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Biomedical subjects

A Englund

Publications and source records attributed to A Englund.

At least 19 recordsLinked to original sources

Diagnostic value of programmed ventricular stimulation in patients with bifascicular block: a prospective study of patients with and without syncope.

OBJECTIVES: The aim of this study was to examine the inducibility of ventricular arrhythmias in patients with bifascicular block both with and without a history of syncope and to relate the findings to clinical events during follow-up. BACKGROUND: Patients with bifascicular block have an increased risk of sudden death that is not reduced by pacemaker treatment. This risk could be related to a high incidence of ventricular arrhythmias. METHOD: Programmed ventricular stimulation was performed in 101 patients with bifascicular block: 41 had a history of unexplained syncope, and 60 were asymptomatic. RESULTS: Programmed ventricular stimulation resulted in a sustained ventricular arrhythmia in 18 patients (18%), 8 in the syncope group and 10 in the nonsyncope group (p = NS). Three patients in each group had an inducible sustained monomorphic ventricular tachycardia. During a mean follow-up of 21 months, 10 patients experienced a clinical event defined as sudden death (n = 4), syncope (n = 5) or appropriate discharges from an implantable cardioverter-defibrillator (n = 1). Only one of these patients had an inducible ventricular arrhythmia at baseline. CONCLUSIONS: The inducibility of ventricular arrhythmias is high in patients with bifascicular block and of the same magnitude in patients with and without a history of syncope. Clinical events during follow-up were not predicted by programmed ventricular stimulation in either of the two groups. The finding of inducible ventricular arrhythmia in patients with bifascicular block should therefore be interpreted with caution.

Adolescent

Use of signal-averaged electrocardiography for predicting inducible sustained monomorphic ventricular tachycardia in patients with bundle branch block with and without a history of syncope.

The aim of this study was to examine the utility of signal-averaged electrocardiography in relation to inducible sustained monomorphic ventricular tachycardia in patients with bundle branch block. One hundred fourteen patients with bundle branch block underwent signal-averaged electrocardiography in the time domain and programmed ventricular stimulation. Sustained monomorphic ventricular tachycardia was induced in 17 patients. The mean values of the three signal-averaged electrocardiographic variables analyzed differed significantly between the inducible and the noninducible group. The filtered QRS duration showed the most prominent difference between the two groups, and a filtered QRS duration > or = 155 msec had a sensitivity of approximately 80%, a specificity of 60%, and a total predictive value of 65%. In the subgroup of patients with syncope, a combination of these criteria with a history of coronary artery disease had a sensitivity of 100% and a specificity of 90%.

Aged

Spectral turbulence analysis of the signal-averaged electrocardiogram for predicting inducible sustained monomorphic ventricular tachycardia in patients with and without bundle branch block.

Spectral turbulence analysis of the signal-averaged electrocardiogram is a new method for identifying patients prone to sustained monomorphic ventricular tachycardia. In contrast to analysis in the time domain, it has been claimed to be applicable in patients with bundle branch block. The aim of this study was to assess the predictive value of spectral turbulence analysis, in relation to the inducibility of sustained monomorphic ventricular tachycardia, in patients with and without bundle branch block. One hundred and sixty nine patients, of whom 120 had a QRS duration > or = 120 ms, were studied. Forty-seven patients had inducible sustained monomorphic ventricular tachycardia and were compared to 122 control patients. The overall sensitivity of the spectral turbulence analysis for predicting inducible ventricular tachycardia was 77%, the specificity 35% and the total predictive accuracy 47%. The limited predictive accuracy was mainly due to a lack of difference between patients with and without ventricular tachycardia in patients with a QRS duration > or = 120 ms. In patients with QRS < 120 ms, however, there were significant differences in all spectral turbulence parameters and the method had a sensitivity of 75%, a specificity of 72% and a total predictive accuracy of 73%. The diagnostic usefulness of spectral turbulence analysis is dependent upon normal QRS duration and the method is applicable only to patients without bundle branch block.

Adult

Disopyramide stress test: a sensitive and specific tool for predicting impending high degree atrioventricular block in patients with bifascicular block.

OBJECTIVE: To study the value of intravenous disopyramide as part of an invasive electrophysiological study in predicting impending high degree atrioventricular block in patients with bifascicular block. DESIGN: An invasive electrophysiological study was performed in the basal state and after the infusion of disopyramide (2 mg/kg body weight). The progression to high degree atrioventricular block was assessed by bradycardia-detecting pacemakers or repeated 12-lead electrocardiogram recordings, or both. PATIENTS: 73 patients with bifascicular block were included, of whom 25 had a history of unexplained syncope. The remaining 48 patients had no arrhythmia related symptoms and were included as controls. All patients had an ejection fraction of > 35%. RESULTS: After a mean follow up of 23 months, seven patients in the syncope group and three in the non-syncope group had a documented high degree atrioventricular block or pacemaker-detected bradycardia of < or = 30 beats/min for > or = 6 s. The sensitivity of the disopyramide test was 71% and the specificity 98%. The corresponding figures for an abnormal electrophysiological study in the basal state were 14% and 91%, respectively. CONCLUSIONS: The sensitivity of an invasive electrophysiological study in patients with bifascicular block and syncope can be markedly increased by the use of intravenous disopyramide. A positive test is a highly specific finding and warrants pacemaker implantation.

