iBet uBet web content aggregator. Adding the entire web to your favor.
iBet uBet web content aggregator. Adding the entire web to your favor.



Link to original content: https://www.ncbi.nlm.nih.gov/pubmed/9317783
THE INTRINSIC PROPERTIES OF AN IN SITU PERFUSED CROCODILE HEART - PubMed Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1994 Jan;186(1):269-88.
doi: 10.1242/jeb.186.1.269.

THE INTRINSIC PROPERTIES OF AN IN SITU PERFUSED CROCODILE HEART

C Franklin, M Axelsson

THE INTRINSIC PROPERTIES OF AN IN SITU PERFUSED CROCODILE HEART

C Franklin et al. J Exp Biol. 1994 Jan.

Abstract

An in situ perfused crocodile (Crocodylus porosus) heart preparation was developed to investigate the effects of input and output pressure on cardiac dynamics and to determine the conditions that lead to a right-to-left cardiac shunt. The pericardium was kept intact, both the left and right atria were perfused and all three outflow tracts (right aortic, left aortic and pulmonary) were cannulated, enabling pressures and flows to be monitored. The perfused heart preparation had an intrinsic heart rate of 34 beats min-1 and generated a physiological power output. Both the left and right sides of the heart were sensitive to filling pressure. Increasing the filling pressure to both atria resulted in an increase in stroke volume and cardiac output (Frank­Starling effect). Increasing the filling pressure to the right atrium also had a positive chronotropic effect. Large right ventricular stroke volumes initiated a right-to-left shunt, despite the left aorta having a pressure 1.5 kPa higher than the pulmonary output pressure. The left ventricle was able to maintain its output and stroke volume up to an output pressure of approximately 8 kPa. However, the right ventricle was significantly weaker. Right ventricular output and stroke volume showed a marked decrease when the output pressure was increased above 5 kPa. A right-to-left shunt occurred when pulmonary output pressure was increased. Surprisingly, a shunt occurred into the left aorta before the pressure in the pulmonary artery became greater than that in the left aorta. Once the pressure in the pulmonary artery exceeded the left aortic pressure, pulmonary artery flow ceased and right ventricular output was solely via the left aorta. A right-to-left shunt could also be initiated by increasing the filling pressure to the left atrium.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

LinkOut - more resources