title: Accuracy of left ventricular ejection fraction determined by the nuclear stethoscope.
abstract: We assessed left ventricular ejection fraction 47 times in 21 patients with sinus rhythm by a portable non-imaging nuclear probe. After 99mTc blood pool labelling, left ventricular ejection fraction was determined by probe in two different ways: on a beat-to-beat basis, and by the so-called ventricular function mode, based on the gated equilibrium principle, and subsequently compared with left ventricular ejection fraction measured by gated equilibrium radionuclide angiocardiography using a gamma camera. Left ventricular ejection fraction by probe correlated well with left ventricular ejection fraction by gamma camera: beat-to-beat versus gamma camera: r = 0.90, y = 0.75x + 0.12; ventricular function versus gamma camera: r = 0.88, y = 0.87x + 0.08. Also, left ventricular ejection fraction values determined by the two probe methods correlated closely: r = 0.97, y = 0.83x + 0.07. Compared with the gamma camera, the probe overestimated slightly the small values of left ventricular ejection fraction and underestimated high values. Correct determination of left ventricular ejection fraction by a non-imaging probe depends on correct positioning over the left ventricle and selection of a proper background activity level. The main application of this instrument is probably non-invasive bedside determination and monitoring of changes of left ventricular function occurring spontaneously or caused by cardiac arrhythmias or treatment with cardiac drugs.
mesh_terms: D000328:Adult; D000368:Aged; D000790:Angiocardiography; D002302:Cardiac Output; D003327:Coronary Disease / Q000503:physiopathology*; D005260:Female; D006326:Heart Auscultation; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D010781:Photography / Q000379:methods; D013318:Stroke Volume; D013667:Technetium
chemical_list: D013667:Technetium