Circulation, Vol 56, 533-539, Copyright © 1977 by American Heart Association
Y Enson, JA Wood, NB Mantaras and RM Harvey
Increased resistance to blood flow stemming from structural and functional
abnormalities of the lungs may cause pressure in the pulmonary artery to
exceed that in the left ventricle at the end of ventricular diastole. This
study explores the possible contribution of heart rate to the diastolic
pressure gradient observed in the presence of acutely induced hypoxia.
Pulmonary hemodynamics were examined in mongrel dogs with chronic
atrioventricular dissociation with and without hypoxia at two different
heart rates and during sequential increments in heart rate while the
animals breathed room air. Studies during sequential pacing indicate that
heart rate was of greater importance than blood flow in determining the
magnitude of the gradient. Heart rate has to be considered when the causes
of pulmonary hypertension and the effects of drugs or other agents on the
pulmonary circulation are being investigated.
ARTICLES
The influence of heart rate on pulmonary arterial-left ventricular pressure relationships at end-diastole
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1977 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |