RESUMO
Zika virus infection is associated with the development of severe neurological disorders in adults and newborns. Although at the moment Zika virus outbreak is not threatening to become again an emergency, infection cases are still being sporadically reported and there is still no effective therapy available. A possible treatment to suppress Zika replication is represented by short interfering RNAs (siRNAs), since they have been successfully used even against Ebola, H5N1 and SARS viruses and clinical trials of siRNA-based drugs are ongoing. In order to speed up the time consuming experimental validation of effective siRNAs, we have performed a comprehensive bioinformatic analysis to design only a few promising siRNAs against Zika virus. Besides siRNA efficacy, we paid attention to broad-spectrum antiviral activity, obtained by analysing all known Zika genomes, and siRNA safety, by excluding siRNAs that could potentially provoke an immune response or interfere with host mRNAs, lncRNAs, circRNAs and RNA binding proteins. In Zika genome we identified several highly conserved regions targetable by only 20 siRNAs. In particular, only a few siRNAs survived highly stringent criteria for siRNA safety. Notably, two of our candidate siRNAs have been successfully used against other flaviviruses like Zika, both in in vitro and in vivo models. Since they were effective against two different flaviviruses, by targeting a highly conserved region, it is reasonable to hypothesize that they could be active also against Zika. Therefore, we encourage researchers to experimentally validate these promising siRNAs.
Assuntos
Antivirais/uso terapêutico , RNA Interferente Pequeno/uso terapêutico , Terapêutica com RNAi , Infecção por Zika virus/terapia , Zika virus/genética , Antivirais/farmacologia , Biologia Computacional , Genoma Viral , Humanos , Terapia de Alvo Molecular , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Segurança , Replicação Viral/efeitos dos fármacos , Zika virus/efeitos dos fármacos , Zika virus/fisiologiaRESUMO
Bile duct ligation in the rat leads to a rapid increase in hepatic and serum alkaline phosphatase activity. Within 12 hr after bile duct ligation, hepatic alkaline phosphatase has increased 7-fold and serum alkaline phosphatase activity 2(1/2)-fold. The elevation in the serum activity is completely due to an increase in an isozyme that appears to originate in the liver. This serum isozyme and liver phosphatase, both partially purified by DEAE-cellulose column chromatography, have identical Michaelis constants, pH optima, and rates of heat denaturation. These isozymes migrate identically when subjected to electrophoresis on polyacrylamide gel, and their migration rates are equally slowed after neuraminidase digestion. The data suggest that the rise in hepatic alkaline phosphatase activity is dependent on de novo protein synthesis. Cycloheximide, in a dose that inhibited incorporation of leucine-(14)C into protein by 68%, inhibited the rise in liver phosphatase by 98% and that in serum by 80%. The rise in liver phosphatase activity could not be accounted for by simple retention of alkaline phosphatase that would normally appear in bile. The rise in liver activity after bile duct ligation was 240 times greater than the amount of phosphatase that normally appears in bile over a similar period of time. Cycloheximide had no effect on the bile duct ligation-induced changes in the serum and liver glutamic pyruvic transaminase.
