Rentrop classification of coronary collaterals
Rentrop classification of coronary collaterals
What is the Rentrop classification of coronary collaterals?
The Rentrop classification is an angiographic grading system used to describe the extent of coronary collateral circulation (natural bypass vessels that form to supply myocardium distal to an occlusion).
It is based on the degree of collateral vessel filling visualized during coronary angiography:
Rentrop Classification of Coronary Collaterals
- Grade 0 → No visible collateral vessels.
- Grade 1 → Collateral filling of side branches of the occluded artery without visualization of the epicardial segment.
- Grade 2 → Partial filling of the epicardial segment of the occluded artery by collateral vessels.
- Grade 3 → Complete filling of the epicardial segment of the occluded artery by collateral vessels.
📌 Clinical importance:
- Higher Rentrop grades (2–3) indicate well-developed collateral circulation, often associated with better myocardial viability and protection against ischemia during coronary occlusion.
- However, even with Rentrop grade 3 collaterals, flow reserve may be limited compared to a normal coronary artery.
Would you like me to also create a diagram/infographic of the Rentrop classification (Grade 0–3) for quick visual learning?
| Grade | Short Label | Angiographic Description |
|---|---|---|
| 0 | No collaterals | No visible collateral channels. |
| 1 | Side-branch filling only | Collateral filling of side branches of the occluded artery, without visualization of the epicardial segment. |
| 2 | Partial epicardial filling | Collateral vessels produce partial filling of the epicardial segment of the occluded artery. |
| 3 | Complete epicardial filling | Collateral vessels produce complete filling of the epicardial segment of the occluded artery. |
Tip: On small screens, swipe horizontally to view the full table. Standard Rentrop angiographic classification used in clinical and research cardiology.
1. What does Rentrop Grade 0 indicate?
Show Explanation
Rentrop Grade 0 = no visible collateral circulation.
2. Which grade describes collateral filling of side branches only, without epicardial filling?
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Grade 1 = filling of side branches only, not the epicardial vessel.
3. Which grade indicates partial filling of the epicardial artery?
Show Explanation
Grade 2 = partial filling of epicardial segment by collaterals.
4. Rentrop Grade 3 refers to?
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Grade 3 = complete filling of epicardial artery via collaterals.
5. Which Rentrop grade provides the best myocardial protection?
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Grade 3 collaterals provide maximal protection against ischemia.
6. In Rentrop classification, which grade represents no collateral channels seen on angiography?
Show Explanation
Grade 0 = complete absence of collateral vessels.
7. Which Rentrop grade is defined by collateral filling of side branches without main artery visualization?
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Grade 1 = collaterals visible in side branches only.
8. Partial but not complete filling of epicardial artery corresponds to?
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Grade 2 = partial filling of epicardial artery segment.
9. Which grade represents full collateral perfusion of the epicardial artery?
Show Explanation
Grade 3 = complete filling of epicardial artery segment.
10. Rentrop Grade 2 collaterals supply how much of the epicardial segment?
Show Explanation
Grade 2 collaterals = partial epicardial filling.
11. Rentrop Grade 1 indicates:
Show Explanation
Rentrop Grade 1: Collaterals fill side branches of the occluded artery, without epicardial filling.
12. Rentrop Grade 2 indicates:
Show Explanation
Rentrop Grade 2: Collaterals produce partial filling of the epicardial segment of the occluded artery.
13. Rentrop Grade 3 signifies:
Show Explanation
Rentrop Grade 3: Collaterals produce complete filling of the epicardial segment of the occluded artery.
14. Which Rentrop grade represents absence of collateral circulation?
Show Explanation
Rentrop Grade 0: No visible collateral vessels are present.
15. Partial filling of the epicardial segment is seen in:
Show Explanation
Partial epicardial filling corresponds to Rentrop Grade 2.
16. Complete filling of the epicardial segment by collaterals is classified as:
Show Explanation
Complete filling of the epicardial segment corresponds to Rentrop Grade 3.
17. Which Rentrop grade corresponds to “no visible collateral channels”?
Show Explanation
Rentrop Grade 0 corresponds to no visible collateral channels.
18. Side branch filling without epicardial filling is seen in:
Show Explanation
Rentrop Grade 1 corresponds to side branch filling only, without epicardial filling.
19. Which Rentrop grade offers the greatest protection against ischemia?
Show Explanation
Rentrop Grade 3, with complete epicardial filling, provides the best protection against ischemia.
20. Rentrop Grade 2 collaterals are best described as:
Show Explanation
Rentrop Grade 2: Partial filling of the epicardial segment by collateral vessels.
Short Questions & Answers – Rentrop Classification of Coronary Collaterals
| Question | Answer |
|---|---|
| What is the Rentrop classification used for? | It is used to grade coronary collateral circulation on angiography. |
| How many grades are in Rentrop classification? | Four grades: 0, 1, 2, and 3. |
| What does Grade 0 indicate? | No visible collateral vessels. |
| What does Grade 1 indicate? | Collateral filling of side branches only, no epicardial filling. |
| What does Grade 2 indicate? | Partial filling of the epicardial segment of the occluded artery. |
| What does Grade 3 indicate? | Complete filling of the epicardial segment of the occluded artery. |
| Which grade represents well-developed collaterals? | Grades 2 and 3. |
| Which grade indicates the absence of collateral circulation? | Grade 0. |
| What is the clinical significance of Rentrop Grade 3? | It suggests complete collateral supply to the distal artery, providing better myocardial protection. |
| Does Rentrop classification assess functional flow reserve? | No, it only shows angiographic filling, not physiological flow capacity. |
20 Important Facts – Rentrop Classification of Coronary Collaterals
| Point | Fact |
|---|---|
| 1 | Rentrop classification grades coronary collateral circulation on angiography. |
| 2 | It has four grades: 0, 1, 2, and 3. |
| 3 | Grade 0 = No collateral filling visible. |
| 4 | Grade 1 = Filling of side branches only, no epicardial filling. |
| 5 | Grade 2 = Partial filling of epicardial segment of the occluded artery. |
| 6 | Grade 3 = Complete filling of epicardial segment via collaterals. |
| 7 | Grades 2 and 3 indicate well-developed collaterals. |
| 8 | Grade 0 suggests absence of natural bypass vessels. |
| 9 | Collateral circulation helps protect myocardium during ischemia. |
| 10 | Rentrop classification is purely angiographic, not functional. |
| 11 | Collateral vessels develop gradually in response to chronic ischemia. |
| 12 | Good collaterals may reduce infarct size in coronary occlusion. |
| 13 | Even with Grade 3 collaterals, coronary flow reserve is usually less than a normal artery. |
| 14 | Collateral circulation is variable among patients with similar occlusions. |
| 15 | Rentrop is widely used in clinical research on coronary collaterals. |
| 16 | It is simple and reproducible but subjective to operator assessment. |
| 17 | Advanced imaging (CT, MRI, pressure wire) may provide functional collateral assessment beyond Rentrop. |
| 18 | Patients with Rentrop Grade 3 collaterals may remain asymptomatic despite severe coronary occlusion. |
| 19 | Rentrop grading helps guide prognosis and research but is not used alone for intervention decisions. |
| 20 | The system remains one of the most common methods of collateral grading in interventional cardiology. |
“Rentrop classification, coronary collaterals, angiographic grading, Grade 0, Grade 1, Grade 2, Grade 3, myocardial ischemia protection.”
