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1.
Beta-adrenergic agonists have been shown to be capable of improving growth performance in poultry when added to the feed at 1.0 ppm. However, no reference has been made concerning the cardiovascular responses when one of these agents is added to the feed at a lower concentration during the whole production cycle. The aim of this paper was to assess the effects on the ascites syndrome of 0.25 ppm clenbuterol in the feed, throughout 52 d, in broiler chicks. Results showed a lack of difference in growth and feed conversion rate between the untreated control groups and the experimental group. There were differences in mortality due to the ascites syndrome, abdominal fat:body weight ratio, and ventricular index. A statistically significant positive correlation was also found between ventricular index and mortality rate (r = 0.98). If adequate withdrawal times are ensured, the use of clenbuterol at 0.25 ppm is suggested to reduce mortality due to the ascites syndrome in broilers.  相似文献   

2.
The challenge of preventing arrhythmic sudden death is one of the major issues in today's treatment of heart failure. To achieve this ambitious goal, an accurate selection of the candidates for sudden death is needed on the one hand, while on the other hand, the assessment of the real cost/benefit ratio of the implantable cardioverter-defibrillator in selected patients, as compared to ACE inhibitors, beta-blockers and antiarrhythmic drug therapy, should no longer be delayed. As is well known, the incidence of sudden death is higher in ischemic dilated cardiomyopathy than it is in non-ischemic dilated cardiomyopathy. Moreover, tachyarrhythmic sudden death is prevalent in NYHA classes I and II (80%), whereas its incidence is lower (50%) in NYHA classes III and IV, since bradyarrhythmia, electromechanical dissociation and thromboembolic events characterize the other 50% of sudden deaths in patients in the latter NYHA class. The stratification of arrhythmic risk in non-ischemic dilated cardiomyopathy is questionable from any point of view, considering the poor predictive power of invasive and non-invasive indexes. However, some subgroups of high-risk patients should be selected, such as patients waiting for heart transplant or those with a severe disease but without an extreme degree of ventricular dysfunction, in whom the prognosis in terms of pump failure events is better and life expectancy is longer if the risk of arrhythmia is properly assessed and sudden death prevented. Consequently, the ICD implant may be effective in order to pursue the aim of reducing the tachyarrhythmic and bradyarrhythmic mortality in patients with a more severe disease and of minimizing the tachyarrhythmic risk in those with a less severe disease. Further studies will be developed to identify the ideal candidates for ICD implants.  相似文献   

3.
OBJECTIVES: We investigated the long-term prognosis of completely asymptomatic adult patients with hypertrophic cardiomyopathy (HC). Diagnosis of HC was suspected because of an abnormal electrocardiogram and/or cardiac murmur and confirmed by echocardiography and/or left ventricular angiography, and hemodynamic investigation. BACKGROUND: Hypertrophic cardiomyopathy shows marked heterogeneity in clinical expression and prognosis. The prognosis of asymptomatic patients with HC has not been fully defined. METHODS: Of 128 consecutive adult patients with HC, 58 asymptomatic patients (Group 1, mean age 42.8 years) and 70 symptomatic patients (Group 2, mean age 50.4 years) were studied to assess cardiac mortality. Mean follow-up periods were 11.0 years for Group 1 and 9.1 years for Group 2. RESULTS: At presentation, Group 1 patients were younger and had smaller left atrial dimensions than did Group 2 patients. The annual cardiac mortality rate and the rate for sudden death alone in Group 1 were significantly lower than in Group 2 (0.9% vs. 1.9%, p < 0.05, 0.1% vs. 1.4%, p < 0.05, respectively). Although about one-third of the survivors in Group 1 had cardiac symptoms at their most recent evaluation, only one patient died suddenly compared with eight in Group 2. The annual mortality rate due to heart failure was similar in each group. Only a syncopal episode was associated with both cardiac death and sudden death for both groups combined. CONCLUSIONS: The cardiac mortality rate for completely asymptomatic adult patients with HC was very low, significantly lower than that of symptomatic patients, and there was a disproportionately low incidence of sudden death.  相似文献   