Assuntos
Fosfatase Alcalina/metabolismo , Ductos Biliares , Fígado/enzimologia , Alanina Transaminase/sangue , Alanina Transaminase/metabolismo , Fosfatase Alcalina/análise , Fosfatase Alcalina/sangue , Animais , Bile/enzimologia , Ductos Biliares/cirurgia , Isótopos de Carbono , Cromatografia DEAE-Celulose , Cicloeximida/farmacologia , Eletroforese , Temperatura Alta , Concentração de Íons de Hidrogênio , Isoenzimas/metabolismo , Leucina/metabolismo , Fígado/metabolismo , Hepatopatias/enzimologia , Masculino , Biossíntese de Proteínas , Ratos , Fatores de TempoRESUMO
OBJECTIVE: The intercycle FSH signal that initiates follicular recruitment and marks the functional onset of the menstrual cycle is of small amplitude and while it commonly occurs on cycle day 3, this often varies. Hence, its identification and measurement in serum (sFSH) requires serial daily samplings. We attempted to determine whether urine measurements of FSH (uFSH) could offer a non-invasive alternative, using a model where the intercycle FSH signal is controlled by timely use of exogenous E2. PATIENTS AND METHODS: Pilot prospective trial in 21 infertile women having received E2, from day 25 of the previous cycle until the 1st Friday after menses. Blood and first void urine samples were collected, starting on the last day of E2 (baseline) for assessing FSH and creatinin. A sonogram was performed for identification of maturing follicles (>12 mm). RESULTS: uFSH and uFSH/Cr showed good correlation with sFSH (R = 0.52 and 0.63, P < 0.0001 and P < 0.0001, respectively). In 15/21 patients who had an intercycle sFSH elevation, this was confirmed by uFSH elevation, both occurring within 2-4 days after stopping E2. In all these women, the sonogram showed evidence of impending ovulation. The amplitude of the uFSH signal was on average 3 times higher than its sFSH counterpart. In 6/21 women, no intercycle FSH elevation was detected and no ovulation occurred. DISCUSSION AND CONCLUSION: Our results show that the intercycle FSH signal can easily be identified and measured in urine. This novel approach permits more precise assessments of ovarian physiology than with blood measurements.
Assuntos
Hormônio Foliculoestimulante/urina , Ciclo Menstrual/urina , Adulto , Creatinina/urina , Estradiol/administração & dosagem , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Hormônio Luteinizante/urina , Ovulação , Fatores de TempoRESUMO
BACKGROUND: Paraoxonase is an HDL-associated enzyme that protects lipoproteins from oxidative modifications. Smoking is a major cardiovascular risk factor that promotes lipid peroxidation. Cigarette smoke has been shown in vitro to inhibit paraoxonase. The present study examined the hypothesis that smoking is associated with modulated serum activities and concentrations of paraoxonase. METHODS AND RESULTS: Coronary artery disease was assessed with the use of coronary arteriography in participants recruited from a hospital cardiology division. Medical and lifestyle data were obtained, and a fasting blood sample was provided. Three smoking categories were established (never, ex-smokers, and current smokers), and serum paraoxonase variables were compared among them. The activities and concentrations of paraoxonase were significantly lower in current than in never smokers. Ex-smokers had values comparable to those of never smokers. Ex-smokers who had recently stopped (<3 months) had activities and concentrations comparable to those of current smokers; values returned to the levels of never smokers within 2 years of cessation of smoking. Smoking status was an independent determinant of paraoxonase activity and concentration in multivariate analysis. Finally, lower paraoxonase was associated with more severe coronary disease and a reduced capacity to protect LDL from oxidation. CONCLUSIONS: Smoking is independently associated with significant decreases in serum paraoxonase activities and concentrations, which normalize within a relatively short time of cessation. Lower serum paraoxonase is linked to more severe coronary artery disease and a lower antioxidant capacity. The data are consistent with the hypothesis that smoking modifies serum paraoxonase such that there is an increased risk of coronary artery disease due to a diminished capacity to protect lipoproteins from oxidative stress.
Assuntos
Doença das Coronárias/sangue , Esterases/sangue , Fumar/efeitos adversos , Idoso , Arildialquilfosfatase , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Lipoproteínas LDL/metabolismo , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Oxirredução , Análise de Regressão , Índice de Gravidade de Doença , Abandono do Hábito de FumarRESUMO
The aim of this investigation was to determine the difference in accuracy between two frequently published noninvasive indicators of severity of coronary artery disease (exercise-induced ST segment depression and heart rate-adjusted ST depression [ST/HR index]). The study was designed as a survey of consecutive patients undergoing exercise electrocardiography and coronary angiography. There were a total of 2,270 patients without prior myocardial infarction or cardiac valvular disease referred for angiography from eight institutions in three countries; 401 of these patients had triple-vessel or left main coronary artery disease. The sensitivities of ST depression and ST/HR index in detecting triple-vessel or left main coronary artery disease were, respectively, 75% and 78% (p = 0.08) at cut point values where their specificities were equal (64%). This small increase in the accuracy of the ST/HR index was evident only at peak exercise heart rates below the median value of 132 beats/min, where the sensitivities of ST depression and ST/HR index were 73% and 76% (p = 0.03), respectively, at cut point values corresponding to a specificity of 60%. These results were consistent at all eight participating institutions. The increase in accuracy achieved by dividing exercise-induced ST depression by heart rate is small and confined exclusively to a low exercise heart rate. This lack of superiority cannot be generalized to all methods of heart rate adjustment.
