Initial evaluation of heart murmurs: are laboratory tests necessary?

Heart murmurs, most of them innocent, are the most common reason for referrals to a pediatric cardiologist. In the evaluation of murmurs, the electrocardiogram and echocardiogram are often included. The purpose of this study was to determine the utility of these examinations in the initial assessment of heart murmurs in children and adolescents. In a prospective series of 161 patients, the clinical diagnosis of heart murmurs by a pediatric cardiologist was compared with that obtained after electrocardiogram and echocardiogram (two-dimensional, M-mode, Doppler, and color-Doppler). On the basis of the clinical diagnosis the patients were classified as having "innocent murmur," "pathologic murmur," or "possible pathologic murmur." A total of 161 patients (51% males), aged 1 month to 17 years (median 3.2 years), were studied. After electrocardiogram, no diagnosis was changed. After echocardiogram, the clinical diagnosis of innocent murmur in 109 patients changed in 2 to pathologic (small ventricular septal defect 1, small atrial septal defect 1); pathologic murmur in 46 changed to innocent in 3 and possible pathologic in 2; and possible pathologic in 6 changed to innocent in 3 and to pathologic in 2. The clinical examination by an experienced pediatric cardiologist is an accurate means of assessing newly referred patients with murmurs. The clinical examination had a sensitivity of 96%, specificity of 95%, positive predictive value of 88%, and negative predictive value of 98%. The electrocardiogram, unlikely to disclose any unsuspected heart disease, may assist in reaching the lesion-specific diagnosis when there is underlying pathology. Echocardiography, although diagnostic when heart disease is suspected, is unnecessary in pediatric patients with clinically diagnosed innocent heart murmurs.

The vitamin status of infants in a free living population.

In infancy an adequate intake of vitamins, either from natural sources or as supplements, is of the utmost importance. The vitamin status of 325 infants was studied with regard to their food intake, vitamin supplementation and health from birth to the third birthday. Only data on vitamins A, C, E and folic acid are presented here. The proportion of bottle-fed infants having a serum level of vitamin C less than 0.30 mg/dl was 4.0 times (P less than 0.002), and of vitamin E less than 0.35 mg/dl was 2.2 times (P less than 0.05) higher than that of breast-fed infants. The proportion of infants with folate level less than 6.0 ng/ml was identical in both groups. No infant was observed with a vitamin A serum level less than 40 mcg/dl. The daily food intake of vitamin C less than 80% of RNI was found n 40% of infants at 6 months, in 10% at 12, and in none at 18 months and afterwards. Vitamin A followed a similar trend. 95% of infants had vitamin E and 75% had folate intake less than 80% RNI. Obviously the mean serum levels of vitamins A and C were significantly higher in supplemented infants at 6, 12, 18 and 30 months than in those without supplements. Health indicators, measured by number of self-reported illness related symptoms, differed according to supplementation. These findings indicated that, even if optimal food intake could supply the recommended quantity of vitamins, the risk of marginal deficiency always remained higher in infants without supplementation.

Nutrient intake patterns and nutritional status with regard to relative weight in early infancy.

To examine whether or not obesity in later life is related to feeding practice in early infancy, daily nutrient intake was studied in relation to relative weight in a cohort of 170 healthy infants from birth to 3 yr of age. Dietary records were made monthly for the first 6 months and at 3-monthly intervals thereafter, always covering the week preceding anthropometric measurements. The frequency distribution of relative weight varied according to age and sex; the infants did not remain in the same relative weight group during the observed period. When comparing the relative weight at 6 and 36 months, the coefficients of correlation were rather weak for both sexes (r = 0.33 and 0.35). There were no significant differences in the history of breast-feeding according to relative weight. The mean energy intake per kg of body weight was always lower in infants with relative weight above 105% of expected weight and fats and carbohydrates were consumed less in the same group. There were no differences in protein intake according to relative weight, although this intake was always higher than the recommended nutrient intake. Daily intake of zinc was comparable in all weight groups. Results indicate that the infants with above-average relative weights did not consume greater quantities of principal nutrients. The results, therefore, do not support the hypothesis that implicates overfeeding in early infancy as a major cause of obesity in later life.

