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Table 1: Summary of studies reporting presence of a second right coronary artery in human heart, data grouped into in situ and ex situ observations.
Sub-Total
Median
Hearts
Studied
186
408
2800
150
543
700
4787
476
25
243
106
103
2089
387
100
80
125
305
100
100
200
60
651
95
566
78
119
781
500
Second
RCA
Separate
Ostium
Shared
Ostium
Second RCA
Incidence
76
163
68
45
185
159
696
118
190
180
53
75
13
166
3
94
53
28
33
39
90
32
332
32
102
42
9
273
166
-
64
-
-
58
-
-
-
-
115
53
1
-
119
-
-
-
-
-
-
-
22
-
-
-
-
-
-
-
-
121
-
-
18
-
-
-
-
65
0
74
-
47
-
-
-
-
-
-
-
10
-
-
-
-
-
-
-
40.9
40.0
2.4
*
30.0
34.1
22.7
14.5
32.0
33.0
39.0
45.0
53.3
51.0
12.0
38.7
50.0
27.2
9.1
†
46.5
53.0
93.8
‡
10.4
54.4
33.7
18.0
53.8
7.6
§
35.0
33.2
Technique Ref
RI
RI
RI
RI
CT
CT
-
-
RI
VA
RI
VA
RI & VA
RI
VA
12
13
CC 14
CC (49), VA (54) 15
VA
CC
VA
VA
VA
MA
16
17
18
19
20
21
VA
VA
22
23
VA 24
CC (29), VA (90) 25
RI & VA 26
VA 27
7
8
9
10
11
-
6
-
4
5
1
2
3

Sub-Total
Median
Total
Median
38
23
100
23
148
25
154
50
7374
103
12161
125
6
17
25
8
52
8
46
34
2201
-
2897
-
-
-
-
-
28
8
-
-
-
-
-
-
-
-
-
-
24
0
-
-
-
-
-
-
15.8
73.9
¶
25.0
34.8
35.1
32.0
29.9
68.0
‡
29.8
35.0
23.8
34.8
VA
VA
VA
MA
MA
VA
VA
MA
-
-
-
-
Legend:
CT, 64slice computed tomography assessment (voxel size of 0.4×0.4×0.4 mm); CC, corrosion-cast assessment; MA, magnified dissection-based visual assessment; RCA, right coronary artery; Ref, literature source found in Table References of this online supplement; RI, radiographic imaging assessment; VA, dissectionbased visual assessment. ‘-‘ indicates information not included in manuscript. Numbers in parenthesis indicate number in subset.
Notes:
- Table includes consecutive case series (in as far as could be discerned from descriptions provided in the manuscripts) which looked at the incidence of multiple coronary ostia in the right aortic sinus
( i.e.
without subject-selection based on criteria such as indication of coronary abnormalities by angiography, or specific types of second RCAs).
- Some studies have shown an increase in second RCA incidence associated with age 9,10 and pathology.
10 If true, this will affect reported incidence in all studies based on the age and pathological status of the studied subjects.
- A majority of studies did not report incidence of separate and shared ostia, nor distinguish between the two possibilities, and thus some may have included only second RCAs with separate ostia, which would reduce overall prevalence in those reports.
Possible explanations for uncharacteristically low (<10%) or high (>60%) second RCA incidence:
* Attributed by the authors to the concept that visualizing a second RCA by angiography occurs only by chance
† No apparent explanation
‡
May be a result of including second RCAs with shared ostia
§
Attributed by the authors to a difference in the Iraqi population
¶ Attributed by the authors to the concept that many second RCAs are missed in other studies due to its small size
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-
-
-
28
29
30
31
32
33
34
35
-

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