Assuntos
Doença das Coronárias/diagnóstico , Eletrocardiografia , Teste de Esforço , Frequência Cardíaca/fisiologia , Viés , Angiografia Coronária , Doença das Coronárias/epidemiologia , Doença das Coronárias/mortalidade , Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Europa (Continente)/epidemiologia , Teste de Esforço/métodos , Teste de Esforço/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Encaminhamento e Consulta , Estados Unidos/epidemiologiaRESUMO
This study tested the hypothesis that promoter polymorphism T(-107)C of the human paraoxonase gene (PON1) is associated with risk of coronary disease. Participants (n=897) were recruited from a cardiology department. All underwent coronary arteriography and were defined as coronary artery disease positive (n=699) or negative (n=198). No association of the promoter genotypes with coronary disease was observed in the overall population, but the high expressor genotype (-107CC) was associated with decreased risk of disease in patients aged 60 years or under in univariate and multivariate analysis independently of established risk factors. A significant deficiency in paraoxonase relative to cholesterol was apparent in patients, even when they were matched with controls for total and low-density lipoprotein cholesterol levels. The -107 polymorphism was not associated with risk in older patients (61 years or over). Age was negatively associated with serum concentrations and activities of paraoxonase; serum paraoxonase was significantly higher in those aged under 61 years than in those aged 61 or over. Age was an independent predictor of paraoxonase concentrations. The results indicate that in this population of patients the promoter polymorphism T(-107)C of the PON1 gene is an independent risk factor for coronary disease in those 60 years or younger. The data are consistent with the hypothesis that lower expression of this anti-oxidant enzyme increases risk of coronary disease. Ageing has also been identified as an independent determinant of serum paraoxonase levels. Ageing is correlated with reduced serum paraoxonase levels, which may compromise the protective influence of enzyme. The results are consistent with the contention that the protective, anti-oxidant capacity of high density lipoproteins is at least in part genetically determined.
Assuntos
Doença das Coronárias/genética , Esterases/deficiência , Esterases/genética , Predisposição Genética para Doença/genética , Polimorfismo Genético/genética , Regiões Promotoras Genéticas/genética , Idoso , Envelhecimento/fisiologia , Arildialquilfosfatase , Colesterol/sangue , HDL-Colesterol/sangue , Doença das Coronárias/sangue , Esterases/sangue , Esterases/metabolismo , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangueRESUMO
Patients with diabetes have a higher risk of atherothrombotic disease. These patients have up to 4-fold more coronary artery diseases compared with patients without diabetes. Aspirin is one of the most prescribed treatments in the prevention of cardiovascular diseases. This article focuses on the effect of aspirin in primary prevention with a summary of interventional studies including diabetic patients. The guidelines from different speciality societies, notably the American Diabetes Association, are positive. However, the results of these studies are not conclusive. Cautions recommendations are proposed.
