CA Howie

The predictive value of the measurement of changes in ST segment elevation was assessed as a non-invasive marker of coronary artery reperfusion after thrombolytic treatment. Forty five patients with acute myocardial infarction (23 anterior, 22 inferior) of less than six hours' duration were given thrombolytic treatment by either the intravenous (n = 28) or the intracoronary route (n = 17). A proportional value for the shift in ST segment, termed the fractional change, was calculated both from 12 lead electrocardiograms and from the Holter tape for each patient. Coronary artery patency in an initial group of 22 patients (training group) was associated with a fractional change value of greater than or equal to 0.5 (100% specific, 88% sensitive by Holter analysis; 100% specific, 94% sensitive by 12 lead electrocardiogram). This rule performed well when it was applied to a test group of 17 patients (100% specific, 93% sensitive by Holter analysis; and 67% specific, 93% sensitive by 12 lead electrocardiogram). Linear discriminant analysis was then used to determine which features gave the best separation of those in whom there was reperfusion and those in whom there was not. This gave 100% specificity and 100% sensitivity when applied to the training group for either the 12 lead electrocardiogram or Holter monitoring. When it was applied to the test group, the sensitivity was maintained at 100%, but the specificity dropped to 33% irrespective of whether the basis of the test was Holter monitoring or the 12 lead electrocardiogram. These results suggest that a fractional change of >/= 0.5 calculated from a single lead showing myocardial injury is a useful non-invasive marker of reperfusion. The technique can be applied to either 12 lead electrocardiograms or Holter monitoring. The use of a more complex classification increased the sensitivity of the test at the expense of its specificity.

BACKGROUND: It is still not certain whether it is worth using theophylline in addition to inhaled bronchodilators and corticosteroids to treat obstructive airways disease. This trial was designed to test whether the addition of prescribed theophylline in doses sufficient for sustained optimal steady state plasma concentrations would produce any detectable additional advantage in spirometric or functional variables in these handicapped patients. METHODS: A randomised, double blind, placebo controlled, crossover study of added theophylline treatment was aimed at steady state plasma concentrations of 10 and 17 mg/l, the dose being calculated individually by Bayesian parameter estimation and maintained for six weeks along with the patient's previously prescribed bronchodilators and steroids. Of 20 patients sequentially recruited, 15 provided data that could be analysed. All had chronic obstructive lung disease with a mean forced expiratory volume in the first second (FEV1) up to about 30% of the predicted value and gave no history of being treated with theophylline. The protocol included spirometry, whole body plethysmography, and treadmill exercise. Measurements also included steady state plasma theophylline concentrations and trapped gas volume. Quality of life was assessed by an established questionnaire method covering breathlessness in everyday activities, fatigue, emotional function, and control over the disease. RESULTS: Both target plasma concentrations were achieved. Improvements in peak flow (PEF; mean 20%), trapped gas volumes (38%), two stage vital capacity (15%), distances walked (48%), breathlessness in everyday activities (32%), and fatigue (18%) were found at the higher plasma concentration only. FEV1, forced vital capacity (FVC), emotional function, and control did not change. CONCLUSION: Theophylline treatment with sustained steady state concentrations about 17 mg/l provides worthwhile objective and subjective further benefits for patients handicapped by chronic obstructive lung disease when it is added to bronchodilators and corticosteroids.

significant trends over time in average daily intake of either energy or fat, determined by weighing food intake for seven days.