Related Experiment Video
Updated: May 30, 2026
09:55
Tissue Engineering by Intrinsic Vascularization in an In Vivo Tissue Engineering Chamber
Published on: May 30, 2016
No-reflow phenomenon: maintaining vascular integrity
1Heart Institute, Good Samaritan Hospital, Keck School of Medicine, University of Southern California, Los Angeles, CA 90017, USA. rkloner@goodsam.org
Journal of Cardiovascular Pharmacology and Therapeutics
|August 9, 2011
Summary
The no-reflow phenomenon, characterized by microvascular obstruction, hinders myocardial reperfusion after heart attacks. Identifying and treating this condition can improve healing, reduce heart damage, and enhance survival rates.
Area of Science:
- Cardiology
- Vascular Biology
- Pathophysiology
Background:
- The no-reflow phenomenon describes impaired blood flow to the heart muscle after coronary artery occlusion, despite successful opening of the main artery.
- This condition involves microvascular obstruction, potentially exacerbated by reperfusion injury and emboli during interventions.
Purpose of the Study:
- To review the mechanisms, clinical manifestations, and prognostic implications of the no-reflow phenomenon in myocardial infarction.
- To highlight the need for effective therapeutic strategies to address no-reflow.
Main Methods:
- Review of experimental and clinical studies investigating the no-reflow phenomenon.
- Analysis of diagnostic methods including imaging (MRI, echo contrast) and flow markers (TIMI scores, myocardial blush grade).
Main Results:
- No-reflow is associated with microvascular endothelial swelling, emboli, and reperfusion injury, leading to expanded infarcts in animal models.
- In humans, no-reflow predicts adverse outcomes like left ventricular remodeling, heart failure, shock, and reduced survival, independent of infarct size.
Conclusions:
- No-reflow is a critical determinant of poor prognosis after myocardial infarction.
- Therapeutic interventions targeting no-reflow may improve myocardial healing and patient outcomes, reducing long-term mortality.
Related Concept Videos
01:16Vascular Spasm
The vascular phase, also known as vasospasm, is the initial stage of hemostasis, crucial for preventing excessive bleeding when a blood vessel is injured. After a vessel is cut, nerves in the damaged area trigger pain and other sensory impulses. Simultaneously, the smooth muscles in the vessel wall contract, resulting in a vascular spasm. This contraction reduces the vessel's diameter at the injury site, slowing or stopping blood loss through the vessel wall. Vascular spasms typically last for...
01:17Autoregulation of Blood Flow
Autoregulation mechanisms are characterized by their inherent capacity for self-regulation without necessitating specific nervous stimulation or endocrine control. These mechanisms facilitate the adjustment of blood flow and, therefore, perfusion specific to each tissue region. This self-regulation encompasses chemical signals and myogenic controls.
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.
01:24Regulation of Angiogenesis and Blood Supply
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
01:16Clot Retraction and Fibrinolysis
After a fibrin clot is formed, the next step is clot retraction, a vital process facilitated by platelet contractile proteins, such as actin and myosin. These proteins pull the fibrin strands closer together and condense the clot. This action reduces the size of the clot, creating a smaller, denser structure that effectively seals off the damaged vessel. Clot retraction consolidates the clot and helps with wound healing by bringing the edges of the damaged blood vessel closer together.
01:04Venous Return
The circulatory system plays a crucial role in ensuring the optimal functioning of the human body. One of its critical components is venous return - the process that completes the blood circulation cycle. This article will delve into the concept of venous return, how it works, and its significance to our health.
What is Venous Return?
Venous return refers to the rate at which blood flows back to the heart from the body's peripheral veins. It's an integral part of the circulatory system as it...
What is Venous Return?
Venous return refers to the rate at which blood flows back to the heart from the body's peripheral veins. It's an integral part of the circulatory system as it...
01:15Ischemic Stroke ll: Pathophysiology
An ischemic stroke occurs when a cerebral blood vessel becomes obstructed, most often by a thrombus or embolus, interrupting the delivery of oxygen and glucose to brain tissue. Because neurons rely on continuous aerobic metabolism, energy failure begins within minutes of reduced perfusion. The region receiving the least blood flow becomes the infarct core, an area of irreversible cellular death. Surrounding this core lies the penumbra, a zone of hypoperfused but still viable tissue that is...