Assuntos
Aspirina/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Humanos , Prevenção PrimáriaRESUMO
The results over a mean period of 2 years of successful percutaneous transluminal coronary angioplasty (PTCA) in 100 consecutive patients with chronic total coronary occlusion were compared with those in 100 consecutive patients whose PTCA was unsuccessful. The groups were comparable in terms of gender, age and arteries attempted. A control angiography in the group with successful PTCA was performed in 62 patients and showed a restenosis in 28 (45%). Repeat PTCA was performed in 21 versus 1 patient with failed PTCA (p less than 0.0001). At follow-up, in the group with successful PTCA, there were 57 symptom-free patients versus 26 patients in the group with failed PTCA (p less than 0.0001). Coronary artery bypass surgery was performed in 7 versus 37 patients (p less than 0.0001), and there were 5 versus 3 deaths (difference not significant), respectively. In the group with successful PTCA, 27 of 82 patients (33%) had positive stress test results, compared with 49 of 85 patients (58%) in the group with unsuccessful PTCA (p less than 0.001). The double product (beats/min x mm Hg/100) in patients with successful PTCA improved from 247 +/- 57 before PTCA to 277 +/- 61 (p less than 0.001) at follow-up, whereas it did not significantly change in patients with failed PTCA. The work load (W) in patients with successful PTCA improved from 95 +/- 34 before PTCA to 124 +/- 40 at follow-up (p less than 0.001). In patients with failed PTCA, work load improved less significantly, from 98 +/- 37 before PTCA to 108 +/- 34 at follow-up (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Angioplastia Coronária com Balão , Arteriopatias Oclusivas/terapia , Doença das Coronárias/terapia , Arteriopatias Oclusivas/epidemiologia , Doença das Coronárias/epidemiologia , Teste de Esforço , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Fatores de TempoRESUMO
To evaluate interventricular septal motion and left ventricular function after coronary bypass graft surgery, 40 patients were studied early postoperatively and serially for up to 16 months with echocardiography and radionuclide angiography. Early after operation mean left septal excursion decreased significantly from 4.6 +/- 0.4 (standard error) to 0.8 +/- 0.6 mm (P less than 0.001), and left septal motion was abnormal in 23 of the 40 patients. Mean right septal excursion reversed from 2.1 +/- 0.5 to -2.1 +/- 0.5 mm early after operation in the 22 patients in whom these measurements could be made, and 15 patients showed paradoxical right septal excursion. At a mean of 4 months after operation, only 7 of 35 patients followed up had abnormal left septal motion, and mean left septal excursion had returned toward normal (3.6 +/- 0.7 mm); mean right septal excursion remained reversed (--1.1 +/- 0.7 mm), and 6 of the 14 patients followed up had paradoxical motion. In the 22 patients whose wall thickness could be measured, mean septal thickening during systole decreased significantly from 35 +/- 4 to 21 +/- 3 percent early after operation (P less than 0.01). During late follow-up septal thickening returned toward normal (32 +/- 4 percent). Mean normalized posterior wall velocity increased significantly after operation from 0.76 +/- 0.03 to 1.01 +/- 0.05 sec-1 (P less than 0.001), but posterior wall thickening remained unchanged. Left ventricular end-diastolic dimension and the radionuclide-determined left ventricular ejection fraction were unchanged postoperatively. It is concluded that (1) echocardiographically detected abnormal septal movement is frequent early after coronary bypass graft operation; (2) both decreased myocardial contraction in the septum and increased anterior movement of the whole heart contribute to this abnormality; (3) the abnormalities in septal movement decrease during late follow-up in many patients but persist in some patients; and (4) posterior wall function tends to increase early after operation and therefore overall left ventricular function remains normal.
