[Continuous ambulatory measurement of left ventricular function by an isotopic method].

Ambulatory cardiac radionuclide monitoring is a relatively new technique of non-invasive assessment of left ventricular function. This technique, which uses a portable gamma-ray detector, enables continuous recording over a number of hours of global left ventricular ejection fraction after red cell labelling with technetium. The detector is placed in contact with the skin over the apical region in a 45 degrees left anterior oblique view. Adequate collimation enables the variations in left ventricular volume during the cardiac cycle to be quantified and the ejection fraction to be deduced without having to generate an image. The authors review this method and describe the different available systems. They may be classified in two groups as to whether the technique is limited to continuous bed-side monitoring or if used for ambulatory monitoring (the only commercially available model being the Vest). Validation studies and trials in normal subjects are envisaged. The information acquired by this new method is analysed in the different clinical fields: post-infarction, stable angina, asymptomatic coronary artery disease, hypertension. The role of this new technique in the investigation of coronary artery disease is discussed with respect to other non-invasive techniques. The limitations of the technique and the material are reviewed and possible future developments are described.