4.
Despite all advances in the diagnosis and therapy of cardiovascular diseases, the mortality from malignant ventricular tachyarrhythmias is still a major health problem. In addition to established therapeutic strategies in the prevention of sudden cardiac death such as antiarrhythmic drug treatment, catheter ablation or antiarrhythmic drug treatment, cardioverter/defibrillator was introduced to clinical practice in 1980. The number of 50,000 overall implants reflects the current clinical status of the therapy with implantable cardioverter/defibrillators. Significant technical improvements in the defibrillator therapy may contribute to an increase in therapy acceptance. These advances include the introduction of nonthoracotomy lead systems, enhanced defibrillation efficacy, full programmable devices providing tiered electrical therapy, improved diagnostic Holter functions and enhanced arrhythmia detection algorithms. The major present goals of defibrillator therapy are detection and termination of malignant ventricular tachyarrhythmias, prevention of sudden cardiac death, reduction in patient's mortality and improvement in quality of life. The efficacy and safety of defibrillator therapy to prevent sudden arrhythmic death has been proven in several large clinical investigations In patients with this device the annual sudden cardiac death mortality is < 2% even in high-risk patient populations. Compared to sudden cardiac death rate there is a much higher rate of overall cardiac mortality because a defibrillator is not able to prevent nonarrhythmic cardiovascular deaths. There is a clinical impression that cardiovascular mortality is lower in patients treated with an implantable cardioverter/defibrillator compared to patients treated with other therapies. However, there are no results from controlled studies providing scientific evidence that defribillator therapy can decrease overall cardiovascular mortality.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
Bone mass in 69 healthy girls in their period of growth spurt was measured twice, with an interval of one year, by dual energy X-ray bone densitometer to study the relationship between changes in bone density and the speed of height growth, development of secondary sex characteristics and nutritional status. Results showed that bone density in the different sites in the period of growth spurt increased significantly with their age, but with difference in the magnitude of its increase and in the time. Their nutritional status (overweight or underweight) correlated closely with sex development and increase in bone density. It suggests that it is necessary to strengthen nutrient intake during their puberty for preventing from osteoporosis. In addition, early puberty is an important period for the increase in female bone density, as a result of comparison of bone mass between prepuberty girls and young women. The results in this study can provide reference for further studies on bone mass in girls during their puberty.  相似文献   

6.
The gastrointestinal problems in cystic fibrosis (CF) may limit energy and nutrient availability and also cause symptoms such as abdominal pain and disturbed bowel habit which may further suppress appetite or alter the diet. Taken together this may lead to an inadequate supply of energy and nutrients to meet the nutritional requirements of the individual resulting in restricted growth or weight loss. A failure to optimize the digestive and absorptive capacity of the gastrointestinal tract places greater emphasis upon nutritional management by food intake alone. Practitioners need to focus more on gastrointestinal dysfunction in CF and its impact upon food intake in order to improve the efficacy of nutritional management. Refined stable isotopic tracers allow further exploration of the pathophysiology of the gastrointestinal tract in terms of nutrient availability. In clinical practice, a closer assessment of gastrointestinal function is supported by the use of simple, noninvasive tools which, both objectively and systematically, characterize those patients who have problems.  相似文献   

