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Biomedical subjects

B Lake

Publications and source records attributed to B Lake.

At least 37 records · Page 2Linked to original sources
PubMed1977

Blood viscosity factors in evaluation of submaximal work output and cardiac activity in men.

Sixty-two male subjects, including patients with postmyocardial infarction, angina, other disorders, and normals, were studied by exercise testing on the bicycle ergometer, including exercise ECG, and by in vitro determination of blood viscosity, plasma viscosity, aggregation of red cells, and other factors. Significant correlations were found between the blood viscosity factors on the one hand, and different terms describing physical fitness and cardiac functions on the other. In all correlations an elevation of blood viscosity factors led to lower fitness or lower cardiac efficiency; and a decrease of blood viscosity (or plasma viscosity, or compound viscosity product) was associated with better fitness and higher cardiac efficiency. Similarly, ECG ST-segment depression was proportional to increase of blood viscosity factors. All these highly significant correlations were found within a very narrow range of hematocrits, while the hematocrit value itself was not significant in this study.

Adult↗
PubMed1976

Definition of an exercise tolerance test.

Three hundred subjects undertook a submaximal bicycle ergometry procedure which was terminated at level 19 on the Borg perceived exertion rating scale. The findings indicated that the total work output was an effective reference criterion for each individual. Age and height were considerably more dominant than weight in affecting this output in both sexes. In women, however, the use of the maximum work load/maximum systolic blood pressure ratio gave the best explanation of variation. A numerical relative fitness ranking derived from the work output was developed to achieve comparison among subjects irrespective of age, height, weight and sex. This categorization revealed, interalia, that the average maximum systolic blood pressure was a major limiting factor in performance. Significant changes characteristic of ischaemia occurred in the electrocardiograms of a substantial proportion of subjects, including the apparently well, the proportion being higher in women than in men. There were definite differences between the ranked work load categories. The relative fitness ranking is of value in assessing a variety of factors affecting performance in heterogeneous populations, and also in following population responses to various procedures.

Adolescent↗
PubMed1976

Exercise fitness, cardiac work and blood viscosity factors in patients and normals.

A study of 41 cardiovascular patients and normals showed significant correlations between physical fitness (as expressed by a fitness index based on work output) and high shear rate blood viscosity (p less than 0.01); between the cardiac work expressed as double product (= myocardial oxygen demand) and aggregation of red cells (p less than 0.05); between the triple term of cardiac work (fitness index divided by double product) and high shear rate blood viscosity (p less than 0.005) or aggregation of red cells (p less than 0.05), in all cases correlations being negative i.e., higher cardiac work or higher fitness being related to low blood viscosity or lower aggregation of red cells. Significant differences were found between high-fitness and low-fitness groups, the high-fitness group showing from plasma viscosity (p less than 0.0005), lower fibrinogen level (p less than 0.05), and higher albumin/fibrinogen ratio (p less than 0.01).

Adult↗