Classification of coronary artery aneurysms
classification of coronary artery aneurysms (CAA) by size 📏
🔹 Size-Based Classification of CAA
- Small CAA
- Diameter: < 5 mm
- Medium CAA
- Diameter: 5 – 8 mm
- Large / Giant CAA
- Diameter: > 8 mm
- Some definitions: > 20 mm or ≥ 4 times the reference vessel diameter (commonly used in Kawasaki disease literature).
✅ In Kawasaki disease guidelines:
- Small: < 5 mm
- Medium: 5–8 mm
- Giant: > 8 mm
✅ In adult cardiology literature:
- Giant CAAs sometimes defined as > 20 mm or ≥ 4× normal vessel diameter.
1. Which of the following defines a giant coronary artery aneurysm?
Correct: Giant CAA is defined as >20 mm or >4× reference artery diameter.
2. The most common cause of coronary artery aneurysms in adults is:
Correct: In adults, atherosclerosis accounts for the majority of CAAs.
3. In children, the most common cause of coronary artery aneurysms is:
Correct: Kawasaki disease is the leading cause of CAA in children.
4. Which morphological type of coronary artery aneurysm is characterized by a localized outpouching?
Correct: Saccular aneurysms are localized, “berry-like” outpouchings.
5. Fusiform coronary artery aneurysms are best described as:
Correct: Fusiform CAAs are elongated, diffuse dilatations of the vessel.
6. Which coronary artery is most commonly involved in aneurysms?
Correct: RCA is the most commonly affected artery in CAAs.
7. Which of the following is NOT a typical etiology of coronary artery aneurysms?
Correct: Hyperthyroidism is unrelated to CAAs.
8. Small coronary artery aneurysms are defined as:
Correct: Small CAAs are <5 mm or <1.5× the diameter of reference vessel.
9. Medium coronary artery aneurysms are:
Correct: Medium CAAs are 5–8 mm or 1.5–2× reference diameter.
10. Which complication is most feared with coronary artery aneurysms?
Correct: CAAs predispose to thrombosis → MI or distal embolization.
11. Kawasaki disease-related CAAs are most likely to affect:
Correct: Kawasaki disease typically affects young children.
12. Which imaging modality is gold standard for diagnosis of CAAs?
Correct: Coronary angiography is gold standard for detecting CAAs.
13. Mycotic coronary aneurysms are usually caused by:
Correct: Mycotic aneurysms result from infectious destruction of vessel wall.
14. The term “ectasia” refers to:
Correct: Coronary ectasia = diffuse dilation, not focal saccular aneurysm.
15. Iatrogenic CAAs are most commonly seen after:
Correct: CAAs can form after angioplasty or stent injury.
16. Which coronary artery is least commonly involved in aneurysms?