7.
OBJECTIVE: To evaluate the value of QT interval as a cardiac risk factor in middle aged people. METHODS: The association between QT interval and cardiac risk factors and mortality in a middle aged Finnish population of 5598 men and 5119 women was evaluated over a 23 year follow up. To adjust the QT interval confidently for heart rate, a nomogram was constructed from the baseline electrocardiograms separately for men and women. RESULTS: Nomogram-corrected QT interval (QTNc) prolongation was associated with elevated blood pressure and signs of cardiovascular disease; QTNc shortening was associated with smoking. Over 10% prolongation of QTNc predicted death in men with heart disease: adjusted relative risk (RR) was 2.17 (95% confidence interval 0.67-7.45) for sudden death; 2.12 (1.25-3.59) for total cardiovascular mortality; and 1.92 (1.23-3.00) for all cause mortality. In healthy men the increase in RR was not significant: sudden death, 1.48 (0.67-3.25); total cardiovascular mortality, 1.25 (0.92-1.70); all cause mortality, 1.21 (0.96-1.53). However, healthy men with long QTNc in the lowest heart rate quartile exhibited an RR of 2.75 (1.00-7.40) for sudden death. Over 10% shortened QTNc predicted cardiovascular death in men with heart disease who smoked; RR 3.72 (1.45-9.54). Non-smoking men with short QTNc had low mortality risks irrespective of possible signs of cardiovascular disease. The trends in mortality risks were similar but weaker for women. CONCLUSIONS: In a middle aged population, prolonged QT interval predicts cardiac mortality in men with signs of cardiovascular disease. In women and healthy men this risk is weak and may reflect subclinical heart disease. A shortened QT interval predicts death in men with heart disease who smoke.  相似文献   

8.
BACKGROUND: Most of the information available on the clinical course and prognosis of hypertrophic cardiomyopathy (HCM) is based on data generated from international referral centres and as a result, it constitutes a potentially biased perspective of the disease process in this complex and diverse condition. A multicentric study was therefore set up with the aim of providing information on unselected patient populations with HCM. METHODS: The study group comprised 330 patients from 5 non-referral hospitals (mean age 42 +/- 16 years, M/F 226/104, 74-22%-obstructive, 299-91%-in NYHA class I-II) who were followed up regularly for 9.5 +/- 5.6 years. RESULTS: The vast majority of patients (n = 272, 82%) remained asymptomatic or mildly symptomatic during the follow-up period, whereas the remaining patients (n = 58, 18%) experienced clinical deterioration or died. Of the 18 patients (5%) who died of cardiovascular causes related to hypertrophic cardiomyopathy, 14 had progressive congestive heart failure and only 4 died suddenly. The annual mortality rate for cardiovascular disease was 0.57%, while the mortality rate due to sudden cardiac death was only 0.1%. The cumulative survival rate was 98, 95 and 93%, at 5, 10 and 15 years of follow-up respectively. Atrial fibrillation proved to be a relatively common (n = 81, 24%) and particularly unfavourable clinical feature, with higher mortality rate for cardiovascular causes related to hypertrophic cardiomyopathy. Syncope occurred in 47 patients (14%) but did not appear to have prognostic significance. CONCLUSIONS: In an unselected population, hypertrophic cardiomyopathy had a relatively benign prognosis that was inconsistent with its prior characterization as a generally progressive disorder, based primarily on the experience of selected referral institutions. Sudden unexpected cardiac death was distinctly uncommon, although a sizable proportion of patients, particularly the subset prone to atrial fibrillation, did experience clinical deterioration.  相似文献   

9.
The history of the use of beta-blockers for congestive heart failure, beginning with the innovative seminal study by the Swedish group in 1975 to studies in 1995, is reviewed and shows that almost all trials favored the use of beta-blockers. They tended to demonstrate an increase in ejection fraction, a decrease in left ventricular mass, and in some studies, even a decrease in mortality. Even after the introduction of angiotensin-converting enzyme inhibitors, additional improvement in function and mortality was observed. Patients with nonischemic dilated cardiomyopathy derived more benefit from beta-blockers than did patients with ischemic cardiomyopathy. Least likely to benefit were patients treated for <2 months, patients with alcoholic cardiomyopathy, and those with marked intercellular fibrosis. Although the starting dose of metoprolol, the most common beta-blocker used, may have to be as low as 2.5 mg/d, mortality analysis failed to show a decrease in sudden death unless the dose was raised to about 300 mg/d, a dose at which beta-selectivity is generally not expected to be present. The non-beta-specific bucindolol or carvedilol may ultimately be preferred to metoprolol because they are better tolerated initially due to a slight vasodilatation effect. Initial studies with carvedilol showed remarkable promise in reducing mortality. However, these agents cannot yet be said to have been studied adequately.  相似文献   