Assuntos
Angiografia Coronária , Ponte de Artéria Coronária , Ecocardiografia , Septos Cardíacos/fisiopatologia , Ventrículos do Coração/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Cintilografia , Adulto , Idoso , Débito Cardíaco , Cardiomegalia/fisiopatologia , Doença das Coronárias/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Derrame Pericárdico/diagnósticoRESUMO
The diastolic thickness of the septum and posterior left ventricular wall were measured with M mode echocardiography in 68 patients 2 or more months after a single transmural myocardial infarction. In 42 patients with inferior wall infarction, the septal thickness of 12.4 +/- 0.6 mm (mean +/- standard error of the mean) was larger than the mean measurement in 26 patients with anterior wall infarction (9.6 +/- 0.6 mm, P less than 0.01). Twenty-five of these 42 patients (59 percent) had increased septal thickness (greater than 11 mm), including 12 (48 percent) who had hypertension and 11 (26 percent) who had decreased posterior wall thickness. The ratio of septal to posterior wall thickness was greater in the patients with inferior infarction than in those with anterior infarction (1.36 +/- 0.06 versus 0.89 +/- 0.06, P less than 0.001). This ratio exceeded 1.3 in 22 patients with an inferior infarction (52 percent) but was increased in only 1 patient with an anterior infarction. Hypertension did not predict the presence or absence of an abnormal ratio. Increased septal thickness on echocardiography may occur after interior infarction and result in an abnormal septal to posterior wall thickness ratio that meets current echocardiographic criteria for asymmetric septal hypertrophy.
Assuntos
Cardiomegalia/etiologia , Septos Cardíacos , Infarto do Miocárdio/complicações , Adulto , Idoso , Cardiomegalia/diagnóstico , Ecocardiografia , Eletrocardiografia , Feminino , Ventrículos do Coração , Humanos , Hipertensão/complicações , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnósticoRESUMO
To assess the usefulness of myocardial imaging with technetium-99m-stannous pyrophosphate for detecting acute myocardial necrosis in patients undergoind cardiac surgery, 66 such patients were stldied. Tc-99m (Sn)-pyrophosphate scans were obtained in all patients 3 to 6 days postoperatively and in 45 preoperatively. Electrocardiograms and serum samples for measuring myocardial isoenzyme of creatine kinase (MB CK) levels were obtained before and serially after cardiac surgery. Seven of the 46 patients undergoing myocardial revascularization had a definite new myocardial infarction as indicated by electrocardiogram and MB CK isoenzyme concentrations, and postoperative pyrophosphate scans were abnormal in all but one. In addition, six of the eight patients with possible myocardial infarction (elevated MB CK levels and persistent ST-T wave depressions) had an abnormal scan postoperatively. Seven of the 20 patients undergoing aortic or mitral valve replacement, or both, had a possible postoperative myocardial infarction by electrocardiogram and MB CK criteria and the myocardial scan was positive in two. All the patients with a normal electrocardiogram and normal MB CK levels had a normal pyrophosphate scan. Preoperative scans were obtained in 22 patients wit; valvular heart disease and were positive in two with a heavy calcified mitral valve on fluoroscopy and in one with a calcified aortic valve. After valve replacement, the pyrophosphate scan became normal in two patients and remained abnormal in the third patient with electrocardiograms and MB CK levels suggesting acute myocardial infarction. We conclude that the Tc-99m (Sn)-pyrophosphate scan is useful for analyzing the occurrence of acute myocardial infarction in patients undergoing cardiac surgery and that, in conjunction with the electrocardiogram, it permits confirmation or exclusion of that diagnosis. Furthermore, false positive pyrophosphate scans may occur in patients with heavy valve calcifications.
Assuntos
Doença das Coronárias/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Infarto do Miocárdio/diagnóstico , Cintilografia , Adulto , Idoso , Valva Aórtica , Ponte de Artéria Coronária , Creatina Quinase/sangue , Reações Falso-Positivas , Feminino , Próteses Valvulares Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral , Complicações Pós-Operatórias/diagnóstico , Tecnécio , Polifosfatos de EstanhoRESUMO
The ventricular volume and function changes induced by the addition of 12 cm H2O of positive end-expiratory pressure (PEEP) during mechanical ventilation were studied in 11 patients with the adult respiratory distress syndrome. Cardiac output was measured by thermodilution and ventricular ejection fraction by the multiple gated equilibrated cardiac blood pool scintigraphy. Right and left end-diastolic volumes were then calculated by dividing stroke volume by ejection fraction. The PEEP caused a 14 percent decrease of the cardiac output secondary to a decrease in stroke volume. On the basis of the relationship between stroke volume and ventricular end-diastolic volume, we conclude that reduction in preload was the major component of the decrease in cardiac output. After removal of PEEP, we observed a rebound phenomenon characterized by higher values for stroke volume and cardiac output than before the application of PEEP.
