No abstract

A three-dimensional echocardiographic system has been developed that can accurately compute left ventricular mass in vitro. This study was designed to validate the new echocardiographic system for the measurement of left ventricular mass in vivo and to compare the accuracy of three-dimensional echocardiography to the accuracy of conventional two-dimensional echocardiography for measuring left ventricular mass. Echocardiographic imaging was performed 6 h following coronary ligation in 20 open chest dogs, at which time the heart was excised and the left ventricle weighed. Three-dimensional echocardiography used multiple short axis sections and polyhedral surface reconstruction to compute myocardial volume. The two dimensional methods employed the truncated ellipsoid model and the area-length model. Myocardial volume was multiplied by 1.05 g/cc and echocardiographic mass estimates were compared to the true left ventricular weight. Three-dimensional echocardiography provided the best correlation (r = 0.96, upsilon r = 0.88 and r = 0.83 for the truncated-ellipsoid and area-length methods, respectively), and the lowest standard error of the estimate for the regression equation (+/- 5.5 g upsilon +/- 11.0 and +/- 14.6 g, respectively). Three dimensional echocardiography also had the lowest standard deviation for the echo-true mass differences (+/- 5.8 g upsilon +/- 10.7 g and +/- 14.2 g) and a lower root mean square percent error (6.8%) upsilon 12.6% and 12.7%). In this open chest canine model, three-dimensional echocardiography is more accurate than standard two-dimensional echocardiographic methods for measuring left ventricular mass.

Obesity is a known risk factor for developing cardiovascular disease, including heart failure. However, the impact of obesity on patients with heart failure is unclear. Weight reduction is a recommended method of prevention of cardiovascular disease. However, the phenomenon of the "obesity paradox" (or "reverse epidemiology") revealed that overweight and mild to moderate obesity are associated with better outcomes in patients with heart failure compared with patients at normal or ideal weight. Even more, increases of weight in cachectic heart failure patients might improve survival, although patients with heart failure who are overweight or mildly to moderately obese have better outcomes than patients with heart failure who are at ideal or normal weight. In heart failure patients, weight reduction through diet regulation, moderate exercise, and bariatric surgery can improve quality of life and New York Heart Association functional class, but it is yet unclear if these measures will improve survival.

Three-dimensional echocardiography is a more accurate means of noninvasively estimating myocardial infarct size in this canine model than two-dimensional echocardiography.

. (1968). Eflects of Maternal Essential Fatty-acid Deficiency o n Neonatal Rat Brain. DEVELOPMENTAL PSYCHOBIOLOGY, l(4) 225-229. Female weanling rats were raised to sexual maturity on either a normal stock diet or an essential fatty-acid (EFA) deficient diet, and then bred. Brain weight and lipid composition of the offspring from these animals were measured as part of an investigation into factors contributing to the early death of EFA-deficient progen). Lactation failure does not seem to be an adequate explanation of the early deaths since the dead EFA-dehcient offspring frequently have milk in their stomachs. Maternal behavior including nesting was lacking, however, in EFA-deficient dams. The EF4-deficient brains weighed less than normal neonatal brains, and frequently had subdural hemorrhaging. Relative to body weight, however, some "sparing" of the brain was apparent. Total hi aiii sterol concentration was not measurably different, but fatty-acid composition of total brain lipid and phospholipid was. T h e EFA-deficient offspring had relatively less arachidonate and other EFA-related fatty acids, while the proportion of ti ienoic acids, principallr 20:3 and 2 2 3 was increased considerably. In phosphatidyl ethanolarnine, the proportion of 16:O was particularly elevated in the EFA-deficient brains. T h e results are discussed in relation to the integrity of inyelin and the synthesis of prostaglandins, as possible factors in the premature death of EFA-deficient progeny.essential fatty acid deficiency brain myelin maternal behavior lipid and phospholipid multiple sclerosis prostaglandins HE PARTICULARLY high rate of fetal and early post-