Clinical physiology (Oxford, England)
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Comparative Study Clinical Trial
Detection of patent foramen ovale by transcranial Doppler and carotid duplex ultrasonography: a comparison with transoesophageal echocardiography.
Patients who have suffered a transient ischaemic attack or minor stroke are examined thoroughly to determine the aetiology of the cerebrovascular incident. An examination of the carotid arteries is compulsory to detect significant stenosis. In some patients, cardiogenic sources of emboli may be suspected. ⋯ In the group without a PFO, microbubbles were detected in the ICA in one patient and in the MCA in two. This corresponds to a sensitivity and specificity, respectively, of 58% and 91% for the ICA/duplex technique and 100% and 82% for the MCA/transcranial Doppler technique. From this limited sample, it is shown that transcranial Doppler monitoring of the middle cerebral artery, but not ultrasound duplex monitoring of the internal carotid artery, can be used as screening for patent foramen ovale.
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We examined the effects from subjects, technicians and spirometers on within-session variability in successful recordings of forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in 4989 asymptomatic never-smoking men. All eligible men aged 30-46 years living in western Norway (n = 45,380) were invited to a cross-sectional community survey. Information on respiratory symptoms, smoking habits and occupational exposures was obtained from a self-administered questionnaire. ⋯ In conclusion, within-subject variability in three successful spirometric recordings was small, but dependent on height and BMI of the subjects as well as technician performance. The observed heterogeneity in between-subject variation in FEV1 and FVC levels disappeared when each variable was divided by height squared. Novel multiple linear regression equations for FEV1/height2 and FVC/height2 were developed to be used in evaluating the effects from occupational airborne exposures in Nordic men aged 30-46 years.