Biochemical indices of nutritional status in maternal, cord, and early neonatal blood.

The nutritional status of 556 infants born in good health was measured by selected biochemical parameters in maternal venous blood, in mixed arteriovenous cord blood at delivery, and in infant's capillary blood collected at 5 days. The determinations indicating nutritional status were: Hb, hematocrit, protein, cholesterol, triglycerides, vitamins A, C, E, and folic acid, iron, calcium and magnesium. In maternal venous blood, a significant number of women were found to be deficient; 3.4% had Hb below 9.5 g/dl; 6.1% had hematocrit less than 30%; 4.0% had total protein below 5.5 g/dl; 7.0% had vitamin C below 0.20 mg/dl; 3.0% were deficient in iron (less than 40 microgram/dl), 3.6% in folic acid (less than 2.0 ng/ml) and 5.2% in calcium (less than 7.5 mg/dl). Significant correlations were more frequent between maternal and cord blood than in other comparisons. An influence of parity and maternal age was more evident for vitamin C in cord blood than in maternal venous blood. Iron in maternal and cord blood decreased in relation to parity.

Hair chromium at delivery in relation to age and number of pregnancies.

To test the hypothesis that chromium deficiency may be cumulative with age and increasing parity, hair chromium levels were measured in 432 women at delivery. Although the levels in general were lower than those found in nonpregnant women there was no correlation between hair chromium level and age or number of pregnancies. Hair zinc levels were also measured to rule out zinc deficiency as a factor.

Food intake patterns of infants with high serum cholesterol level at six months.

In our longitudinal study on the influence of nutrition upon health during infancy we found in a cohort of 556 infants in good health, 6.4% of infants at six months with a total serum cholesterol level above 200 mg/100 ml. Because of the known importance of hypercholesterolemia for health we studied the role of the food intake patterns during the first six months in relation to the serum cholesterol. We analysed the 24 hours dietary recalls, the dietary habits and a set of biochemical determinations used for evaluation of nutritional status: 35 infants, 21 girls and 14 boys, were compared with a control group matched for sex and birth date. There were no differences in mean body weight and socio-demographic characteristics. Daily energy and protein intake was higher in the study group. Analysing milk consumption we found that the daily intake was always higher in the high cholesterol group. The solid foods were introduced earlier in the study group, i.e. for 46% of infants in the second week of life. The serum levels of vitamins A, C, and E, and of triglyceride were higher in the high cholesterol groups. At twelve months 33% of infants with the cholesterol level above 200 mg/100 ml we included in the studied group remain still with a high level. This tendency underlines the need of further research.

The measurement of volatile chromium in biological materials.

Chromium is an essential trace element in mammals since dietary chromium deficiency results in glucose intolerance due to decreased sensitivity to insulin. In humans, both adults and children with glucose intolerance have been improved by treatment with chromium. Furthermore, chromium deficiency has been implicated as a causative factor in hypercholesterolemia and atherosclerosis. However, little is known of the metabolism of chromium in humans, primarily because of analytical difficulties. The biologically active form of chromium is the "glucose tolerance factor" (GTF) which is a co-ordination complex of trivalent chromium with nicotinic acid and certain amino acids. At physiological pH, ionic chromium as a simple inorganic salt is insoluble in water, but trivalent chromium forms stable complexes with ascorbic acid, amino acids and other substances present in blood and tissue. Chromium is present in serum, bound to protein and also as dialysable or ultrafiltrable chromium (free chromium). The free chromium includes G.T.F. and other coordination complexes and represents the metabolically active form of the element; the ratio free/protein bound chromium in serum varies within the individual according to the diet and the metabolic state.