Keywords: open access echocardiography, rapid access echocardiography, echocardiography, heart failure, valvular heart disease, hypertension D ue to the ageing population, the general practitioner will see more patients with symptoms of dyspnoea. 1,2 For the general practitioner, with his limited diagnostic facilities, it is frequently very difficult to distinguish between dyspnoea due to cardiac and non-cardiac causes. 3 Dyspnoea can be due to systolic or diastolic dysfunction, but can also be caused by pericardial disease, hypertension and non-cardiac abnormalities.Often, a normal electrocardiogram or a low brain natriuretic peptide (BNP) level can exclude left ventricular dysfunction. Unfortunately, the positive predictive value of both methods is not very high. 4,5 Electrocardiograms have a positive predictive value of 35% and a negative predictive value of 98% to detect or exclude heart failure. Measurement of plasma BNP gave a positive predictive value of 5 to 38% depending on the cut-off point and a negative predictive value of 92 to 100% in the Framingham Heart Study. 5 If there is still doubt about the aetiology of dyspnoea, echocardiography can help to differentiate between a cardiac cause and a non-cardiac cause. Besides this, it can also provide information about structural abnormalities that cause dyspnoea in certain patients. In an older population, not only the number of patients with heart failure increases, but also the incidence of hypertension and murmurs of unknown aetiology will rise. A correct diagnosis is not easy despite an extensive physical examination and auscultation. 6,7 Therefore, in the very south-east of the Netherlands (the Parkstad area) general practitioners were given the opportunity to ask for an echocardiogram without referring the patient to the department of cardiology. This was for
The performance characteristics of two bone alkaline phosphatase (ALP; EC 3.1.3.1) assays, a wheat germ agglutinin (WGA) precipitation assay and a new immunoadsorption assay (IAA), were compared. The within- and between-run imprecision of the IAA (3.6-4.2% and 3.6-7.7%) was comparable with that of the WGA assay. The mean cross-reactivity with liver ALP appeared to be 4% in the WGA assay and 11% in the IAA. The reference ranges in a group of 155 healthy Caucasian (pre)pubertal schoolgirls were: 149-401 U/L (total ALP, 30 degrees C), 105-349 U/L (bone ALP, 30 degrees C, WGA assay), and 58-205 U/L (bone ALP, 25 degrees C, IAA). Comparison of the WGA assay (x) with the IAA (y) demonstrated a correlation coefficient of 0.95 [Deming regression equation: y = (0.56 +/- 0.01)x + (2.0 +/- 1.5); Sy[symbol: see text]x = 5.3 U/L]. Correlation studies of the WGA assay and the IAA results with total ALP demonstrated r = 0.98 and 0.96, respectively.
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