During the fifth week of foetal development vascular plexuses of sinusoids are formed in the sub-epicardial space. Coronary buds on the aortic sinuses connect with these plexuses leading to the development of coronary arteries.
1 Malformation within one of these systems may cause coronary anomalies; persistence of sinusoids results in coronary fistulae. Coronary anomalies affect approximately 1% of the general population. The importance of coronary anomalies varies from minor to life-threatening.
2-4 Apart from the clinical relevance, angiographic recognition of these anomalies is important because of the consequences for coronary intervention and coronary bypass grafting in these patients. The most frequently found anomalies include a circumflex artery with a separate ostium from the left anterior descending artery (LAD) originating in the left coronary cusp, an origin of the circumflex artery taking off from the right coronary artery or arising separately from the right coronary cusp (table 1).
Table 1
Incidence of coronary anomalies and dominance patterns, as observed in a continuous series of 1950 angiograms.
|
Coronary anomalies (total)
|
110
|
5.64
|
|
- Split RCA
|
24
|
1.23
|
|
- Ectopic RCA (right cusp)
|
22
|
1.13
|
|
- Ectopic RCA (left cusp)
|
18
|
0.92
|
|
- Fistulae
|
17
|
0.87
|
|
- Absent left main coronary artery
|
13
|
0.67
|
|
- Cx arising from right cusp
|
13
|
0.67
|
|
- LCA arising from right cusp
|
3
|
0.15
|
|
- Low origination of RCA
|
2
|
0.10
|
|
- Other anomalies
|
3
|
0.27
|
|
Coronary dominance patterns
|
|
|
|
- Dominant RCA
|
1641
|
89.1
|
|
- Dominant LCA (Cx)
|
164
|
8.4
|
|
- Co-dominant arteries (RCA, Cx)
|
48
|
2.5
|
…