Assuntos
Coração/fisiopatologia , Respiração com Pressão Positiva/efeitos adversos , Síndrome do Desconforto Respiratório/fisiopatologia , Adulto , Dióxido de Carbono/sangue , Débito Cardíaco , Volume Cardíaco , Feminino , Coração/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Oxigênio/sangue , Cintilografia , Síndrome do Desconforto Respiratório/terapia , Volume Sistólico , TermodiluiçãoRESUMO
In 38 patients undergoing elective coronary arterial bypass graft surgery, the radiographic dimension of the left side of the heart was determined and echocardiographic studies were performed before and after surgery. On the plain chest x-ray film one week after surgery, all patients showed an increase in the size of the left side of the heart, which usually was not accompanied by an increase in the echocardiographic left ventricular end-diastolic dimension; however, in 25 patients, pericardial fluid was detected soon after surgery, which would explain the enlarged cardiac silhouettes. Several months after surgery, the radiographic size of the heart returned to the preoperative value in most patients, and pericardial fluid was no longer demonstrated on the echocardiogram. Thus, pericardial fluid frequently is found in the first week following coronary arterial bypass graft surgery and may give the impression of increased cardiac size on plain chest x-ray films; however, echocardiographic studies provide a more accurate estimate of left ventricular size and reveal the presence of pericardial effusion.
Assuntos
Ponte de Artéria Coronária , Ecocardiografia , Coração/diagnóstico por imagem , Adulto , Idoso , Eletrocardiografia , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/diagnóstico por imagem , Derrame Pericárdico/etiologia , RadiografiaRESUMO
It has been suggested that unstable angina at rest, like acute myocardial infarction, might be associated with a thrombotic process. In order to study the hypothesis that myocardial ischemia during exercise could also be associated with an activation of blood coagulation and/or fibrinolysis, we investigated the presence of plasma markers of a prethrombotic or thrombotic state (thrombin-antithrombin III complexes TAT, prothrombin fragment F1 + 2, and D-dimers DD) in 100 consecutive patients with confirmed or suspected coronary artery disease during ergometric test with myocardial thallium-201 scintigraphy. Symptoms and scintigrams allowed to define three groups of patients: those showing no ischemia (n = 79) and those with symptomatic (n = 8) or silent myocardial ischemia (n = 13). Before exercise, DD and TAT levels were not significantly different among the three groups. On the other hand, the F1 + 2 levels were slightly albeit significantly higher in the patients without ischemia than in the patients with symptomatic or silent ischemia. After exercise, no significant difference was found between the three groups. Exercise induced a significant and parallel increase in both the TAT and the F1 + 2 levels (but not of the DD levels) in the three groups. Thus, our study does not support the hypothesis that myocardial ischemia, silent or symptomatic, is associated with an activation of plasma coagulation and fibrinolysis that can be distinguished from the exercise-induced thrombin generation.
