation and aortic regurgitation only. In the remaining 28 cases, echocardiographic examination was negative and none of these patients subsequently evidenced aortic dissection. Echocardiography using both M-mode and cross-sectional techniques is a rapid and highly effective method of making an early diagnosis of thoracic aortic dissection. Cross-sectional echocardiography is complementary to the M-mode technique, enhancing diagnostic accuracy by improving structural recognition in a condition where the normal anatomy is often severely distorted.