Comparison of radionuclide angiography with three echocardiographic parameters of left ventricular function in patients after myocardial infarction.

AIMS: Left ventricular function is an important outcome measure in patients with coronary artery disease, in particular in patients after myocardial infarction. It is reliably assessed by radionuclide angiography, but echocardiographic wall motion scoring might be an attractive alternative. METHODS: Four days after reperfusion therapy for acute myocardial infarction both radionuclide angiography and echocardiography were performed in 90 patients. Segmental wall motion scoring (WMSI) and visual estimation of the left ventricular ejection fraction (LVEF) was done by 2 independent observers. Repeated analysis was performed 1 month after the first reading. In 41 patients the LVEF was assessed quantitatively by tracing of endocardial outlines of the left ventricle. RESULTS: Both correlation with radionuclide angiography (estimated LVEF: r = 0.71, WMSI: r = -0.68, Tracing: r = 0.59) and inter- and intra-observer variability (estimated LVEF: 19% and 15%, WMSI: 65% and 59%) were in favour of the LVEF estimation method. Correlation with radionuclide angiography measurements was related to the quality of the echocardiogram and to the extent of coronary artery disease. CONCLUSION: Simple echocardiographic estimation of left ventricular ejection fraction in patients after reperfusion therapy for acute myocardial infarction proved to be superior to quantitative assessment of ejection fraction and to segmental wall motion scoring in comparison with radionuclide angiography.

Reproducibility of left ventricular size, shape and mass with echocardiography, magnetic resonance imaging and radionuclide angiography in patients with anterior wall infarction. A plea for core laboratories.

After myocardial infarction, left ventricular volume and ejection fraction can be assessed by echocardiography, magnetic resonance imaging and radionuclide angiography to guide therapy and determine prognosis. Whether a measured parameter gives the same results irrespective of the method used and the observer who performs the analysis is only partly known. Intra-observer and inter-observer variability were determined for echo and magnetic resonance imaging. Left ventricular ejection fraction measured by these techniques was related to radionuclide angiograms performed in the same period. Intra-observer variability for both echo and MRI was low and in most instances below 5%. Inter-observer variability for the echo and MRI measurements were substantially higher than intra-observer variability. Comparison of the three imaging modalities revealed systematic differences. Therefore, in clinical studies, left ventricular volume and function parameters have to be measured with the same technique and by the same observer in qualified core laboratories.

Relevance of pretransfusion incubation of platelets at 37 degrees C.

The effect of pretransfusion incubation of platelets at 37 degrees C was assessed because of the controversial reports about its relevance. A dual-label technique (111indium and 114mindium) was applied in 10 healthy subjects receiving warmed and unwarmed autologous platelets simultaneously. Fresh platelet concentrates were infused into five subjects, whereas the other five subjects received stored platelet concentrates. The mean platelet volume decreased in all platelet concentrates during incubation, reflecting the restoration of the discoid shape of the platelets. The mean decrease was 0.35 fL (P = .003). However, the initial recovery and the mean platelet life-span were not improved by this procedure. It was concluded that there is no evidence that brief warming of platelets has any beneficial effect on platelet viability in healthy volunteers.

Acute renal failure in severe chloroquine resistant falciparum malaria.

We observed 3 patients with a severe falciparum malaria infection. Although the patients appeared not to be seriously ill on admission, severe complications occurred. Renal impairment was a prominent feature and haemodialysis was sometimes necessary. Many hypotheses have been proposed regarding the aetiology of renal failure in Plasmodium falciparum but cannot yet be fully substantiated. Whatever the aetiology of renal failure might be, we believe that treatment should not differ essentially from that of acute tubular necrosis after circulatory shock and early diagnosis and treatment is imperative in spite of an initially ostensibly good clinical condition.

Two devices for longitudinal emission tomography of the thyroid.

Two devices especially designed for tomographic thyroid imaging are compared on the basis of phantom experiments and four patients studies: a seven pinhole (7P) collimator and a time-coded aperture (TCA). The results of patient studies show that the 7P collimator may miss smaller abnormalities and is prone to incorrect positioning. The TCA reconstructions of patient data confirm the good performance observed in the phantom studies and demonstrate a high degree of lesion detectability. The TCA also provides higher efficiency and shorter imaging times than the 7P collimator. It is therefore concluded that TCA imaging is a promising alternative to multiple view pinhole imaging of the thyroid.