Comparisons of direct and indirect blood pressure with pressure-flow dynamics during exercise.

Abstract

Two healthy men, 40 and 57 years of age, underwent right-sided cardiac catheterization and retrograde supra-aortic catheterization to compare direct intra-aortic blood pressures with those recorded simultaneously by auscultation of the brachial artery and to study the pattern of pressure and flow dynamics during work at moderate, strenuous, and maximal intensities. In most instances systolic pressures measured by auscultation were in close agreement with the directly recorded measurements. The indirectly measured diastolic pressures were consistently higher than the directly recorded values in one subject and they were consistently lower than the directly measured diastolic pressures for the other subject. Neither the muffling nor the cessation of sound could be closely identified with minimal intra-aortic pressures. Systolic and mean pressures, minute flow, stroke volume, and atrio-ventricular (A-V) O2 difference increased with greater work intensities.