Pulse pressure (PP) is a complicated physiological index influenced by various factors including arterial stiffness and stroke volume (SV). Especially, PP is largely determined by SV in young people who show high PP amplification, leading to a substantial discrepancy between peripheral and central PP. Central PP is assumed to be directly influenced by left ventricular ejection. The purpose of this study was to assess differences in the contribution of SV to central and peripheral PP.Design and Method:
This study included 44 patients in young group (≤50 years, 23 males) and 82 patients in older group (>50 years, 34 males). The SV was calculated by Doppler TTE. Brachial, aortic PP and pulse wave velocity (PWV) were measured using a brachial cuff-based oscillometric device (Mobil-O-Graph). The contributions of SV and other possible factors to each PP were tested using univariate and multivariate analyses.Results:
The SV significantly and positively correlated with both brachial (r = 0.58, p < 0.001) and aortic PP (r = 0.72, p < 0.001) in young, but not older, patients. The correlation coefficient for the SV in young patients against aortic PP was significantly greater than that against brachial PP (z = 2.03, p = 0.049). PWV significantly and positively correlated with both brachial (r = 0.63, p < 0.001) and aortic (r = 0.62, p < 0.001) PP in older, but not young, patients. After forward stepwise multiple regression analysis, only SV independently correlated with brachial PP (R2 = 0.34), while SV, heart rate and BSA independently correlated with aortic PP (total R2 = 0.69), in young patients. In older patients, PWV, gender, heart rate, and mean blood pressure, but not SV, independently correlated with brachial (total R2 = 0.59) and aortic PP (total R2 = 0.58).Conclusions:
In young patients, SV was a stronger determinant of aortic PP than brachial PP. On the other hand, SV did not have a significant influence to brachial or aortic PP in older subjects.