Total arterial compliance is a major determinant of peak oxygen uptake

Total arterial compliance (TAC, defined as dV/dP) is a major component of the arterial system. A decreased TAC increases left ventricular load and has a detrimental effect on coronary perfusion. We sought to assess the influence of TAC on the functional reserve (VO₂max). Fourteen patients (mean age 64±14y) with known or suspected coronary artery disease and eleven controls (34±5y) underwent supine bicycle exercise echocardiography. Audio Doppler signal output of the echocardiographic machine was digitized with a customized hardware and software interface simultaneously with carotid tonometry and ECG. TAC at rest was calculated by the pulse pressure method (PPM). By step-wise forward multivariate analysis, independent predictors of VO₂max were patient versus control status, peak exercise cardiac output and TAC. The described PC-based acquisition system for tonometry and Doppler signals permits the assessment of ventricular function and arterial biomechanics.