What question did this study set out to answer?

To study the changes in flow and heart contractility during induced coronary insufficiency in dogs.

July 1, 1968Circulation ResearchOpen Access

Flow in the Major Branches of the Left Coronary Artery during Experimental Coronary Insufficiency in the Unanesthetized Dog

Q: What is the clinical evidence from this study?

Study design: Other. Population: Experimental coronary insufficiency. Intervention: Gradual constriction of the left circumflex coronary artery branch vs. Unimpeded descending coronary artery branch / baseline control. Primary outcome: Flow in the left circumflex and descending branches of the coronary artery, and cardiac contractility index.

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Key result

Gradual constriction of the left circumflex coronary artery decreased reactive hyperemia and contractility, followed by increased flow in the unimpeded descending branch within 24 hours.

Population

Unanesthetized dogs with experimentally induced coronary insufficiency

Comparison

Gradual constriction of the left circumflex… vs Baseline state before partial reduction of flow…

Design

Preclinical

Follow-up

up to 24 hours

Authors

EKEDWARD M. KHOURIWalter Reed Army Institute of Research DGDonald E. GreggWalter Reed Army Institute of Research HLH. S. LowensohnLöwenstein Medical (Germany)

Discussion

Member takes

Implication

Supports rapid collateral recruitment in experimental coronary constriction; leaves open translation to human coronary disease.

Key Points

To study the changes in flow and heart contractility during induced coronary insufficiency in dogs.
Flow measurements conducted in left circumflex and descending branches of coronary artery, and ascending aorta.
Pressure recorded in ascending aorta and left ventricle during experimental occlusion.
Drug responses to isoproterenol, nitroglycerin, and dipyridamole evaluated pre- and post-occlusion.
Reactive hyperemia decreased as left circumflex artery constriction increased.
Peak flow rates in the descending branch increased after a 10-second occlusion post-occlusion.
Response to drugs was diminished in the occluded vessel but improved progressively in the unaffected descending artery.

Structured PICO

Population

Unanesthetized dogs with experimentally induced coronary insufficiency

Intervention

Gradual constriction of the left circumflex coronary artery branch, and administration of isoproterenol, nitroglycerin, and dipyridamole

Comparator

Baseline state before partial reduction of flow, and the unimpeded descending coronary artery branch

Outcome

Coronary flow in the left circumflex and descending branches, aortic flow, aortic and left ventricular pressures, and cardiac contractility indexsurrogate

Experimental coronary insufficiency in dogs leads to compensatory increases in flow in unimpeded coronary branches, consistent with the rapid development of collateral circulation.

Cite This Study

KHOURI et al. (1968) studied Experimental coronary insufficiency. Gradual constriction of the left circumflex coronary artery branch vs. Unimpeded descending coronary artery branch / baseline control was evaluated on Flow in the left circumflex and descending branches of the coronary artery, and cardiac contractility index. Gradual constriction of the left circumflex coronary artery decreased reactive hyperemia and contractility, followed by increased flow in the unimpeded descending branch within 24 hours.

synapsesocial.com/papers/6a0d642748a82a5ce309b6d6 https://doi.org/10.1161/01.res.23.1.99

Topics

Coronary CT angiography

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Flow in the Major Branches of the Left Coronary Artery during Experimental Coronary Insufficiency in the Unanesthetized Dog

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Topics

Flow in the Major Branches of the Left Coronary Artery during Experimental Coronary Insufficiency in the Unanesthetized Dog

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Topics

Also Consider