Computed tomography in patients with hypertrophic cardiomyopathy.

Abstract

SUMMARY Computed tomography was undertaken in nine patients (age range 33-69 (mean 48.7) years) with hypertrophic cardiomyopathy. The ventricular septum was demonstrated in each patient and shown to be thickened ( (Conray 420) were then injected into a large peripheral arm vein, 30 ml as a bolus and the remaining 20 ml more slowly during the next 20 s. The first scan was obtained immediately after the bolus, again at full inspiration. Five further contrast enhanced images were then obtained as rapidly as possible during the next minute. Our machine has a 5 s interscan time thus allowing normal respiration between scans. The six postcontrast images were obtained at 5 mm anatomical increments so that there was every chance of getting at least two satisfactory images of the septum. In some patients an attempt was made to align the plane of the scan to the long axis of the heart by gantry angulation after an initial lateral scanogram.Measurements of septal thickness were subsequently made with electronic calipers on the evaluation console. A standard window width (256 Hounsfield Units) was used for viewing. The level was then adjusted until the contrast medium in the chambers was in the middle of the grey scale (often around + 100 HU). ResultsThe