10.
BACKGROUND: At the beginning of 1994, five cases of sudden infant death syndrome after DTP immunization appeared in Spain. In order to study a causal relationship a meta-analysis of the different studies that assess this possibility has been conducted. METHODS: The selection criteria was epidemiological study, case-control or cohort, assessing risk of sudden infant death syndrome in immunized versus non-immunized infants or risk of sudden infant death syndrome in recently immunized infants versus immunized infants beyond 30 days. Pooled risk ratios were calculated from adjusted risk ratios, when available, of the different studies, by a meta-analysis according the method described by Greenland. RESULTS: One cohort and four case-control studies were selected. Pooled risk ratio for immunized versus non-immunized infants was 0.67 (95% CI = 0.60-0.75). When comparing risk of sudden death syndrome in up to 30 days immunized infants versus more than 30 days immunized infants, the pooled risk ratio was 1.00 (95% CI = 0.84-1.20). CONCLUSIONS: DTP-immunization does not seem to increase the risk of sudden infant death syndrome. The risk of sudden infant death syndrome is not greater in the first thirty days following immunization. These data indicate a lack of association between DTP immunization and sudden infant death syndrome.  相似文献   

11.
Design of diets for the study of dietary influences in mammary gland carcinogenesis requires attention to several questions: (1) Do the diets satisfy the nutritional needs of the animal under the conditions of the experiment, and are they palatable? (2) Does the protocol include determination of feed intake (if indicated) and of achievement of the desired level of nutrient deficiency, adequacy, or excess? (3) Are there potentially confounding nutrient interactions or nutrient effects or physiological or pathological responses that must be considered? The particular sensitivity of mammary gland tumorigenesis to intake of fat and calories and to body weight gain must be considered and controlled for in all experiments.  相似文献   

12.
Aborted sudden death as the presenting manifestation of hypertrophic cardiomyopathy in a 14-year-old child is reported. Documented ventricular fibrillation was the cause of cardiac arrest. No ventricular arrhythmia was induced during programmed electrical stimulation. An implantable cardioverter-defibrillator was indicated. As the patient had a family history of myocardial disease, he had undergone a cardiovascular evaluation 4 years before the major event, and was found normal. It is suggested that normal physical examination, ECG, echocardiogram should not rule out the diagnosis of hypertrophic cardiomyopathy when a family history is present. Left ventricular hypertrophy may develop during childhood in patients with hypertrophic cardiomyopathy.  相似文献   

13.
The relationship between nutrient intake and bone mineral density (BMD) in a community of healthy elderly women was investigated. A three-day nutritional survey was carried out. Subjects were divided into two groups using criteria set by the Recommended Dietary Allowances for the Japanese Fifth Revision (1994). Relationship between nutritional intake and BMD was explored. Intake of energy, protein, fats, and vitamins B1 and B2 correlated positively with BMD, as did the intake of eggs, meat, legume and soya products, other vegetables and potatoes, as well as fat and oil. Those with larger average number of food ingested per day had higher average of BMD. In conclusion, the hypothesis: adequate dietary intake protects against BMD loss, agreed with the results. Sufficient nutrient and food intake is associated with BMD increase, and possibly reduced risk of osteoporosis.  相似文献   

