ASSESSMENT OF VASOACTIVE AGENTS AND VASCULAR AGING BY THE 2ND DERIVATIVE OF PHOTOPLETHYSMOGRAM WAVE-FORM

Citation
K. Takazawa et al., ASSESSMENT OF VASOACTIVE AGENTS AND VASCULAR AGING BY THE 2ND DERIVATIVE OF PHOTOPLETHYSMOGRAM WAVE-FORM, Hypertension, 32(2), 1998, pp. 365-370
Citations number
16
Categorie Soggetti
Peripheal Vascular Diseas
Journal title
ISSN journal
0194911X
Volume
32
Issue
2
Year of publication
1998
Pages
365 - 370
Database
ISI
SICI code
0194-911X(1998)32:2<365:AOVAAV>2.0.ZU;2-1
Abstract
To evaluate the clinical application of the second derivative of the f ingertip 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 fingert ip photoplethysmogram and its second derivative in 39 patients with a mean+/-SD age of 54+/-11 years. The augmentation index was defined as the ratio of the height of the late systolic peak to that of the early systolic peak 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 mu g angiotensin from 126/7 4 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 tha t of the a wave, decreased after angiotensin from -0.40+/-0.13 to -0.6 2+/-0.19 and increased after nitroglycerin to -0.25+/-0.12 (P<0.001 an d P<0.001, respectively). The negative d/a increased with increases in plethysmographic and ascending aortic augmentation indices (r=0.79, P <0.001, and r=0.80, P<0.001, 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 age nts. In study 2, the second derivative of the plethysmogram waveform w as measured in a total of 600 subjects (50 men and 50 women in each de cade 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) (r =0.80, P<0.001, y=0.023x-1.515), The second derivative aging index was higher in 126 subjects with any history of diabetes mellitus, hyperte nsion, hypercholesterolemia, and ischemic heart disease than in age-ma tched subjects without such a history (-0.06+/-0.36 versus -0.22+/-0.4 1, P<0.01). Women had a higher aging index than men (P<0.01). The b-c- d-e/a ratio may be useful for evaluation of vascular aging and for scr eening of arteriosclerotic disease.