Cardiovascular Function Analysis of Untreated Hypertensive and Normotensive Participants in Cardiopulmonary Exercise Test

Yahui Zhang1, Zhihao Jiang1, Lin Qi1, Lisheng Xu1, Xingguo Sun2, Xinmei Chu3, Yanling Liu4, Stephen E Greenwald5
1Northeastern university, 2Fuwai Hospital, National Center for Cardiovascular Disease, 3Beijing Haidian Hospital, Peking University Third Hospital Haidian Campus, 4Beijing Rehabilitation Hospital of Capital Medical University, 5Blizard Institute, Barts & The London School of Medicine &Dentistry, Queen Mary University of London


Abstract

Pulse wave analysis is a simple, low cost and non-invasive method for obtaining important information related to the cardiovascular system. This study aimed to investigate and compare the cardiovascular function between untreated hypertensive and normotensive participants before, during and after cardiopulmonary exercise test (CPET). Thirty participants (15 untreated hypertension and 15 normotension) were enrolled. Photoplethysmography (PPG), respiration signal and ECG were simultaneously collected while participants were conducting CPET. The second derivative of PPG (b/a, c/a, d/a, e/a and (b-c-d-e/a)), respiratory rate extracted by power spectrum analysis, pulse transit time (PTT) were analyzed. The results demonstrated that there were significant differences in e/a, respiratory rate, and PTT between two groups, while there were no significant differences in b/a and (b-c-d-e)/a before CPET. By contrast, the b/a, (b-c-d-e)/a and respiratory rate were significant higher after CPET. The c/a and d/a were significant lower in untreated hypertensive participants than those in normative participants after CPET. In addition, only respiratory rate was significant higher in untreated hypertensive participants than that in normative participants during CPET. The differences of vascular function and respiratory activity are found after CPET between untreated hypertension participants and controls. Additionally, we also found that there were significant differences in respiratory activity and the autonomic nervous function between two groups during CPET.