Tissue characterization by magnetic resonance imaging in hypertrophic cardiomyopathy.
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Cardiomyopathy, Hypertrophic↗
Biomedical subjects
D Wahr
Publications and source records attributed to D Wahr.
Left ventricular mass and volume/mass ratio determined by two-dimensional echocardiography in normal adults.
This study prospectively defined the range of left ventricular mass and volume/mass ratio determined by two-dimensional echocardiography in 84 normal adults. A modified Simpson's rule algorithm was used to calculate ventricular volumes from orthogonal two and four chamber apical views. An algorithm based on a model of the left ventricle as a truncated ellipsoid was used to calculate ventricular mass. Like left ventricular volumes, left ventricular mass values were larger in normal men than in women (mean 148 versus 108 g, p less than 0.001) and remained larger after correction for body surface area. Volume/mass ratios, however, were constant at end-diastole (0.80) and end-systole (0.26). The influence of age and heart rate on all variables in this normal group was minimal, and no correction for these variables was necessary. The definition of normal mass, volume and volume/mass ratios by two-dimensional echocardiography will facilitate the noninvasive, quantitative diagnosis of left ventricular hypertrophy and help clarify the relation between hypertrophy and systolic wall stress.
Adult↗
Atrial volume in a normal adult population by two-dimensional echocardiography.
Left atrial (LA) and right atrial (RA) volumes were calculated from two-dimensional echocardiography (2D echo) in 54 normal volunteers, of whom 23 were nonathletic men and 25 nonathletic women; 6 additional men had a history of athletic training. Ages ranged from 20 to 66 years (average nonathletic group, 38 years; athletic men, 28 years). The LA volume was measured by single-plane area-length algorithm from apical 2-chamber (2CH) and 4-chamber (4CH) views and from their combination by means of Simpson's rule. The RA volume was analyzed only in the 4CH view. Mean LA volume was larger for men than women; for nonathletic men, 46 +/- 14 ml for 2CH view and 38 +/- 10 ml for both the 4CH view and for Simpson's rule combination of the apical views. For women it was 36 +/- 11 ml for the 2CH view, 34 +/- 12 ml for the 4CH view, and 32 +/- 10 ml by Simpson's rule. Right atrial volume was 39 +/- 12 ml in nonathletic men and 27 +/- 7 ml in women. In the six athletic men, LA volume and volume index, but not RA volume and volume index, were significantly larger than in nonathletes. These findings in this small sample suggest that caution should be exercised in interpreting atrial enlargement in athletes. There were no significant correlations between atrial volumes and age, although individuals over 65 years with normal hearts were not represented. In evaluating LA volume in a given patient, it is advisable to use specific values for each apical view and algorithm and to correct for either sex or body surface area (BSA) but not for both. In the RA it is necessary to correct for both sex and BSA.
Adult↗
Normal left atrial function determined by 2-dimensional echocardiography.
To obtain normal values for left atrial function noninvasively, volumes of the left atrium and ventricle were calculated in 52 volunteers by 2-dimensional echocardiography. A light pen digitizing and computation system, controlled by a microprocessor, was used to outline the left atrium and ventricle in orthogonal apical views. Then, to calculate end-systolic and end-diastolic atrial and ventricular volumes, a modified Simpson's rule formula was used. End-systolic left atrial volume (mean +/- standard deviation) was 37 +/- 11.7 ml or 21 +/- 6.6 ml/m2. The change in left atrial volume from end-systole to end-diastole was 24 +/- 7.6 ml or 13.5 +/- 4.3 ml/m2, which represented 37 +/- 12.9% of left ventricular stroke volume. The mean fractional emptying of the left atrium was 65 +/- 8.9% and the conduit volume was 41 +/- 14.0 ml or 23 +/- 7.9 ml/m2. These values are similar to those reported in studies in which left atrial function was calculated from contrast angiography.
Adult↗