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C Hoeven

Publications and source records attributed to C Hoeven.

4 recordsLinked to original sources

"Sensitive tests" are poor predictors of the decline in forced expiratory volume in one second in middle-aged smokers.

In 1978, we studied 3 groups of steelworkers 45 to 55 yr of age who were all smokers: "obstructive" smokers (OS) with a FEV1/VC less than 66.6% (59.8% in average) (n = 37), smokers with "small airways disease" (SAD) and an abnormal closing capacity and/or slope of phase III (delta N2) but normal FEV1/VC (n = 32), and "resistant" smokers (RS) with normal functional indices (n = 36). Smokers with SAD had a lower (p less than 0.05) FEV1/VC (71.7%) than did RS (74.9%). We studied again 6 yr later about 85% of survivors in each group. Analysis of variance showed that FEV1 decreased significantly (p less than 0.001) only in OS (from 2.67 to 2.46 L). In RS and smokers with SAD, FEV1 declined from 3.34 to 3.26 L and from 2.95 to 2.85 L, respectively (p greater than 0.05). In all 3 groups, delta N2 increased (p less than 0.001) from 0.77 to 1.30% N2/L in RS, 1.41 to 2.43% N2/L in smokers with SAD, and 2.22 to 4.20% N2/L in OS. A multivariate analysis showed that the initial N2 explained about 30% (p less than 0.001) of the decline in FEV1 in OS, but only 10% (p less than 0.001) in the 3 groups together. In fact, the link between delta N2 and fall in FEV1 was restricted to OS. Closing volume and maximal expiratory flow rates were not related to decline in FEV1. The link between uneveness of ventilation and subsequent loss of FEV1 is of physiopathologic interest.(ABSTRACT TRUNCATED AT 250 WORDS)

Forced Expiratory Volume↗

The normal pediatric Frank orthogonal electrocardiogram: variations according to age and sex.

Quantitative computerized analysis of QRS and ST-T parameters of the Frank orthogonal electrocardiogram and vectorcardiogram was undertaken in a large series of 1317 normal infants, children and adolescents stratified according to age and sex. This study confirms the influence of these two constitutional variables, age and sex, over the normal VCG in the whole time span between birth and late adolescence. As children mature, the mid-portion of the spatial QRS loop shifts leftward and posteriorly with relatively little change in the initial and terminal vectors. The spatial T loop shifts anteriorly but at a different rate in males and in females. Unidirectional changes in many amplitude parameters are observed until age 19 in males whereas in females these changes stop earlier or even show a reverse trend around puberty, leading to more important differences between adolescent males and females. Sex-related differences are the most marked for parameters representing the repolarization process. Infants under six months of age form a distinct group with larger dispersions and more disparate variations in the values of vectorcardiographic parameters than in older children. In the newborn period larger sample size might be necessary in order to reduce the normal ranges of vectorcardiographic parameters.

Adolescent↗

The normal pediatric Frank orthogonal electrocardiogram: influence of weight, height and chest circumference.

The influence of body weight, height and chest circumference on the pediatric Frank vectorcardiogram (VCG) was investigated in a population of 1317 normal infants, children and adolescents. Simple linear regression analysis showed that 94, 96 and 57 VCG variables were significantly correlated with weight, height and chest circumference, respectively. These numbers were reduced to 10, 18 and 6 VCG variables after a stepwise multiple correlation analysis. The relationship between the VCG and the somatic variables was also studied in ten different age/sex subgroups. Simple regression analysis showed a residual significant correlation between the VCG and all three somatic variables in each group. The multiple correlation analysis allowed us to define a minimum set of VCG variables, from one to six, which could explain all the variation produced by the somatic variables. The coefficient of multiple correlation between VCG and weight was the highest in babies 0 to 6 months old (R = 0.73). For height, the strongest correlation was found in females two to five years old (R = 0.76). In subjects older than two years of age, the correlation between chest circumference and VCG (R = 0.30 to 0.69) was weaker than between VCG and pediatric VCG after stratification for age and sex, especially in the youngest groups.

Adolescent↗