It's called the development of Coronary Collaterals.
When the heart's arteries become narrowed or blocked (usually due to coronary artery disease), the heart can sometimes develop its own "natural bypasses" through the growth of new blood vessels. These new vessels are called coronary collaterals. These collaterals can reroute blood flow around the blockages, providing oxygen and nutrients to the heart muscle.
Understanding Coronary Collaterals
- What are they? Coronary collaterals are small, pre-existing blood vessels that connect different parts of the coronary artery system. They are normally tiny and don't carry much blood.
- How do they develop? When a major coronary artery becomes blocked, the pressure changes and the lack of oxygen signal the existing collateral vessels to enlarge and create new pathways. This process is called arteriogenesis.
- Why are they important? These collateral vessels act as a natural bypass, providing an alternative route for blood to reach the heart muscle that would otherwise be deprived of oxygen due to the blockage. This can reduce the severity of angina (chest pain) and potentially protect against heart attacks.
- Are they always sufficient? While coronary collaterals are beneficial, they may not always be sufficient to completely compensate for a major blockage. The extent of collateral development varies among individuals and depends on factors like the severity and duration of the blockage, genetics, and lifestyle factors.
- Factors influencing Collateral Development:
- Exercise: Regular physical activity has been shown to promote the growth of coronary collaterals.
- Ischemia: Gradual narrowing of coronary arteries triggers collateral development.
- Genetics: Some individuals are genetically predisposed to better collateral development.
Benefits of Coronary Collaterals
- Reduced angina symptoms
- Smaller heart attack size (if a blockage occurs)
- Improved survival rates in some cases of coronary artery disease
Limitations
- Collaterals may not always provide enough blood flow.
- Development takes time; they may not protect during a sudden, complete blockage.
- Their effectiveness varies among individuals.
In summary, while coronary collaterals are a beneficial natural mechanism that can provide a form of bypass for blocked heart arteries, their development and effectiveness can vary. Medical intervention may still be necessary in many cases to ensure adequate blood flow to the heart.
