Assessment of Vasoactive Agents and Vascular Aging by the Second Derivative of Photoplethysmogram Waveform
K. Takazawa, N. Tanaka, M. Fujita, O. Matsuoka, T. Saiki, M. Aikawa, S. Tamura, C. Ibukiyama
1998
Hypertension
To evaluate the clinical application of the second derivative of the fingertip photoplethysmogram waveform, we performed drug administration studies (study 1) and epidemiological studies (study 2). In study 1, ascending aortic pressure was recorded simultaneously with the fingertip photoplethysmogram and its second derivative in 39 patients with a meanϮSD age of 54Ϯ11 years. The augmentation index was defined as the ratio of the height of the late systolic peak to that of the early systolic
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... in the pulse. The second derivative consists of an a, b, c, and d wave in systole and an e wave in diastole. Ascending aortic pressure increased after injection of 2.5 g angiotensin from 126/74 to 160/91 mm Hg and decreased after 0.3 mg sublingual nitroglycerin to 111/73 mm Hg. The d/a, the ratio of the height of the d wave to that of the a wave, decreased after angiotensin from Ϫ0.40Ϯ0.13 to Ϫ0.62Ϯ0.19 and increased after nitroglycerin to Ϫ0.25Ϯ0.12 (PϽ0.001 and PϽ0.001, respectively). The negative d/a increased with increases in plethysmographic and ascending aortic augmentation indices (rϭ0.79, PϽ0.001, and rϭ0.80, PϽ0.001, respectively). The negative d/a reflects the late systolic pressure augmentation in the ascending aorta and may be useful for noninvasive evaluation of the effects of vasoactive agents. In study 2, the second derivative of the plethysmogram waveform was measured in a total of 600 subjects (50 men and 50 women in each decade from the 3rd to the 8th) in our health assessment center. The b/a ratio increased with age, and c/a, d/a, and e/a ratios decreased with age. Thus, the second derivative aging index was defined as b-c-d-e/a. The second derivative wave aging index (y) increased with age (x) (rϭ0.80, PϽ0.001, yϭ0.023xϪ1.515). The second derivative aging index was higher in 126 subjects with any history of diabetes mellitus, hypertension, hypercholesterolemia, and ischemic heart disease than in age-matched subjects without such a history (Ϫ0.06Ϯ0.36 versus Ϫ0.22Ϯ0.41, PϽ0.01). Women had a higher aging index than men (PϽ0.01). The b-c-d-e/a ratio may be useful for evaluation of vascular aging and for screening of arteriosclerotic disease. (Hypertension. 1998;32:365-370.) Key Words: photoplethysmography Ⅲ second derivative wave Ⅲ augmentation index Ⅲ vasoactive agents Ⅲ vascular aging Ⅲ angiotensin Ⅲ nitroglycerin
doi:10.1161/01.hyp.32.2.365
pmid:9719069
fatcat:s7k4nqly3ze53h2kreiswdl62m