Assuntos
Coagulação Sanguínea/fisiologia , Doença das Coronárias/sangue , Fibrinólise/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antifibrinolíticos/sangue , Antitrombina III/metabolismo , Biomarcadores/sangue , Teste de Esforço , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/metabolismo , Peptídeo Hidrolases/metabolismo , Estudos Prospectivos , Protrombina/metabolismoRESUMO
We recently showed that Isradipine, a calcium antagonist from the dihydropyridine group, reduces ischemia and improves ventricular function at rest and during exercise, 2 hours after a single oral dose, in patients with chronic stable angina. In the present study, we evaluated the effects of long acting slow release oral (SRO) Isradipine (5 mg) compared to a placebo in 30 coronary patients with stable chronic angina, randomized in a double blind-fashion. The following parameters were obtained at rest and during submaximal exercise: left and right ventricular (LV, RV) ejection fractions (EF; %) and peak filling rate (PFR; EDV/s), assessed by gated radionuclide angiography, clinical symptoms, electrocardiograms (ECG, ST segment depression; mm), systolic and diastolic blood pressure (SBP and DBP; mm Hg). Patients were then given two oral doses of either Isradipine or placebo (one a day). The same parameters were reassessed, at rest and during n equivalent exercise, 48 hours later (24 hours after the last administration of the drug). The results after Isradipine (n = 14) showed, at rest, a significant increase in LVEF and Pfr (51 +/- 9 to 54 +/- 8 and 1.97 +/- 0.44 to 2.36 +/- 0.71, respectively) and a decrease in DBP (93 +/- 11 to 87 +/- 13); and during exercise, a significant increase in LVEF (51 +/- 11 tot 55 +/- 13) and a decrease in ST segment depression (2.3 +/- 1.9 tot 1.9 +/- 1.6). No significant change was observed after placebo in the other 16 patients. We conclude that even 24 hours after an oral administration, Isradipine SRO maintains its beneficial effects both, at rest on LV systolic and diastolic function and pressure, and during exercise on ECG signs of ischemia with improvement in LV ejection fraction.
Assuntos
Angina Pectoris/tratamento farmacológico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Coração/fisiopatologia , Isradipino/uso terapêutico , Função Ventricular , Adulto , Idoso , Angina Pectoris/diagnóstico por imagem , Angina Pectoris/fisiopatologia , Método Duplo-Cego , Teste de Esforço , Tolerância ao Exercício , Feminino , Imagem do Acúmulo Cardíaco de Comporta , Humanos , Masculino , Pessoa de Meia-Idade , Volume Sistólico , Resultado do TratamentoRESUMO
A 31 year old man had a congenitally absent circumflex coronary artery, one of the least described of all the congenital abnormalities of the coronary arteries. Before confirmation of the diagnosis, an ectopie circumflex artery was excluded by the two angiographical signs observed by Page and by non-selective coronary arteriography. This abnormality was thought to have played a role in myocardial infarction in this young patient without coronary risk factors and with no obvious coronary artery narrowing on coronary arteriography.
Assuntos
Anomalias dos Vasos Coronários , Infarto do Miocárdio/etiologia , Adulto , Arteriopatias Oclusivas/diagnóstico por imagem , Doença das Coronárias/diagnóstico por imagem , Humanos , Masculino , RadiografiaRESUMO
The diagnosis of inferior myocardial infarction was wrongly made in a patient with a history of chest pain and Q waves in Leads 3 and aVF. Despite a normal PR interval, ventricular preexcitation was suspected on the deformation of the upstroke of the QRS complex, suggestive of a delta wave. Ventricular and coronary angiography and exercise Thallium 201 myocardial scintigraphy allowed the diagnosis of myocardial infarction to be eliminated. Endocavitary electrophysiological recordings confirmed the presence of an accessory atrioventricular conduction pathway (Kent bundle) and explained the intermittent appearances of the WPW syndrome on ECG. The patient was investigated after the acute episode, and the absence of cardiac enzyme estimations at that time made the rectification of the diagnosis more difficult.
Assuntos
Infarto do Miocárdio/diagnóstico , Síndrome de Wolff-Parkinson-White/diagnóstico , Adulto , Erros de Diagnóstico , Eletrocardiografia , Humanos , Masculino , Síndrome de Wolff-Parkinson-White/fisiopatologiaRESUMO
Prostacycline may play a preventive role in the development of ischaemic complications of coronary atherosclerosis through its vasodilatory and platelet antiaggregant properties. Its biological instability makes it difficult to measure in the plasma; however, it is possible to determine plasma concentrations by radioimmune assay of one of its stable derivatives, 6-Keto-prostaglandin F1 alpha (6KPGF1 alpha). Systemic plasma concentrations at rest of 30 patients with severe atherosclerosis were not significantly different from those of healthy control subjects (7.5 +/- 6.5 vs 10 +/- 5 pg/ml). In addition ischaemia during exercise is not associated with significant variations; at rest 7.1 +/- 6 pg/ml in the "ischaemic" group (n = 20) compared to 7.6 +/- 6.4 pg/ml in the "non-ischaemic" group (n = 10); on effort: 9 +/- 10 pg/ml compared to 13.3 +/- 14 pg/ml. These results show that measuring the plasma 6KPGF1 alpha by peripheral vein blood sampling is of no use in the diagnosis of coronary atherosclerosis or of myocardial ischaemia on effort.
