Arterial hemodynamics in human hypertension

• Published in: The Journal of clinical investigation Vol. 78; no. 6; pp. 1462 - 1471
• Main Authors: TING, C. T, BRIN, K. P, LIN, S. J, CHANG, M. S, CHIANG, B. N, YIN, F. C. P
• Format: Journal Article
• Language: English
• Published: Ann Arbor, MI American Society for Clinical Investigation 01.12.1986
• Subjects: Adult; Age Factors; Aorta - physiopathology; Arterial hypertension. Arterial hypotension; Arteries - physiopathology; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Clinical manifestations. Epidemiology. Investigative techniques. Etiology; Electric Conductivity; Female; Hemodynamics - drug effects; Humans; Hypertension - physiopathology; Male; Medical sciences; Middle Aged; Nitroprusside - pharmacology; Physical Exertion; Propranolol - pharmacology; Hypertension; Hemodynamics; Essential; Artery
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI112737

Differences in aortic impedance between normotensives and hypertensives are not well characterized. We examined impedance in 8 normotensive and 11 hypertensive (mean 96.7 vs. 122.2 mmHg) age-matched, Chinese patients undergoing cardiac catheterization at rest, during nitroprusside, and handgrip exercise before and after beta blockade (propranolol). Hypertensives had higher resistance (2,295 vs. 1713 dyn-s/cm5), characteristic impedance (145.7 vs. 93.9 dyn-s/cm5), total external power (1,579 vs. 1174 mW), peripheral reflections (ratio of backward to forward wave components of 0.54 vs. 0.44), and first zero crossing of impedance phase angle (4.15 vs. 2.97 Hz). These abnormalities were eliminated with vasodilatation. Differences between groups were not further exacerbated when pressure was increased during handgrip exercise. Beta blockade further increased resistance and reflections. Thus, hemodynamic abnormalities of essential hypertension (increased resistance, reflections, and pulse wave velocity, and decreased compliance) are compatible with an increased vasomotor tone that is further unmasked during generalized beta blockade.