Adolescent

Safety and health in the construction industry.

Workers in the building, renovation, and demolition of roads and commercial structures in the U.S. suffer a disproportionate share of occupational fatalities and lost-time injuries. Nearly all of the injuries and deaths are preventable. The fatality rate from work-related ailments, such as cancers and silicosis, is believed to be excessive, but is not generally computed. The safety and health problems are tied largely to the construction industry's organization and how the work is performed. Many hazardous exposures result from inadequacies in access to information, measurement technology, and personal protective equipment. Potential solutions are in labor-management site safety and health planning and management, education and training of workers and supervisors, new technologies, federal regulation, workers' compensation law, medical monitoring, and occupational health delivery. Public health opportunities involve health care delivery systems, improved preventive medicine, disability determination and rehabilitation programs, and research, beginning with the standardization of data to monitor these problems.

Accidents, Occupational

Smokeless tobacco use and increased cardiovascular mortality among Swedish construction workers.

OBJECTIVES: Little is known about the risks of cardiovascular disease associated with the use of smokeless tobacco, which produces blood nicotine levels similar to those caused by cigarette smoking. METHODS: Male Swedish construction industry employees (n = 135,036) who attended a health examination were followed by studying cause-specific mortality during a 12-year period. The study population comprised 6297 smokeless tobacco users, 14,983 smokers of fewer than 15 cigarettes per day, 13,518 smokers of 15 or more cigarettes per day, 17,437 ex-smokers, 50,255 "other" tobacco users, and 32,546 nonusers. RESULTS: The age-adjusted relative risk of dying from cardiovascular disease was 1.4 for smokeless tobacco users and 1.9 for smokers of 15 or more cigarettes per day, compared with nonusers. Among men aged 35 through 54 years at the start of follow-up, the relative risk was 2.1 for smokeless tobacco users and 3.2 for smokers. When data were adjusted for body mass index, blood pressure, and history of heart symptoms, the results were essentially unchanged. Cancer mortality was not raised in smokeless tobacco users. CONCLUSIONS: Both smokeless tobacco users and smokers face a higher risk of dying from cardiovascular disease than nonusers. Although the risk is lower for smokeless tobacco users than for smokers, the excess risk gives cause for preventive actions.

Adult

The risk of lung cancer from asbestos among Swedish construction workers: self-reported exposure and a job exposure matrix compared.

A total of 719 lung cancers were identified in a follow-up of 135,000 Swedish construction workers interviewed during 1971-1974 by occupational health nurses as part of a routine health check-up. These were analysed in a matched case-control study nested within this cohort, to compare different methods of characterizing exposure to asbestos. Self-reported exposure was contrasted with a job exposure matrix (JEM) of five levels of exposure intensity, applied to the job at the time of health check-up. Smoking adjusted odds ratios were computed and the JEM performed better than self-reported exposure, in being able to discriminate high risk subgroups. The same pattern was evident in a parallel analysis of 41 mesotheliomas. However both measures appeared subject to misclassification, and the question put seemed to pick up the use of asbestos cement products more effectively than asbestos insulation products. It is concluded that a simple JEM can be more reliable than a simple question, but that both should be much more detailed, to take account of different types of asbestos exposure and their variation over time.

Asbestos

A simplified assay for the specific diagnosis of paroxysmal nocturnal hemoglobinuria: detection of DAF(CD55)- and HRF20(CD59)- erythrocytes in microtyping cards.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease that is caused by a monoclonal stem cell defect. The affected cells lack the carbohydrate linkage between phosphatidylinositol and a group of membrane proteins of which three protect the cell against complement lysis. The absence of these three proteins, DAF(CD55), C8BP and HRF20(CD59), makes cells from the erythropoiesis, thrombopoiesis and myelopoiesis extensively sensitive to complement attack and affected patients suffer from intravascular hemolysis, thrombosis and increased susceptibility to infections. In this study we describe a swift and specific assay for the detection of CD55- and CD59- erythrocytes, which is suitable for screening of possible PNH patients.

Antigens, CD

Safety evaluation in both short- and long-term treatment of schizophrenia with remoxipride.

