Related Experiment Video
Updated: Oct 15, 2026

Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
Published on: August 17, 2022
[Mechanism of coronary vasodilation in myocardial regional hypoxia]
1Department of Circulation, First Clinical College, China Medical University, Shenyang.
Objective:
To determine if coronary vasodilation is dependent upon adrenergic activation during myocardial regional.
Methods:
Studies were conducted in 10 Mongrel dogs of either sexes, in which LAD was perfused with normoxic (CAO2 = 18.4-20.4 ml/100 ml) or regional hypoxic (CAO2 = 7.8-8.1 ml/100 ml) blood with coronary perfusion system by self-control methods.
Results:
No significant differences were observed in hemodynamic values with regional hypoxia compared with normoxia before adrenergic receptor blocker was given, but coronary blood flow increased by 225%. There were significant differences in dp/dt max, dp/dt min after adrenergic blocker was given. Whether there was regional hypoxia or not, coronary blood flow still increased by 190%.
Conclusion:
Coronary vasodilation is independent upon adrenergic activation during myocardial regional hypoxia.
Related Concept Videos
Hypoxia
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Pathophysiology of Cardiac Performance
Angina I: Introduction
Nitric Oxide Signaling Pathway
Coronary Artery Disease II: Pathophysiology
Antianginal Drugs: Nitrates and β-Blockers
Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow. Administered...

