Cardiac output and blood pressure at rest and during exercise in boys with bronchial asthma.

Cardiac output, using dye-dilution technique, and intra-arterial blood pressure at rest and during exercise on a bicycle ergometer were determined in six boys with bronchial asthma, mean age 11.9 years. Intra-arterial blood pressure was also measured in another group of eight boys with bronchial asthma. Cardiac output, stroke volume, arteriovenous oxygen difference, blood pressure and total peripheral vascular resistance at rest and during exercise up to maximal level were within the normal limits of healthy boys of the same age. At maximal exercise, cardiac output averaged 12.4 l/min, stroke volume 66 ml, systolic, diastolic and mean blood pressures 128, 81 and 107 mmHg, respectively, and total peripheral vascular resistance 10.9 mmHg/l/min. The maximal arteriovenous oxygen difference amounted to 14.1 ml/100 ml blood which is similar to that in healthy adults.