Results for laboratory and cardiovascular variables in both short-term (4-6 weeks) and long-term (greater than 6 weeks) double-blind studies in schizophrenic patients consistently showed comparably low incidences of both transient treatment-emergent changes and changes present at last rating for both remoxipride and haloperidol. The total incidence of serious adverse events in the short-term double-blind programme was approximately 2% for both remoxipride and haloperidol. The corresponding figure for remoxipride (n = 434) in long-term treatment was approximately 6%. Compared to those on haloperidol, fewer patients on remoxipride had trough plasma prolactin levels above the normal range in short-term treatment. The results with long-term treatment with remoxipride were similar. Breast swelling and galactorrhoea were infrequent treatment-emergent side effects with either drug. It was impossible to evaluate menstrual disturbance in short-term studies but in long-term use the incidence of treatment-emergent menstrual disorder was low in remoxipride patients. Too few patients continued treatment with haloperidol for a comparative long-term evaluation. Overall, based on the information available at present, remoxipride appears to offer a high degree of safety in both short-term and long-term treatment of schizophrenia.

Adult

Nasal and sinonasal cancer. Connection with occupational exposures in Denmark, Finland and Sweden.

A joint Danish-Finnish-Swedish case-referent investigation was initiated in 1977 in order to study the connection between nasal and sinonasal cancer and various occupational exposures. All new cases of nasal and sinonasal cancer were collected from the national cancer registers (Finland and Sweden) or from the hospitals (Denmark). Those still alive who agreed to an interview (N = 167) were individually matched for age and sex with patients with colonic or rectal cancer. A detailed telephone interview was made according to standardized forms. Both cases and referents thought that their condition was the one under study. The exposures were coded blindly by an industrial hygienist. The results showed associations between nasal and sinonasal cancer and exposure to (i) hardwood or mixed wood dust (discordant pairs 14: 2), (ii) softwood dust alone (13:4), (iii) chromium (16: 6), (iv) nickel (12: 5, not significant), (v) welding, flame-cutting and soldering (17: 6), and (vi) lacquers and paints (14: 0). The last finding was probably due to confounding from wood dust exposure. Hardwood dust exposure was associated with adenocarcinoma. Softwood dust exposure alone was associated with epidermoid and anaplastic carcinomas. No associations were found for a number of exposures, including agricultural chemicals, textile dust, asbestos, quartz dust, organic solvents and leather work. Possible exposure to formaldehyde was evenly distributed between the cases and referents.

Adenocarcinoma

Nasal cancer and occupational exposures. Preliminary report of a joint Nordic case-referent study.

Nasal and sinus paranasal cancers have been associated with several occupational exposures, for example, dust from hardwood, nickel and unspecific agents occurring in the boot and shoe industry. A joint Danish-Finnish-Swedish case-referent investigation was initiated in 1977 to study further the connection between nasal and sinus paranasal cancers and various occupational exposures. All new cases of these cancers were collected from the national cancer registers (Finland & Sweden) or from hospitals (Denmark). Those still alive who agreed to the interview (N = 167) were individually matched for age and sex with patients with colonic or rectal cancer. A detailed telephone interview was performed according to a standardized procedure. Both the cases and referents thought that their condition was the one under study. The exposures were coded blindly by an experienced industrial hygienist. The results showed associations between nasal or sinus paranasal cancer and exposure to hardwood or mixed wood dust (discordant pairs 14/2); softwood dust alone (13/4); chromium 16/6); nickel (12/5, not significant); welding, flamecutting, and soldering (17/16); and lacquers and paints (12/0). Hardwood dust exposure showed a connection with adenocarcinoma. Softwood dust exposure alone was associated with epidermoid and anaplastic carcinomas. No associations were found for a number of exposures, including agricultural chemicals, textile dust, asbestos, quartz dust, organic solvents, and leather work. Possible exposure to formaldehyde was evenly distributed between the cases and referents.

Adult

Retrospective cohort study of two plants in the Swedish rubber industry.

A cohort of 13,114 workers employed during 1930-1975 in two Swedish plants producing tires and industrial rubber goods was investigated with regard to cancer mortality and cancer incidence. Separate analyses were performed on the following subgroups of the cohort: mixers/weighers, other production workers, and white-collar employees. For all causes of death no increase of risk was observed in the population as a whole. Mixers/weighers showed however an increased overall standardized mortality ratio. The pattern of causes of death was not changed in the total cohort. An increased risk to die from liver cancer (risk ratio 4.12) and pancreatic cancer (risk ratio 2.70) was, however, observed for the category other production workers. An increased risk of death from tumors of the respiratory organs was also observed for the categories other production workers (risk ratio 1.89) and white-collar employees (risk ratio 2.63). For tumors in the urinary bladder (risk ratio 2.50) and for ischemic heart diseases (risk ratio 1.27) the death risk was elevated for the category other production workers. The cancer morbidity pattern showed an increase in malignant melanomas (risk ratio 2.50) for the category other production workers and for lung cancer (risk ratio 2.09), as well as for tumors in the nervous system (risk ratio 3.18) for white-collar employees.

Adolescent