14.
The present report analyzes the prevalence of the cluster of metabolic abnormalities defined as syndrome X (high blood glucose, high blood pressure, low high density lipoprotein (HDL) cholesterol, and high triglycerides) and its impact on cardiovascular disease mortality in a large cohort of men and women (22,561 men and 18,495 women). These individuals were participants in a series of epidemiologic investigations of cardiovascular disease conducted in Italy between 1978 and 1987. They were followed for an average of 7 years, during which time a total of 1,218 deaths occurred (1,003 in men and 215 in women). Deaths were coded according to the International Classification of Diseases, 9th Revision (ICD-9). The prevalence of the full cluster of metabolic abnormalities (syndrome X) was low in the population as a whole, with only 3.0 percent of men and 3.4 percent of women exhibiting the full cluster of abnormalities that comprise syndrome X. The risk of death from all causes and cardiovascular disease increased with increased numbers of metabolic abnormalities in both men and women. Mortality from cancer was significantly increased in women (but not in men) with syndrome X, compared with women with no metabolic abnormalities. Population attributable risks for all cause mortality and cardiovascular disease mortality were 0.06 and 0.09 in men and 0.04 and 0.48 in women when assessed by population cutpoints. These data from a large population-based epidemiologic investigation indicate that the presence of a full cluster of metabolic abnormalities from syndrome X is an important risk factor for cardiovascular disease and all-cause mortality in both men and women, but that the low prevalence of such a cluster in the population reduces the public health impact of syndrome X. The majority of individuals who die from cardiovascular disease present elevations in any one, two, or three of the metabolic abnormalities. The notion of the cluster of metabolic abnormalities (syndrome X) should not distract our attention from established individual risk factors that have been proven to be major causes of cardiovascular disease death and disability in our society.  相似文献   

15.
BACKGROUND: Implantable cardioverter-defibrillators have been infrequently used in children as therapy for resuscitated sudden death and syncope due to ventricular arrhythmias unresponsive to antiarrhythmics. METHODS: The medical records of 5 children with implantable cardioverter-defibrillators were retrospectively reviewed. All patients had experienced syncope and 3 (60%) an out-of-hospital cardiac arrest. Underlying pathology included hypertrophic cardiomyopathy in 2, long QT syndrome in 2, and ventricular arrhythmia after remote repair of congenital heart disease in 1. Open thoracotomy with epicardial lead placement and transvenous endocardial approaches were used. RESULTS: There was no early or late mortality in the 5 pediatric patients undergoing implantable cardioverter-defibrillator placement. Postoperative complications occurred more frequently when open thoracotomy was used for placement. At mean follow-up of 34 months, 4 of the 5 (80%) have received shocks. CONCLUSIONS: Implantable cardioverter-defibrillator is a safe and reliable therapy for children with resuscitated sudden death and syncope due to ventricular tachycardia unresponsive to antiarrhythmics. Transvenous lead placement lowers morbidity and hospital length of stay.  相似文献   

16.
Cardiovascular diseases and cancers constitute major public health problems in all industrialized countries, where they are the main causes of premature mortality. There is a large body of evidence suggesting that free-radical production can directly or indirectly play a major role in cellular processes implicated in atherosclerosis and carcinogenesis. Here we present mechanistic data and results of epidemiologic studies on the relationship between antioxidant vitamin intake or biochemical status and the risk of cancer and cardiovascular diseases. Most epidemiologic data obtained on this topic were based on an observational approach, i.e., ecologic, case-control, or prospective studies. All these studies indicate that a high dietary intake or high blood concentrations of antioxidant vitamins are associated with a reduced risk of cardiovascular diseases and cancer at several common sites. Although the results of these studies are convergent, they merely suggest a relationship at the population and individual level but do not affirm a causality link. Only intervention studies (randomized trials), by specifically changing antioxidant vitamin intake, can provide conclusive answers. The apparent discrepancies between the results of four recently published trials may be explained by the type of population (general or high-risk subjects), the differing doses of supplementation (nutritional levels or higher), the number of antioxidants tested (one, two, or more), and the type of administration (alone or in balanced association). It thus appears that a low risk of pathologies may be related to multiple nutrients consumed at nutritional doses and in combination. Optimal effects may be expected with a combination of nutrients at levels similar to those found in a healthy diet. A single antioxidant vitamin given at high doses in subjects with high risk of pathologies (smokers, asbestos-exposed subjects) may not have substantial benefits and could even have negative consequences.  相似文献   