Assuntos
6-Cetoprostaglandina F1 alfa/sangue , Doença das Coronárias/sangue , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esforço FísicoRESUMO
The tomographic mode has replaced the planar mode for radióisotopic studies of myocardial perfusion but not for the study of systolic ventricular function. The aim of this study was to compare monophotonic emission tomography (MPET), the planar mode (PM) and contrast angiography (Angio). The left ventricular volumes and ejection fractions were measured in 111 patients by the tomographic and planar modes and by biplane angiography in 70 of them. The MPET algorithm (QBS software) identified the ventricular endocardium in 96 of the 111 procedures (86%). The mean left ventricular ejection fractions (LVEF) were 57 +/- 17% (MPET, N = 96), 55 +/- 15% (PL, N = 96) and 57 +/- 15% (Angio, N = 70). There was a good correlation of LVEF between MPET and PL and MPET and Angio with negligible bias of 3 +/- 6% and 2 +/- 4% respectively and high correlation coefficients, r = 0.94 (MPET = 1.05*PL-0.2) and r = 0.93 (MPET = 1.1 x Angio-3). The differences between the 95% confidence intervals between MPET and PL and MPET and Angio may be explained by an overestimation of normal LVEF by MPET, especially in patients with low end systolic volumes. In these cases, the difference in LVEF by MEPT and the average LVEF from the 3 techniques was greater: 6 +/- 4% (< or = 20 ml) vs 0 +/- 3% (> 20 ml) (p < 0.0001). The authors conclude that, with the reserve that a high percentage of investigations could not be analysable. MPET seems to be a method of choice for assessing left ventricular systolic function.
Assuntos
Angiografia Coronária , Volume Sistólico , Tomografia Computadorizada de Emissão , Função Ventricular Esquerda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia Coronária/métodos , Humanos , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
ECG-gated Thallium 201 myocardial scintigraphy provides a simultaneous evaluation of left ventricular perfusion and function. The aims of this study were to determine the changes in left ventricular ejection fraction (LVEF) after exercise and at rest 4 hours after exercise and to compare the results with changes in myocardial perfusion and the severity of the coronary artery disease. Sixty-four men with myocardial ischaemia on scintigraphy who had undergone coronary angiography showing significant lesions within 3 months, were compared with 38 normal men. The ejection fraction was calculated with a validated programme (QGS). The change in LVEF between the post-exercise and resting measurement 4 hours after exercise (delta LVEF) was compared in the normal and ischaemic groups (+7 +/- 6.8% vs -5.6 +/- 5%, p < 0.001). The extent of the ischaemia (percentage myocardium unperfused) was significantly greater in the 34 patients who had an over 5% reduction in LVEF on exercise compared with the 30 others who has a less than 5% reductionin LVEF (11.8 vs 6.3%, p < 0.001). There was a linear correlation between the degree of ischaemia and delta LVEF in the 30 patients without a history of infarction (r = -0.76, p < 0.01). The delta LVEF also correlated with the number and site of the coronary lesions. The authors conclude that in this male population, ECG-gated Thallium 201 myocardial scintigraphy can demonstrate a decrease in LVEF after exercise in ischaemic coronary patients whereas it increases in normal subjects. This decrease in LVEF on exercise is correlated with the extent of ischaemia and the severity of the coronary disease and should therefore be taken into account in patient management.