Progress in lipid reporting practices and reliability of blood cholesterol measurement in clinical laboratories in Nebraska. Efforts to align results with the Centers for Disease Control, and feasibility of meeting National Cholesterol Education Program Guidelines.

The National Cholesterol Education Program has recommended that all laboratories be consistent, precise, and accurate in the reporting and measurement of blood cholesterol levels. In a follow-up to a 1984 survey study, we assessed the changes in reporting procedures for measurements of blood lipid levels in 16 clinical laboratories in Nebraska. Using human serum reference materials of known cholesterol concentrations provided by the Centers for Disease Control, we also assessed the precision and accuracy of measurement of blood cholesterol levels in clinical laboratories in Nebraska. Fourteen of the 16 laboratories restudied in 1987 had altered the reference range for total serum cholesterol since 1984, 86% of whom lowered the upper limit of the reference range. Eleven of 16 laboratories expressed reference ranges for total serum cholesterol in terms of patient age in 1987, while only 7 of 20 did in 1984. Gender-based reference ranges increased from 0 to 5 from 1984 to 1987. Similar trends were seen in the reporting of high-density lipoprotein cholesterol and triglyceride concentrations. Reporting procedures varied greatly; only 1 laboratory used National Cholesterol Education Program risk levels for measuring total serum cholesterol levels. Fifteen laboratories met the National Cholesterol Education Program recommendation for precision (coefficient of variation, less than or equal to 5%) and 78% of laboratories obtained results that satisfied the current recommendation for accuracy (within 5% of "true value," as determined by the Centers for Disease Control).

Sigmoidity of the ventricular septum revisited: progression in early adulthood, predominance in men, and independence from cardiac mass.

Meager quantitative anatomic information is available regarding the orientation of the left ventricular outflow tract (LVOT) relative to the ventricular septum (VS), or the relation of these variables to patient age, sex, or other cardiac features. We studied 57 formaldehyde-fixed adult human heart specimens at autopsy from 29 men and 28 women ranging in age from 20 to 91 years (mean age = 66 years). Blinded measurement of 10 morphologic parameters, repeated on 2 occasions, included anatomic indexes of VS sigmoidity (angle between the aortic and the mitral plane). While sigmoidity was not correlated with patient height, body weight, body mass index, cardiac mass (or presence of systemic hypertension), cause of death, or VS length, it was significantly (p less than 0.05) progressive through age groups 20-39 years, 40-59, 60-79 and greater than or equal to 80. The overall correlation of aortic-mitral plane angle (A-MPA) with age was +0.59 (P less than 0.0001), a relationship also noted within each age group. The mean A-MPA increased from 118 degrees to 127, 131 and 134 considering all specimens. Men had consistently greater sigmoidity than women. The steady increase in sigmoidity of the ventricular septum from early adulthood may alter clinical conclusions about pathologic conditions which are based on septal curvature or prominence.