17.
Excessive specialization and high production requirements place high demands on the metabolism of poultry. A number of metabolic problems, such as disturbances of energy metabolism (affecting mainly hens) and mineral balance (affecting mainly laying hens), affect performance. Nearly all these problems are multifactorial in nature, but diet, and in particular the interaction between diet and phenotype, plays an important role. The problem of ascites in broiler hens is discussed in relation to external and genetic causative factors. Genetic factors can be further subdivided into structural and functional causative factors. This distinction has important consequences. For example, sudden death syndrome can be distinguished as a separate entity. Fatty liver syndrome in laying hens, and gout and urolithiasis in chicks and hens are briefly discussed. Finally, some of the most important or most common skeletal problems affecting poultry, namely, tibial dyschondroplasia, battery fatigue, rickets, and chondrodystrophy, are briefly discussed in the context of the dietary factors that underlie these disorders or which can be used as treatment.  相似文献   

18.
Hypertrophic cardiomyopathy is the most common cause of sudden death in young individuals who are otherwise healthy. Risk of sudden death is highest in patients who are between 14 and 35 years old. Several mechanisms are involved in sudden death: ventricular arrhythmias, supraventricular arrhythmias leading to cardiac collapse, bradycardias and severe ischemia. Many studies have analyzed how to identify high risk patients. The factors that best identify high risk patients are: previous history of sudden death or syncope, induction in adults of sustained ventricular arrhythmias, the presence of non-sustained ventricular tachycardia in symptomatic patients, the presence of ischemia associated with hypotension in children, the presence of mutations in the beta-myosin heavy chain together with a family history of sudden death and a poor left ventricular ejection fraction. Risk stratification should be done on an individualized basis. In those patients in whom a high risk for sudden arrhythmic death is suspected, the only current effective treatment is the implantable defibrillator.  相似文献   

19.
We report on a 30-year-old man with progressive cardiomyopathic lentiginosis. This syndrome is first described by Polani and Moynahan 1972. They distinguish between the earlier described multiple lentigines syndrome, the LEOPARD syndrome (L-entiginosis, E-lectrocardiographic conduction defects, O-cular hypertelorism, P-ulmonary stenosis, A-bnormalities of genitalia, R-etardation of growth, D-eafness) and the progressive cardiomyopathic syndrome. The progressive cardiomyopathic syndrome is characterised by multiple symmetrical lentigines, hypertrophic obstructive cardiomyopathy and retardation of growth. All characteristics were present in our patient with only mild right ventricular hypertrophic cardiomyopathy.  相似文献   

20.
Recent studies have reported ECG anomalies and a high prevalence of exercise-related arrhythmias among well trained, apparently healthy endurance athletes with superior levels of cardiorespiratory fitness. The occurrence of sudden and premature cardiac deaths in amateur and professional athletes, who appear to embody all of the virtues of health and fitness, ahs raised our consciousness regarding the underlying atherosclerotic or nonatherosclerotic causes, and the need for, and extent of, preparticipation screening in competitive athletes. It appears that strenuous physical activity may trigger acute cardiovascular events in some athletes. Coronary artery disease is the most frequent autopsy finding in those over the age of 35 years who die suddenly. In contrast, structural cardiovascular abnormalities, including hypertrophic cardiomyopathy and malformations of the coronary arteries, are the major cause of sudden death in younger athletes. This article reviews these issues, with specific reference to the assessment of cardiorespiratory fitness, legal and prohibited performance-altering medications, the pathophysiological basis of exertion-related untoward events, the athlete at risk, limitations of conventional screening programmes and contemporary recommendations to identify latent cardiovascular disease in athletic populations.  相似文献   

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